Muck Vegetable Cultivar Trial Research Report . 2007

Muck Vegetable Cultivar Trial & Research Report .

2007

UNIVERSITY grGUELPH

Office of Research &: Dept. of Plant Agriculture Report No. 57

M. R. McDonald S. Janse K. Vander Kool

Muck Crops Research Station

Kettleby, Ontario

Research and Cultivar Trial Report for 2007

University of Guelph Office of Research &

Department of Plant Agriculture Muck Crops Research Station

1125 Woodchoppers Lane R.R. # 1 Kettleby, Ontario LOG lJO

Phone (905) 775-3783 Fax: (905) 775-4546

INDEX Page

Index .......................................................................................................................................................................... 1-3 Staff ............................................................................................................................................................................... 4 Co-operators .................................................................................................................................................................. 5 Seed Sources - 2007 ....................................................................................................................................................... 6 Legend of Seed Sources ................................................................................................................................................. 7 Introduction and Acknowledgements ............................................................................................................................. 8 Weather Data: Growing Degree Days ......................................................................................................... 9

Precipitation ................................................................................................................ 10-11 Mean Temperature ...................................................................................................... 12-13 Extreme Temperature .................................................................................................. 14-15

RESEARCH PROJECTS

Carrot

1. Control of Carrot Rust Fly & Carrot Weevil Using Various Insecticides, 2007 ............................................ 16-17 2. Comparison of Various Seed Treatments for Control of Carrot Rust Fly and Carrot Weevil

in Carrots, 2007 ..................................................................................................................................... 18-19 3. Comparison of Various Carrot Cultivars for Resistance to Carrot Rust Fly and Carrot Weevil

in Carrots, 2007 ............................................................................................................................................. 20 4. Evaluation of Different Coloured Carrots for Susceptibility to Cavity Spot, 2007 ....................................... 21-23 5. Evaluation of Fungicides on Carrots Inoculated with Sclerotinia sclerotiorum for Sclerotinia Rot of Carrot

Disease Control, 2006-2007 ..................................................................................................................... 24-25 6. Effect of Nitrogen Rate and Number of Fungicide Applications on Carrot Yield and the Severity of Alternaria

and Cercospora Leaf Blight, 2007 ........................................................................................................... 26-30 7. Carrot Tolerance to Command, 2007 .................................................................................................................. 31 8. Herbicide Combinations for Weed Control in Carrots, 2007 ........................................................................ 32-33 9. Aim for Directed Postemergence Between the Row Weed Control in Carrots, 2007 ......................................... 34 10. Critical Weed-Free Period in Carrots, 2007 .................................................................................................. 35-38

Celery

11. Nitrogen and Calcium and their Influence on Celery Yield and Quality, 2007 ............................................. 39-46

Cole Crops

12. Evaluation of Bravo Zn for Control of Downy Mildew (Peronospora parasitica) on Napa Cabbage, 2007 ..... .47 13. Evaluation of Revus for Control of Downy Mildew (Peronospora parasitica) on Napa Cabbage, 2007 ..... 48-49

.. .!continued

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RESEARCH PROJECTS - continued Page

14. Effect of Seeding Date and Harvest Intervals on the Development of Clubroot on Asia Vegetables, 2007 ..................................................................................................................................... 50-51

15. Tolerance of Transplanted Chinese Cabbage to Prowl, Aim & Eco-Clear, 2007 ....................................... 52-53 16. Comparison of Transplants Grown with the Addition of Worm Castings or a Ranman Drench for the

Control of Clubroot of Cabbage, 2007 .................................................................................................... 54-55 17. Evaluation of Revus for Control of Downy Mildew (Peronospora parasitica) on Cauliflower, 2007 ....... 56-57 18. Evaluation of Bravo Zn for Control of Leaf Blight (Alternaria brassicicola) on Cauliflower, 2007 ......... 58-59

Lettuce

19. Evaluation of a Biological Fungicide for Control of Sclerotinia Drop on Inoculated Lettuce, 2007 .......... 60-61 20. Tolerance of Transplanted Romaine & Iceberg Lettuce to Prowl AIM & Eco-Clear, 2007 ....................... 62-63

Onion

21. Evaluation of Various Seed Treatments for Control of Onion Maggot & Onion Smut in Yellow Cooking Onions, 2007 ......................................................................... , ................................................ 64-65

22. Field Evaluation of Commercial Yellow Cooking Onion Cultivars Interplanted with Onions Treated with Insecticide for Resistance to the Onion Maggot, Delia Antiqua, 2007 ......................................... 66-67

23. Comparison of Various Onion Varieties for Resistance to Downy Mildew (Peronospora destructor) in Onions, 2007 .................................................................................................................................... 68-69

24. Efficacy of Bravo Zn for the Control of Botrytis Leaf Blight on Onions, 2007 ......................................... 70-71 25. Efficacy of Serenade for the Control of Botrytis Leaf Blight on Onions, 2007 .................... ; ..................... 72-73 26. Herbicide Combinations for Weed Control in Onions, 2007 ...................................................................... 74-75 27. Field Evaluation of Liquid Calcium Chloride on Onion Yield and Quality, 2007 ...................................... 76-77 28. Evaluation of Phytotoxicity of Various Seed Treatments on Shallots, Leeks, and Fistulosum Bunching

Onions, 2007 .................................................................................................................................... 78-80 29. Identification of Efficient Sprayer Application Tools to Maximize Onion Thrips Control, 2007 .............. 81-85 30. Tolerance of Green Onions to Selected Herbicides, 2007 .................................................................. : ....... 86-87 31. Frontier & Outlook, Tolerance and Efficacy in Green Onions, 2007 ......................................................... 88-89 32. Tolerance of Transplanted Leeks to Selected Herbicides, 2007 ................................................................. 90-91

Miscellaneous

33. Evaluation of Revus 250 SC for Control of Downy Mildew of Cucumber, 2007 ...................................... 92-93 34. Evaluation of Fungicides and Foliar Fertilizers on Belgian Endive Root Yield, Petiole Discolouration

and Sclerotinia Rot Severity, 2007 ........................................................................................................ 94-95 35. Investigation of Pathogenic Fungi Affecting Quality & Storage of Belgian Endive, 2007 ......................... 96-98 36. Evaluation of A Biological Fungicide for Control of White Mold on Inoculated Snap Beans, 2007 ............... 99 37. Evaluation of Various Fungicides for Control of Powdery Mildew & Ascochyta Blight in

Succulent Peas, 2007 ........................................................................................................................ 100-101 38. Evaluation of Fungicides for Control of Black Rot of Squash, 2007 ...................................................... 102-103

Greenhouse Trials

39. Greenhouse Screening for Onion Smut Incidence of Various Onion Accessions and Cultivars from the U.S. National Plant Germplasm System, 2003-2006 .................................................................. 104-111

40. Evaluation of Ranman 400 SC for Control of Pythium spp. in Greenhouse Grown Vegetables for Field Transplanting, 2007 ................................................................................................................. 112-114

41. Evaluation of Worm Castings for the Production of Vegetable Transplants, 2007 ................................ 115-121

.. .Icontinued

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CROP:PESTS:

Carrot (Daucus carota subsp. sarir rrs r Htrilm. r -{rcang.) cv. Six ShooterCarrot Rust Fly, (Psila rosae (Fabric-ius, rCarrot Weevil, (Listronotus oreqonensis rLeConte rr

AUTHORS: MCDONALD MR & VANDER KOOI KUniversity of Guelph, Dept. of Plant Agriculture. Iluck Crops Research Station

TITLE: CONTROL OF CARROT RLTST FL\'.{\D CARROT WEEVIL USINGVARIOUS INSECTICIDES. 2OO7

MATERIALS: ADMIRE (imidacloprid24Va), ACTARA t.thiamethoxam25Vo), SUCCESS (spinosad44.27o), MATADOR (lambda-cyhalothrin I3.lVa). RIPCORD (cy'permethrin 40Vo) and IMIDAN(phosmet 307o)

METHODS: The trial was conducted at the Muck Crops Research Station, Holland Marsh, Ontario, inorganic soil (pH =6.4, organic matter =71.87o). Carrots u'ere direct seeded (75 seeds/m) on raised bedsusing a Stan Hay Precision seeder on 28 May. A randomized complete block arrangement with fourreplicates per treatment was used. Each replicate consisted of four rows, 86 cm apart and 5 m in length.Treatments were applied on 3, 30 July and 10 August using a pull type plot sprayer with TeeJet D-3hollow cone nozzles at 690 kPa (boom) in 500 Llha of water. Treatments were: ADMIRE at 500 mllha,ACTARA at200rnl-/ha, MATADOR at 83ml-lha, SUCCESS at370 mliha. One application of IMIDANat2.25 kg/ha followedby 2 applications of RIPCORD at 175 ml/ha was included as a standard treatment.An untreated check was also included. At harvest on 19 October a 2.32 m yield sample was taken fromeach replicate. All treatments were washed in a small drum washer to reveal damage caused by bothcarrot rust fly and carrot weevil. Assessments were made by inspecting each carrot for damage andcalculating the percent of carrots damaged by either pest. Healthy carrots were then graded according tosize, weighed and counted. The air temperatures in 2CfJ7 were below the long term (10 year) average forJuly (19.2"C), average for May (12.6"C), June (18.8"C), August (19.1"C) and September (16.2'C) andabove average for October (12.5'C). The long term (10 year) average temperatures were: May 12.5'C,June 18.3oC,July 20.2"C, August 19.1oC, September 15.7'C and October 9.1"C. Monthly rainfall wasbelow the long term (10 year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm),September (40 mm) and October (32 mm). The long term (10 year) rainfall averages were: May 80 mm,Jtne77 mm, July 61 mm, August 57 mm, September 74 mm and October 56 mm. Data were analyzedusing the General Analysis of Variance function of the Linear Models section of Statistix V.7. Meansseparation was obtained using Fisher's Protected LSD test at P=0.05 level of significance.

RESULTS: As presented in Table I

CONCLUSIONS: Damage caused by carrot rust fly and carrot weevil was low in 2007. No significantdifferences were found among the treatments in the percentage of damage caused by carrot rust fly orcarrot weevil. No significant differences in yield were found. No phytotoxicity was found among thefteatments.

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Table 1. Evaluation of insecticides for the control of carrot rust fly (Psila rosae) and carrot weevil(Listronotus oregonensis) on carrots grown at the Muck Crops Research Station, Holland Marsh, Ontario,2007.

Treatment Rate Rust Fly Weevil Percent Marketable(ml/ha) Damage (Vo) Damage (Vo) Marketable Yield (t/ha)

ACTARA

SUCCESS

RIPCORD/IMIDANI

MATADOR

Check

ADMIRE

200

370

175/2.25

83

500

0.4 nsl

0.5

2.9

0.5

2.4

0.7

4.6 ns

4.5

3.5

6.1

7.5

4.2

87.Zns

87.r

85.9

82.9

82.5

81.8

35.7 ns

34.8

34.2

36.r

33.r

32.8

'RIPCORD applied 2 times, IMIDAN applied 1 time.

'ns = no significant differences were found among the treatments

Funding for this project was supplied by the OMAFRAruniversity of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under Canada-OntarioResearch & Development (CORD) program, an initiative of the federal-provincial-territorialAgricultural Policy Framework designed to position Canada's agri-food sector as a world leader,The Agricultural Adaptation Council administers the CORD program on behalf of the province.

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CROP:PESTS:

Carrot (Daucus carota subsp. srztilrrs tHoffm..tArcang.) cv. CellobunchCarrot Rust Fly, (Psila rosae (Fabricius ttCarrot Weevil, (Listronottrs ore gonensi s (LeConte))

AUTHORS: MCDONALD MR. VANDER KOOI K & TAYLOR A

TITLE:

University of Guelph, Dept. of Plant Agriculture, Muck Crops Research Station

COMPARISON OF VARIOUS SEED TREAT]IIENTS FOR RESISTANCE TOCARROT RUST FLY AND CARROT WEEVIL IN CARROTS,2OO7

MATERIALS: THIRAM 42S (thiram 42Vo), ENTRUST (spinosad), CRUISER (thiamethoxam),Ll1 7 8- A (clothianidin)

METHODS: The trial was conducted near the Muck Crops Research Station, Holland Marsh, Ontario, inorganic soil (pH = 6.8, organic matter = 45Vo). Carrots were direct seeded (75-80 seeds/m) onto raisedbeds using a push V-belt seeder on 29 May. A randomized complete block arrangement with fourreplicates per treatment was used. Each replicate consisted of two rows, 86 cm apart and 5 m in length.Treatments were: ENTRUST at 2.5 g ai, ENTRUST at3.75 g ai, ENTRUST at 7.5 g ai, CRUISER at 2.5g ai, CRUISER at 3.75 g ai,Ll778-A at 5.6 g ai and L1778-A at7.5 g ai. An untreated check was alsoincluded. All seed ffeatments were expressed as g all00 g of seeds and all treatments included 250 mg aiTHIRAM (fungicide). At harvest on 24 October a2.32 m yield sample was taken from each replicate. Alltreatments were washed in a small drum washer to reveal damage caused by both carrot rust fly and carrotweevil. Assessments were made by inspecting each carrot for damage and calculating the percentage ofcarrots damaged by either pest. The air temperatures in 2OO7 were below the long term (10 year) averagefor July (I9.2"C), average for May (I2.6"C), June (18.8'C), August (19.7"C) and September (16.2"C) andabove average for October (12.5'C)- The long term (10 year) average temperatures were: May 12.5'C,June 18.3oC, July 20.2"C, August 19.1'C, September 15.7"C and October 9.1'C. Monthly rainfall wasbelow the long term (10 year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm),September (40 mm) and October (32 mm). The long term (10 year) rainfall averages were: May 80 mm,Jtne 7J mm, July 61 mm, August 57 mm, September 74 mm and October 56 mm- Data were analyzedusing the General Analysis of Variance function of the Linear Models section of Statistix V.7. Meansseparation was obtained using Fisher's Protected LSD test at P = 0.05 level of significance.

RESULTS: As presented in Table 1

CONCLUSIONS: Damage caused by carrot rust fly (>8Vo) and carrot weevil (>47o) was low in2007.Significant differences in percent carrot weevil damage were found among the treatments. Carrots grownfrom seed treated with both rates of L1778-A and ENTRUST at3.75 g ai had less carrot weevil damagethan carrots grown from seed treated with ENTRUST at 2.5 g ai and the check. No significant differenceswere found among the treatments in percentage of damage caused by carrot rust fly. No significantdifferences in yield were found (Table 1).

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Table 1. Effects of seed treatments for the confol of carrot rust fly and carrot weevil in carrots grown atHolland Marsh, Ontario 2007.

TreatmentRate g Vo Carrot Weevil 7o Carrot Rust Marketableail100 g Damage Fly Damage Yield (t/ha)

ENTRUST

Lt778-A

LT778.A

ENTRUST

CRUISER

CRUISER

ENTRUST

Check

0.1 ar

0.4 a

0.8 a

1.5 ab

1.5 ab

1.5 ab

3.0 b

3.4b

7.2ns2

5.4

8.0

4.6

4.3

7.8

7.g

5.6

84.8 ns

86.3

78.3

93.2

72.4

88.8

80.0

86.s

3.75

7.5

5.6

7.5

2.5

3.75

2.5

Not significantly different, P = 0.05 Fisher's hotected LSD Test.'Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSD test.

Funding for this project was supplied by the OMAFRA iniversity of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under Canada-OntarioResearch & Development (CORD) program, an initiative of the federal-provincial-territorialAgricultural Policy Framework designed to position Canada's agri-food sector as a world leader.The Agricultural Adaptation Council administers the CORD program on behalf of the province.

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CROP:PBSTS:

AUTHORS:

TITLE:

ResistaflySytan

Carrot (Daucus carota subsp. sativus (Hoffm.) Arcang.) cv. variousCarrot Rust Fly, (Psila rosae (Fabricius))

Carrot Weevil, (Listronotus oreg,onensis (LeConte))

MCDONALD MR & VANDER KOOI KUniversity of Guelph, Dept. of Plant Agriculture, Muck Crops Research Station

COMPARISON OF VARJOUS CARROT CULTIVARS FOR RESISTANCE TOCARROT RUST FLY AND CARROT WEEVIL IN CARROTS,2OO7

MATERIALS: Resistafly - Vesey's Seeds, Sytan & Fly Away - Thompson & Morgan, Cellobunch -

Stokes Seeds

METHODS: The trial was conducted near the Muck Crops Research Station, Holland Marsh, Ontario, in

organic soil (pH = 6.8, organic matter = 45Vo).Carrots were direct seeded (75-80 seeds/m) onto raised

beds using a push V-belt seeder on 29 May. A randomized complete block arrangement with four

replicates per treatment was used. Each replicate consisted of two rows, 86 cm apart and 5 m in length. At

harvest on 24 October a232 m yield sample was taken from each replicate. All treatments were washed

in a small drum washer to reveal damage caused by both carrot rust fly and carrot weevil. Assessmentswere made by inspecting each carrot for damage and calculating the percentage of carrots damaged byeither pest. The air temperatures in 2007 were below the long term (10 year) average for July (I9.2"C),

average for May (LZ.6"C), June (18.8'C), August (I9.7"C) and September (16.2"C) and above average

for October (12.5"C). The long term (10 year) average temperatures were: May 12.5'C, June 18.3oC, July20.2"C, August 19.1'C, September 15.7'C and October 9.1"C. Monthly rainfall was below the long term(10 year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm), September (40 mm)and October (32 mm). The long term (10 year) rainfall averages were: May 80 mm, IuneJT mm, July 61mm, August 57 mm, September 14 mm and October 56 mm. Data were analyzed using the GeneralAnalysis of Variance function of the Linear Models section of Statistix V.7. Means separation wasobtained using Fisher's Protected LSD test at P = 0.05 level of significance.


CONCLUSIONS: Damage caused by carrot rust fly (>l}Vo) and carrot weevil (>57o) was low in 2007.

No significant differences were found among the treatments in percentage of damage caused by carrotrust fly or caffot weevil. Significant differences in yield were found. All three resistant carrot cultivars areNantes type carrots and are not as high yielding as Cellobunch.

Table 1. Comparison of carrot cultivars with resistance to carrot rust fly in Holland Marsh, Ontario 2007.

.l.reatment Vo Canot Rust Fly 7o Canot Weevil Marketable Yield

Fly Away

9.53.45.6

0.71.22.6

55.0 b60.4b60.5 b

' Not significantly different, P=0.05 Fisher's Protected LSD Test.v Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSD test.

Funding for this project was supplied by the OMAFRAruniversity of Guelph Sustainable Production Systems

Program and by Canada and the Province of Ontario under Canada-Ontario Research & Development(CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed

to position Canada's agri-food sector as a world leader. The Agricultural Adaptation Council administers the

CORD program on behalf of the province.

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CROP:PEST:

AUTHORS:

TITLE:

Carrot (Daucus carota subsp. sativus (Hoffm.) Arcang.)Cavity spot (Pythium intermedium deBary, Pythium irregulare Buisman, Pythium

sulcatum Pratt & Mitchell, Pythium sylvaticum W.A. Campbell & J.W. Hendrix, Pythiumultimum Trow and Pythiumviolae Chesters & C.J. Hickman)


EVALUATION OF DIFFBRENT COLOURED CARROTS FORSUSCEPTIBILITY TO CAVITY SPOT, 2OO7

MATERIALS: Commercial carrot cultivars from Bejo Seeds Inc., Johnny's Selected Seeds, Seminis

Vegetable Seeds, Alpha Seed, South Africa and a red cultivar from India.

METHODS: The trial was conducted on organic soil (pH = J.0, organic matter = 44.0Vo) naturally

infested with Pythium spp. near the Muck Crops Research Station, Holland Marsh, Ontario. A

randomized complete block design with four replicates per treatment was used. Carrots were direct

seeded (70-80 seeds/m) on raised beds using a push V-belt seeder on 29 May. Each replicate consisted of

two rows, 86 cm apart,6 m in length. On 16 August, a random sample of 25 canots was removed from

each treatment and assessed for cavity spot. A 50 carrot sample was harvested on 25 and 26 October,

placed into cold storage and assessed for cavity spot on 11 December. On both assessment dates carrots

were washed in a small drum carrot washer, examined for cavity spot lesions and sorted into classes based

on the size of the largest lesion (measured as horizontal length). The six classes were as follows: no

disease; very light < lmm; light l-2 mm; medium 3-5 mm; heavy 6-10 mm; very heavy > 10 mm. Carrots

were grouped by colour and by cultivar when assessed for disease incidence and severity. The disease

severity index (DSI) was determined by the following equation:

DSI =rp [(class no.)(no. of carrots in each class)]

x 100(total no. carrots per sample)(no. classes -1)

The air temperatures in 2007 were below the long term (10 year) average for July (I9.2"C), average for

May (12.6"C), June (18.8'C), August (19.7'C) and September (16.2'C) and above average for October(12.5"C). The long term (10 year) average temperatures were: May 12.5'C, June 18.3'C, htly 20.2"C,

August 19.1'C, September ls.l"C and October 9.1'C. Monthly rainfall was below the long term (10

year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm), September (40 mm) and

October (32 mm). The long term (10 year) rainfall averages were: May 80 mm, June J7 mm, July 61 mm,

August 57 mm, September 74 mmand October 56 mm. Data were analyzed using the General Analysis of

Variance function of the Linear Models section of Statistix 7. Means separation was obtained using

Fisher's Protected LSD test at P = 0.05 level of significance.

RESULTS: As presented in Tables I and2

CONCLUSIONS: On the early assessment date no significant differences were found among cultivars

for disease incidence and disease severity index. Less cavity spot was present early in the season (Table

1). Significant differences were found among the cultivars for disease incidence and disease severity

when assessed on 11 December. The commercial variety Purple Rain had significantly lower incidence

and severity of cavity spot than varieties Mellow Yello, Cellobunch, Cosmic Purple, Atomic Red and the

Indian carrot. The lndian carrot had significantly higher incidence and severity of cavity spot than all

other cultivars.When canots were grouped by colour, significant differences were found for disease incidence and

disease severity on the late assessment date (Table 2). Purple, orange, yellow and white colour groups had

aa

significantly lower incidence and severity of cavity spot than the red colour group. Carrot pigment mayinfluence the susceptibility of carrots to cavity spot.

Table 1. Disease incidence and disease severity index (DSI) of cavity spot in different coloured carrots,grown at the Muck Crops Research Station, Holland Marsh, Ontario,2007.

Disease Incidence (7o) DS13Cultivar Sourcel Colour2

16 Aug 1l Dec 16 Aug 11 Dec

Indian

Atomic Red

Cosmic Purple

Cellobunch

Mellow Yello

White Satin

YaYa

Crdme de Lite

Alpha Better F1

Envy

Purple Haze

Purple Rain

I

JSS

JSS

Sem

Bejo

Bejo

Bejo

Nun

25.3 ns

8,0

5.3

3r.3

22.7

20.0

9.3

r7.3

22.7

19,3

10.7

9.3

5).E a-

359 b

30.0 bc

24.5 bcd

22.0bcd

19.0 cde

15.3 cde

14.5 cde

14.5 cde

13.0 de

9.5 de

5.5 e

16.5 ns

3.5

3.2

15.6

r0.4

12.5

4.8

r0.4

13.3

r0.7

6.4

4.8

38.7 a

23.9b

15.0 bc

I4.3 bc

13.7 bc

11.6 cd

8.8 cd

8.2 cd

8.0 cd

7.3 cd

5.3 cd

2.7 d

Alpha

Sem

Bejo

Bejo

R

R

P

oY

woY

ooP

PSources: I = India, JSS = Johnny's Selected Seeds, Sem= Seminis Vegetable Seed, Bejo = Bejo Seeds Inc, Nun =

Nunhems, Alpha = Alpha Seed, S.A.' Colour: O = Orange, P = Purple, R = Red, W = White, Y = Yellow.'Disease severity index (DSI) was determined using the following equation:

I l(class no.)(no. ofcarrots in each class)l(totar no. carrots per sample)(no.

"tiiGj- * lffi

o Numbers in a column followed by the same letter were not significantly different at P=0.05, Fisher's Protected LSD Test

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Table 2. Disease severity @SI) of cavity spot of different coloured carrots grouped by colour, grown atMuck Crops Research Station, Holland Marsh, Ontario, 2007.

Disease Incidence (7o) DSTColourr

16 August 11 December 16 August 11 December

Red 16.7 ns3 45.9 aa 10.0 ns 3I.3 a

white 17.3 19.0 b 10.4 11.6 b

Yellow 21.3 18.3 b 11.5 11.0 b

Orange 2I.I 16.8 b Il.2 9.6 b

Purple 8.4 15.0 b 4.8 7.7 b

' Cultivars of similar colour were grouped for analysis

'Disease severity index (DSI) was determined using the following equation:

I l(class no.)(no. ofcanots in each class)]lJJl = A rvv

(total no. carrots per sample)(no. classes -l)3 rrs = no sienificant differences found among the treatmentso Numb".s In a column followed by the samJ letter were not significantly different at P=0.05, Fisher's Protected LSD Test.

Funding for this project was supplied by the OMAFRAruniversity of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under the Canada-Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-food sector as aworld leader. The Agricultural Adaptation Council administers the CORD program on behalf ofthe province.

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CROP:PEST:

AUTHORS:

TITLE:

Carrot (Daucus carota), cv. EnterpriseSclerotinia rot of carrot, (Sclerorirtia sclerotiorum (Lib.) de Bary)

MCDONALD MR, VANDER KOOI K & GOSSEN, BDUniversity of Guelph, Dept. of Plant Agriculture, Muck Crops Research Station

EVALUATION OF FUNGICIDES ON CARROTS INOCULATED WITHSCLEROTINIA SCLEROTIORUM FOR SCLEROTINIA ROT OF CARROTDISBASE CONTROL, 2006.2007

MATERIALS: PRISTINE (pyraclostrobin 12.8Vo, boscalid 25.ZVo), LANCE (boscalid 707o)

MBTHODS: Carrots cv. Enterprise (Stokes Seeds) were direct seeded (82 seeds/m) on raised beds, intoorganic soil (pH = 6.3, organic matter = l2.4%o) on 25 May 2006 using a Stan Hay Precision seeder at theMuck Crops Research Station, Holland Marsh Ontario. A randomized complete block arrangement withfour replicates per treatment was used. Each experimental unit consisted of eight 5 m long rows, 42 cmapart. Treatments were: PRISTINE at 737 glha on carrots inoculated and not inoculated with sclerotiniaand LANCE at 630 g/ha on carots inoculated and not inoculated with sclerotinia. An untreated, non-inoculated check and an untreated inoculated check were also included. Treatments were applied on 4, 11,20 and 26 August, and 6 September using a pull+ype plot sprayer with TeeJet D-3 hollow cone nozzles at690 kPa (boom) in 500 Llha of water. To prepare inoculum, filter paper was soaked in PDA, inoculatedwith Sclerotinia sclerotiorum, allowed to grow and cut into strips 0.i x 3 cm. On 10 August treatmentswere inoculated by evenly spreading paper strip inoculum, 4.67 glm, on the soil in the 2 intercrop rowsper experimental unit. On 18 October 2006 the trial was assessed for disease occurrence and healthy andinfected plants were counted and the numbers recorded. At harvest on 27 October 2006, a 2.32 m yieldsample was pulled and roots were placed in storage. On I Novemb er 2O06, the yield sample was weighedand graded for size. On 27 October 2006, 2 storage samples, bulk and individual, were taken. One plastictote of carrots per experimental unit was placed in storage to assess sclerotinia in a bulk sample and 50individual roots from each experimental unit were placed in 5 x25 cm DeepotsrM, supported by Deepotrucollars, placed in 2 layers within wooden storage boxes, to assess sclerotinia development in individualcarrots. Both samples were placed in Filacell storage at = 1o C, 957o RH. On 26 June 2007, the bulkstorage sample was removed, assessed for disease, and healthy and diseased carrots weighed. On 2October, the individual storage sample was removed from storage, and the carrots examined forsclerotinia. The air temperatures in 2006 were below the long term (10 year) average for September(14.3'C), average for June (18.4'C), August (19.2"C) and October (7.9"C) and above average for May(I3.7'C) and July (2L9'C). The long term (10 year) average temperatures were: May I2.4"C, June18.3'C, July 20.3"C, August 19.1'C, September 15.6'C and October 8.8oC. Monthly rainfall was belowthe long term (10 year) average for May (64 mm), June (64 mm) and August (41 mm) and above averagefoq July (72 mm) September (174 mm) and October (102 mm). The long term (10 year) rainfall averageswere: May 82 mm, June 81 mm, July 65 mm, August 59 mm, September 82 mm and October 56 mm.Data were analyzed using the General Analysis of Variance function of the Linear Models section ofStatistix V.7. Means separation was obtained using Fisher's Protected LSD test at P = 0.05 level ofsignificance.


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CONCLUSIONS: Both inoculated and non-inoculated carrots treated with LANCE and non-inoculatedcarrots treated with PRISTINE had a lower percent sclerotinia infection in the field than inoculatedcarrots treated with PRISTINE and the inoculated check (Table 1). There was no significant differenceamong the treatments in yield of either inoculated or non-inoculated carrots. There were no significantdifferences in percent diseased carrots among the treatments after 8 months and up to 18.9 percent ofcarots were diseased in bulk storage but this included carrots that were diseased for all reasons (Table 1).However, no sclerotinia was observed in the individual storage samples. This may be due to the efficiencyof the Filacell storase.

Table 1. Evaluation of LANCE and PRISTINE for control of sclerotinia rot in carrots inoculated withSclerotinia sclerotiorum grown and stored at Holland Marsh, Ontario, 2006 - 2007.

Treatment InoculationRate Vo Infection 7o Marketable

Glha) in field1 at harvestYield 7o Diseased(t/ha) after storagea

LANCE Non-inoculated 630 75.3 a2

PRISTINE Non-inoculated 737 77.4 a

LANCE Inoculated 630 78.0 a

Check Non-inoculated 91.3 ab

PRISTINE Inoculated

Check Inoculated

737 94.1b

95.6 b

80.6 ns3 13.6 ns

78.',7 18.3

84.0 18.9

77.4 r2.3

82.8 t4.0

13.6 10.3

83.4 ab

84.2 ab

83.9 ab

86.6 a

88.6 a

78.9 b'Carrots in I m section counted and examined for disease2Numbers in a row followed by the same letter are not significantly different at P = 0.05, Fisher's Protected LSDtest.3 Not significantly different at P = 0.05, Fisher's Protected LSD test." This includes carrots diseased for all reasons

Funding for this project was supplied by the OMAFRA/University of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under the Canada-Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-food sector as aworld leader. The Agricultural Adaptation Council administers the CORD program on behalf ofthe province.

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CROP:PESTS:

Carrot (Daucus carota subsp. sativus (Hoffm) Arcang. cv. EnterpnseAlternaria leaf blight (Alternaria dauci (Knln) Groves & Skolko)Cercospora leaf blight (Cercospora carotae (Pass.) Solheim)

AUTHORS: SAUDE C. MCDONALD MR & VANDER KOOI K

TITLE:


EFFECT OF NITROGEN RATE AND NUMBER OF FUNGICIDEAPPLICATIONS ON CARROT YIBLD AND THE SEVERITY OFALTERNARIA AND CERCOSPORA LEAF BLIGHT.2OOT

MATERIALS: BRAVO (chlorothalonll5O7o), LANCE (boscalid 707o), CABRIO (pyraclostrobin20%o),AMMONIUM NITRATE (34Vo N)

MBTHODS: The trial was conducted on mineral soil (pH = 7.9, organic matter = 4.9Vo) near the MuckCrops Research Station, Holland Marsh, Ontario. Carrots were grown and harvested on the site in 2006 toremove soil nitrogen. No N was applied to the trial in 2006. Carrots were direct seeded (80 seeds/m) onraised beds using a Stan Hay Precision seeder on 22 May 2A07. A randomized complete blockarrangement with four replicates per treatment was used. Each replicate consisted of four rows, 86 cmapart and 8 m in length. The 10 treatments were: three rates of N (0, 110, and 220kglha) in combinationrvith four fungicide timings (0, 3, 5 applications at full rate and 5 applications at half rate). Previousresults showed that total yield was maximized with five fungicide applications, thus, in this trial; a halfrate of the five fungicide applications was included for the evaluations.

The various rates of N were applied by hand as AMMONILM NITRATE applied 2/3 preplant and l/3side dress. After N applications, plots were irrigated to incorporate the N into the soil. The fungicideswere applied 17,29 Aug and 17 Sep (three applications), and 17, 29 Aug and 10, 17,21 Sep (fiveapplications (full and half rates). LANCE (315 g/ha BASF Canada lnc.) was used for fungicideapplication on 17 Aug; and 10 Sep. BRAVO (3.0 L/ha Syngenta Crop Protection) was used for fungicideapplication on 29 Aug and27 Sep and CABRIO (1.1 kg/ha BASF Canada Inc.) was used for fungicideapplication on 17 Sep. Fungicides were applied using a pull-type plot sprayer with TeeJet D-3 hollowcone nozzles at 690 kPa (boom) in 500 Llha of water. Inoculum of Alternaria and Cercospora occursnaturally. Weeds and fertilization were managed according to OMAFRA standard production practices.

Once symptoms of leaf blight developed in the plot, the foliage in each treatment was rated for bothalternaria and cercospora leaf blight biweekly up to 1 week before harvest on a scale of 0 to 10 (0 = nosymptoms, 2 = l0 to 20 lesions on leaves 4 = 30 to 40 lesions on leaves and 10 to 20 lesions on petioles, 6=> 60 lesions on leaves and > 40 lesions on petioles, 8 = 214 of leaves destroyed, 10 = all leavesdestroyed). Biweekly disease ratings were used to calculate area under the disease progress curve(AIIDPC) using the equation:

ni-1

AUDpc Z eI#,,(ti*,_ti.j=t

Where: ),= leaf blight severity rating at jth observation, /= time (days) since the previous rating at theTthobservation and n = total number of observations.

To assess the strength of petioles for mechanical harvest, the foliage of ten carrots was removed fromeach treatment on 26 October and assessed for disease incidence and severity. Tops were assessed for the

-21-

amount of dead leaves/petioles and for disease severity based on a six class scale: 0 = no disease; t< ljVo

leaf area diseased; 2= I0-257o leaf area diseased; 3 =26-50Vo leaf area diseased; 4 = 5I-75Vo leaf area

diseased; 5 >75Vo leaf area dead/diseased. The disease severity index (DSI) was determined by the

following equation:

DSI =<p l(class no.Xno. of leaves in each class)] x 100(total no. leaves per sample)(no. classes -1)

Leaf blight symptoms at harvest were not separated based on causal organism. Carrot plants in the center

4.6 mmiddle rows of each treatment replicate were hand harvested on 31 October and 1 November' The

foliage was removed at the crown and carrot roots were evaluated for yield. Carrots were weighed for

total yield and separated into three sizelquality grades (roots > 4.4 cm diameter, roots 2.0 to 4.4 cm

diameter, and culls, including roots < 2-2 cmdiameter)'

The air temperatures in 2007 were below the long term (10 year) average for July (19.2"C), average for

May (12.6"-;, Jutr" (18.8'C), August (19.7'C) and September (I6.2'C) and above average for October

(i2.5"C). The long term (10 year) average temperatures were: May 12.5'C, June 18.3'C, July 20.2"C,

August 19.loc, September 15.7"C and October 9.1'C. Monthly rainfall was below the long term (10

y"ui; uu"ruge for May (43 mm), June (29 mm), July (27 mm), August (33 mm), September (40 mm) and

bctober (3imm). The long term (10 year) rainfall averages were: May 80 mm, IaneiJ mm, July 61 mm,

August 5'7 mm, SeptembeiT4 mm and October 56 mm. Data were analyzed using the General Analysis of

Variance function of the Linear Models section of Statistix V.7. Means separation was obtained using

Fisher's Protected LSD test at P = 0-05 level of significance.

RESULTS AND DISCUSSION: Carrot alternaria and cercospora leaf blight symptoms were first

recorded 3l July, about 70 days after planting. Plant growth and disease development was slow, and this

can be attributed to dry and hot weather conditions registered in early summer, 2007.

Nitrogen application had a significant effect on altemaria and cercospora leaf blights throughout the

,"uroi (Tables | & 2). The application of 200Vo of the N rate alone or combined with fungicides at three

and five rates significantly reduced alternaria leaf blight. The effect of 20AVo N rate with no fungicide

applications was comparable to the effect of no N and three fungicide applications. The highest alternaria

teaf Ungnt reduction was achieved when 200Vo N and three fungicides were applied. Similar result was

obtained with the application of 2007o N and five fungicide applications at full and half rates. Also, the

application of 200 7, N rate combined with three and five fungicides at full and half rates, significantly

reiu"ed cercospora leaf blight. Carrot foliar blight caused by both alternaria and cercospora at harvest

was high in treatments that received no N regardless of the fungicide rates applied as shown by the DSI

results:The application of l00%o and 200Vo of N rates combined with three fungicide applications resulted

in similar nu*b", of dead leaves and DSI value. The number of dead leaves was further reduced when the

five fungicides were applied in combination with no N and 200Vo of the recommended N rate.

Total and marketable yield as well as the percent culls were unaffected by N application rate alone, but

the application of 20O7oN rate significantly increased the quality of the crop as determined by the percent

of oversized carrots (Tables 3 & 4). Nevertheless, total and marketable yield of carrots increased

significantly with fungicide applications. The combination of no N and the application of five fungicides

at full rate resulted in the highest total and marketable yields. These results were not significantly

different from the results obtained from the combination of I00Vo N and five fungicide applications at full

rate, and Z00VoN and 5 fungicide applications at full and half rates. The yield increase obtained with the

combination of N and fungicide rates, was associated with a lower number of dead plant leaves and with

an increase in the percent of oversized carrots. Treated carrot plants had healthier foliage than non treated

carrot plants. Healthy foliage is essential for the carrot photosynthetic capacity which affects root growth.

ln this trial, carrots were hind harvested and all carrot roots were dug out from the soil, regardless of the

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foliage health. If the carrots were mechanically harvested, the yield differences between treated anduntreated carrots could have been larger, since blighted carrot petioles snap during mechanical harvest,leaving the roots in the ground.

The application of five fungicides at half rate provided similar results to the carrots that received 1007o Nrate and three and five fungicide applications at full rate or 200Vo N and three and five fungicides at fullrate, for alternaria and cercospora leaf blights. Disease severity index and the number of dead leaves werereduced with the application of the five fungicides at half rate (Table 1). Also, total and marketable yield,and the percent of oversized carrots was significantly higher with the application of five fungicides at halfrate (Table 2). These results are preliminary. The applications of the five fungicides at half rate was notevaluated with the 1007o N rate, nor is the half rate of the fungicides recommended by OMAFRA.However, the results of this study suggest that fungicide use can be more efficient when applied at thelower rate at more frequent intervals than at the full rate applied less frequently. Therefore, this evaluationrequires further investigation.

CONCLUSIONS: Nitrogen rate had an effect on alternaria and cercospora leaf blights and fungicideapplications reduced leaf blight and increased yield. The amount of alternaria blight that developed overthe season was the same on carrots that received 200Vo of the recommended N rate and no fungicides, asit was on carrots that received no N and three or five fungicides. Cercospora leaf blight was reduced withthe application of 2007o of recommended N rate and three and five fungicide sprays, with the threefungicide sprays providing better control. Total amount of alternaria and cercospora leaf blights (DSI)was reduced with the applications of the 2007o of the recommended N and five fungicides. This treatmentalso reduced the number of dead leaves. Total and marketable yield increased when carrots received fivefungicides at the full and half rates, regardless of the N rate. The highest yield was obtained when carrotswere treated with five fungicides and received no N. Applications of the half rate of the five fungicidescombined with the 200Vo of the recommended N rate provided results similar to those obtained with the200Vo of the recommended N rate and three and five fungicides at full rate.

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Table 1. Effects of nitrogen and fungicides on the severity of Alternaria and Cercosporaleaf blights asdetermined by area under disease progress curve (AUDPC) over the season, disease severity index (DSDand number of dead leaves at harvest for carrots grown on mineral soil near Muck Crops ResearchStation, Holland Marsh, 2007.

Treatment

N Rate (7o ofrecommended)'

Number ofFungicide

Applications

AlternariaLeaf Blight

AUDPC

CercosporaLeaf Blight

AUDPC

Disease Ly1\UmDer oISeventy Index w

@SD- ueao Leaves

000

100100100204200200200

0350J

50aJ

55 @I/2rate

487.5 aY42l.2bc420.0bc451.9 ab406.9 cd408.8 cd429.4bc343.1e352.5 e378.8 de

376.9 a363.8 a350.6 a360.0 a354.4 a345.0 a352.5 a298.rb273.8b290.6b

69.0 a51.0 b43.r d64.9 a47.5 bc40.1 cd61.6 a46.4bc26.0 e38.0 d

38.5 a21.8 cd12.8 ef34.0 ab17.8 def19.8 cde26.8bc15.0 def10.5 f13.0 ef

Recommended Nitrogen rate for mineral soils = 110 kglha split2l3 preplant, 1/3 side dress.v Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSDtest." Disease severity index (DSI) was determined using the following equation:

DSI =e [(class no.)(no. ofplants in each class)]

x 100(total no. plants per sample)(no. classes -l)

*Number of dead leaves evaluated from the foliage of 10 carrot plants

Table 2. Effects of nitrogen rates on foliar diseases, total yield, marketable yield and percent oversizedcarrots grown on mineral soil near Muck Crops Research Station, Holland Marsh, 2007.

DiseaseSeverityIndex(DSI).

N rate (7o of Alternaria Cercosporarecommended)' (AUDPC) (AI]DPC)

Total Marketable Vo o/^Yield Yield Oversize ^':.(t/ha) (t/ha) carrots

uulls

0100200

427.0 aY41I.6 a375.9 b

345.4 a337.5 a303.8 b

48.0 a47.6 a43.0 b

50.6 a5 1. la48.5 a

47.Ia47.6 a44.8 a

2.9b5.1 b9.9 a

7.2 a7.1 a7.7 a

" Nitrogen rate for mineral soils = I l0 kg/ha split 2/3 preplant, 1/3 side dressv Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSD

test.^ Disease severity index (DSI) was determined using the following equation:

e [(class no.)(no. ofplants in each class)]DSI =

(total no. plants per sample)(no. classes -l)x 100

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Table 3. Effects of fungicide ffeatments on foliar diseases, total yield, marketable yield and percentoversized carrots grown on mineral soil near Muck Crops Research Station, Holland Marsh, 2007.

DiseaseSeverityIndex(DSD'

#ofAlternarla

^ "ulg1:lo" z (AUDpc)Appllcatlons-

Marketable 7oYield (r/ha) u^verslze

culls. LAITOTS

Cercospora(AUDPC)

TotalYield(t/ha)

0 456.2 aY3 390.6 b5 393.8 b

5 @l/2 rate 378.8 b

363.1 a 65.2 a 44.2 c 40.7 c338.8 b 48.3 b 49.0b 45.3bc323.1b 33.4d 54.6a 51.1a290.6 c 38.0 c 52.4 ab 48.9 ab

2.1b6:6 ab6.2 ab9.0 a

8.4 a

7.9 a6.4 a6.7 a

" Fungicides LANCE (315 g/ha), BRAVO (3.0 L/ha) CABRIO (1.1 kg/ha) and application schedule over thegrowing season: 0= No fungicides , 3= 3 applications at full rate, 5= 5 applications at the full rate and 5@ lz = 5applications at half rate of fungicides. The fungicides were applied 17 ,29 Aug, and l'l Sep (3 applications); 17, 29Aug, and 10, 17 ,27 Sep (5 applications).v Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSDtest.* Disease severity index (DSI) was determined using the following equation:

DSI = e [(class no.)(no. ofplants in each class)]x 100

(total no. plants per sample)(no. classes -l)

Table 4. Effects of nitrogen and fungicides on total yield, marketable yield, percent oversized carrots andpercent culls grown on mineral soil near Muck Crops Research Station, Holland Marsh, 2007.

Treatment

Rate (7o of # of Fungiciderecommended)' Applications

7o oversize vo cu|,st_arrots

Total Yield(Uha)

MarketableYield (t/ha)

0100100100200

0-1

50aJ

0J

00

200200200

42.9 cY48.9 bc58.1 a47.7 bc49.2bc55.1 ab42.1c49.0bc50.4 abc52.4 ab

39.9 c44.8bc55.4 a44.3 bc46.1abc51.0 ab38.3 c45.0 bc46.9 abc48.9 ab

0.4 d0.7 d1.8 cd1.3 d4.7 bcd5.3 bcd4.9 bcd

14.4 alI.2 ab9.2 abc

9.1a8.5 a4.6 a7.1 a7.0 a7.5 a9.0 a8.9 a6.7 a6.1 a

55 (@Il2 rate

" Recommended Nitrogen rate for mineral soils = I l0 kgiha split2l3 preplant, 1/3 side dress.v Numbers in a column followed by the same letter are not significantly different at P=0.05, Fisher's Protected LSDtest.

This project was funded in part through contributions by Canada and the Province of Ontariounder the Canada-Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-foodsector as a world leader. The Agricultural Adaptation Council administers the CORD program onbehalf of the province.

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CROP: Carrot (Daucus carota.), cvs. Pursuit and Enterprise

AUTHORS: SWANTON CJ, JANSE S & CHANDLER K

TITLE:


CARROT TOLERANCB TO COMMAND,2007

MATERIALS : COMMAND (clom azone 3 6Vo)

OBJECTM: To evaluate the tolerance of carrots to COMMAND applied preemergence on muck soils

and to evaluate the tolerance of onions grown the following year'

METHODS: The trial was conducted at a site with organic soil (organic matter 75Vo,pH 6-5) on the Muck

Crops Research Station, Holland Marsh. Plots consisted of 2 hills, 86 cm apart and 4m long arranged in a

randomized complete block design with four replications. one hill was seeded with cv.Pursuit (processing

type) and the other hill was seeded with Enterprise (fresh market type) at a population of 77 seed /m on 18

Vf"y. The trial consisted of 4 treatments including an untreated control. COMMAND was applied

p.""-"rg"nce at the registered rate range, 280 and 560 gatlha, and II20 galha (2X) in 200 Llha on May

2g. All treatments werJ maintained weed-free. Recommended management practices for soil fertility and

pest control were followed. Visual assessments for crop injury and rveed control were conducted

periodically over the growing season. Carrots were harvested at maturity' Data was analyzed by ANOVA

ind means separated using Fisher's Protected LSD test (P=0'05)'

RBSULTS: As presented in Table 1

CONCLUSIONS: COMMAND applied preemergence at the proposed use rate range of 280 and 560

gailha and at the 2Xrate (1120 garlha) caused no crop inj.,ty or reductions in crop stand count on either cv'

Pursuit or cv. Enterprise carrots.There were differences in total yields of cv. Pursuit and cv. Enterprise carrots but for both varieties

COMMAND at the 2X dose gave the greatest yields indicating excellent crop tolerance. COMMAND

provided marketable yields of Uottr carrolvarieties that were similar to the untreated control. These confirm

the results of other studies that carrots grown on muck have good tolerance to COMMAND' Further

research is required to determine the tolerance of crops grown the year following the application of

COMMAND. On muck soils, onions are typically grown in rotation with carrots. In 2008 onions will be

seeded into the plots treated with COMMAND in 2001 and onion tolerance and yield will be determined.

Table 1. Carrot tolerance to COMMAND, MCRS,2007.cv. Pursuit

---- 15 June ---

Treatment Dose Injury Count Total Market(gaiiha) vo #/m row tlha

Injury Count

7o #/mrow

Total Market

tJha

Untreated

COMMAND 280

COMMAND 560

COMMAND TT2O

LSD (P=0.05)

438

037

040

034

NS NS

43

NS

I

5

0

0

NS

41

47

48

87.8

73.0

64.4

87.0

n.0

76.3

60.0

51.2

66.5

NS

62.8 51.3

7s.6 61.3

69.0 57.9

79.t 54.5

NS

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CROP: Carrot (Daucus carota.), cvs. Pursuit and Enterprise

AUTHORS: SWANTON CJ. JANSE S & CHANDLER K

TITLE:


HERBICIDE COMBINATIONS FOR WBED CONTROL IN CARROTS.2OOT

MATERIALS: GESAGARD (prometryne 487o) LOROX (linuron 507o), SENCOR (metribuzin 75Vo),COMMAND (clomazone 367o), GOAL (oxyfluorfen 24Vo), and DUAL II MAGNUM (s-metolachlor/benoxacor)

OBJECTIVE: To evaluate alternative herbicide combinations with GESAGARD, LOROX, SENCOR andCOMMAND for weed control in carrots grown on muck soils.

METHODS: The trial was conducted at; site with organic soil (organic matter 75Vo,pH6.5) on the MuckCrops Research Station, Holland Marsh. Plots consisted of 2 hills, 86 cm apart and 4m long arranged in arandomized complete block design with four replications. One hill was seeded with cv. Pursuit (processingtype) and the other hill was seeded with Enterprise (fresh market type) at a population of 77 seed /m on 18May. The trial consisted of 16 treatments including a weedy control. Herbicide treatments consisted ofcombinations with preemergence treatments of LOROX at II25 galha, GESAGARD at 3400 gailha orCOMMAND at 28A or 560 gatlha followed by sequential applications of LOROX and/or SENCOR plusASSIST when carrots were at the I to 7 leaf stages of development. Additional treatments included GOALapplied postemergence and DUAL II MAGNUM applied preemergence and postemergence.Preemergence treatments were applied on 28 May and postemergence treatments applied on 15 June,22June, 6 July, and 20 July when carrots were at the 2, 3, 5 and 7 leaf stages, respectively. All treatmentswere applied in 200 Llba of water. Recommended management practices for soil fertility and pest controlwere followed. Visual assessments for crop injury and weed control were conducted periodically over thegrowing season. Carrots were harvested at maturity. Data was analyzed by ANOVA and means separatedusing Fisher's Protected LSD test (P=0.05).


CONCLUSIONS: Crop injury was minimal with all preemergence ffeatments including COMMAND at280 and 560 gailha applied alone or in tank-mixture with GESAGARD or LOROX. Similarly, croptolerance was excellent with postemergence treatments including treatments with DUAL II MAGNUM andGOAL and SENCOR + IVo Assist applied when carrots were at the 5 and 7 leaf stages (data not presented).LOROX and GESAGARD the standard preemergence treatments provided similar early season control ofredroot pigweed but control of common groundsel and hairy nightshade was greater with GESAGARD.COMMAND alone applied preemergence at 280 and 560 gailha provided excellent control of commongroundsel but was ineffective on redroot pigweed and hairy nightshade. A combination of COMMAND at280 gailha plus GESAGARD followed by a sequential application of LOROX when carrots were at the 3leaf stage provided excellent control of redroot pigweed, common groundsel and hairy nightshade.SENCOR plus l%o Assist applied when carrots were at the 5 and 7 leaf stage provided improved control ofredroot pigweed following preemergence combinations with GESAGARD, LOROX, and COMMAND.DUAL II MAGNIIM applied preemergence provided early season control of redroot pigweed and commongroundsel but not hairy nightshade. GOAL applied at 35 gar/ha when carrots were the 2 and 7 leaf stageswas ineffective on redroot pigweed. Carrot yields in the weedy control were approximately l}Vo of theyields obtained with the standard treatments. Greatest yields were obtained with treatments that providedearly season weed control. For example yields were generally reduced in treatments with COMMANDapplied alone preemergence compared to combinations with GESAGARD or LOROX because ofuncontrolled redroot pigweed and hairy nightshade early in the season but which were later controlled by

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postemergence treatments of LOROX. Further research should be conducted to evaluate preemergencecombinations with COMMAND.

Table 1. Herbicide combinations for weed control in carrots, MCRS, 2007.

Ti,-i^^ crop iniury' Redroot common Hairy

. Pigweed Groundsel Nightshade Yield

(Canot 15 26 15 26 15 26btagel Pursuit Enterprise Jun Jul Jun Jul Jun Jul Pursuit Enterprise

---- o/o

---- 7o control - Vha -

Treatment Dose(ga/ha)

Weedy 7.0 7.6

100 80.3 77.2DU408489B9PRE3 lea{ 0

LoroxLorox

1'125I tzJ

GesagardLOTOX

34001125

PRE3leaf 847193al91 100 74.0 75.5

CommandLorox

280't125

PRE2 leat 81 / Y-3

CommandLOTOX

5601125

PRE2leat 23tovo76 98 69.5 bv. /

Command +LoroxLorox

2801125I tz3

PREPRE3 leaf

8863TO9588B5 101 .3 89.6

Command +LoroxLorox

56011251125

PREPRE3 leaf

60 74.2 67.1

Command +GesagardLorox

28034001125

PREPRE3 leal

98qR9B 100 92.5 82.8

Command +GesagardLorox

56034001125

ooOR999895PREPRE O

3 leaf

r00 112.5 80.2

Gesagard 3400Lorox 1125Sencor + Assist 140+1"kSencor + Assist 140+1o/"

PRE3leaf5 leaf7 leat

10090

Command 560Lorox 1125Sencor + Assist 14Q+1"/"Sencor + Assist 140+1"/o

PRE3leaf5 leafI teal

89 67.0 47.5

CommandGoalGoal

q?PRE2lealI teal

58 20.6 17.2

Dual l l Magnum 1373Lorox 1125Sencor + Assist 14O + 1o/oSencor +Assist 140 + 17"

PRE3 leaf5 leal7 leat

101 .62585

Gesagard 3400Dual ll Magnum 1373Sencor +Assist 14O+1%Sencor + Assist 140+1 "zo

PRE5 leaf5 leal7 leat

946978 6B 86.6 67.7

Command 560Dual l l Magnum 1373Lorox 1125Sencor + Assist 140+1"/"Sencor + Assist 140+17"

PBEPRE3 leaf5 leaf7leal

10084 87.1 77.3

"/" Crop injury on June 1 5, 2007NS NS 10

95

22 25 22 32.4 22.1

Gesagard 3400Lorox 1125Dual ll Magnum 1373Sencor + Assist 140+17"Sencor + Assist 140+1"/"

PRE3 leaf5 leal5 leaf7 leal

94t'J 85 78.9 76.5

LSD (P=0.05) 11

-34-

CROP: Carrot (Daucus carota), cvs. Pursuit and Enterprise

AUTHORS: SWANTON CJ. JANSE S & CHANDLER K

TITLE:


AIM FOR DIRECTED POSTEMBRGBNCE BBTWEEN THB ROW WBEDCONTROL IN CARROTS. 2OO7

MATERIALS: AIM (carfentrazone22.4vo) and LOROX (linuron 50Vo).

OBJECTIVE: To evaluate AIM as a directed between row application for crop tolerance and weed controlin carrots grown on muck soils.

METHODS: The trial was conducted at a site with organic soil (organic matter 75Vo, pH 6.5) on the MuckCrops Research Station, Holland Marsh. Plots consisted of 2 hills, 86 cm apart and 4m long arranged in arandomized complete block design with four replications. One hill was seeded with cv.Pursuit (processingtype) and the other hill was seeded with Enterprise (fresh market type) at a population of 77 seed /m on 18May. The trial consisted of 4 treatments including a weedy control. Herbicide treatments consisted of AIMapplied at I7.5 and 26.3 gailha plus I 7o Assist in 300 L/ha directed between the crop rows with a non-shielded spay tip on 24 June when carrots were at the 4 leaf stage of development. A standard treatment ofLOROX applied broadcast at ll25 galha in 200 Llha at the 4 leaf stage was included for comparison. Alltreatments received a preemergence broadcast application of GESAGARD at 3400 gai/ha.Recommended management practices for soil fertility and pest control were followed. Visual assessmentsfor crop injury and weed control were conducted periodically over the growing season. Carrots wereharvested at maturity. Data was analyzed by ANOVA and means separated using Fisher's Protected LSDtest (P=0.05).


CONCLUSIONS: Crop injury was minimal with AIM treatments that were directed with a non-shieldedspray tip between the crop rows. AIM at 17.5 and 26.3 gailha provided good/excellent control 5 and 26DAT (days after treatment) of redroot pigweed, common groundsel and hairy nightshade. Weeds emergingsubsequent to the application of AIM were not controlled (data not presented) and reduced carrot yieldscompared to the standard broadcast treatment of LOROX. These results confirm the efficacy of AIM onimportant weeds in carrot production. AIM could be useful for the control of weeds including pigweedpopulations resistant to LOROX and GESAGARD. Spray shields or extreme caution is required for non-shielded spray application to prevent spray drift onto the crop.

Table 1. AIM for directed postemergence between the row weed control in carrots, MCRS, 2007.

Crop injury'Marketable Yield

29 20 29 20 29 20HUrSUrr Enrerpnse Jun Jul Jun Jul Jun Jul Hursurr trnrerpnse

Redroot Common HairyPioweed Groundsel NiohtshadeTreatment Dose Timing

(ga/ha) (CanotStage)

Weedy

Lorox 1'125 4leat 0 0 89 95

17.5 4leaf 1 3 95 85

26.3 4leat 3 3 98 96

NSNS67

000024.029.3

85 83 98 100 66.1 s9.3

BB 76 96 100 50.7 41.6

89 71 100 100 45.1 50.3

8 18 4 0 17.4 15.1

Aim +17"AssistAim +1%Assist

LSD (P=0-05)

"/o Crop injury on June 29,2007

-39-

CROP:PEST:

Celery (Apium graveolens L. var. dulce (Mil\er) Pers.), cvs. Florida 683 and Sabroso

Cercospora early blight (Cercospora apli Fresen)

AUTHORS: TESFAENDRIAS MTl, TRIJEMAN Ci, MCDONALD MR', GOSSEN BD,

TITLB:

MCKEOWN AW3 & VANDER KOOI K'rUniversity of Guelph, Dept of Plant Agriculture, Muck Crops Research Station2Agriculture and Agri-Food Canada, Saskatoon3University of Guelph, Dept of Plant Agriculture, Simcoe Research Station

NITROGEN AND CALCIUM AND THEIR INFLUENCE ON CBLBRY YIELDAND QUALITY,2ooT

MATERIALS: BRAVO 500 (chlorothalonil 50Vo), CALCITIM CHOLORIDE (calcium 367o),

AMMONIUM NITRATE (nitr o gen 3 4Vo)

MBTHODS: The trial was conducted on organic soil at 2 sites. Site 1, at the Muck Crops Research

Station (pH = 6.5, organic matter = 70Vo) and site 2 (off-station) near the Muck Crops Research station

(pH = 7.2, organic matter = 487o), Holland Marsh, Ontario. Celery seedlings were hand transplanted in

the field on 8 and 12 June in site 2 and l respectively, (three rows/ cultivar/ treatment) with in-row plant

spacing of 18 cm (Florida 683) and 22 cm (Sabroso). A randomized complete block arrangement with

four replicates per treatment was used. Each replicate consisted of 6 rows, 55 cm apart and 5 m in length.

All treatments were based on the recommended rates as set out by the OMAFRA recommendations

(nitrogen = 80 kg/ha preplant + 40kgha sidedress; calcium = 1.9 kg/ha). Treatments were: no nitrogen +

1007o calcium, 100Vo nitrogen + no calcium, 100 7o nitrogen + I007o calcium, 50Vo nitrogen + l00%o

calcium, l50%o nitrogen + I007o calcium, 200Vo nitrogen + l00Vo calcium, BRAVO 500 at 3'0 I./ha +

l007o nitrogen + I007o calcium. An untreated check (no nitrogen + no calcium) was also included. At the

MCRS (site 1), extra nitrogen fertilizer was inadvertently applied on all trial plots. This resulted in the

application of 667o of the recommended N rate, instead of 0 and 507oN as in site 2. Nitrogen ferlilizer was

applied preplant on 6 June and applied as a sidedress on 16 July. Calcium and fungicide treatments were

uppn"a bn t:, 23,30 July, 11, 27 August and 5 September using a pull type plot sprayer with TeeJet D-3

trbttow cone nozzles at 690 kPa (boom) in 500 L/ha of water. Early blight symptoms were first observed

on 4 July 2007 in both sites. Experimental plots were assessed and rated for early blight using a scale

from0-5, where: 0 =\Vo; I <27o;3 = 5-9Vo;4 = I0-247o;5 >25Vo fol iar are diseased perplot. These

values were used to calculate the area under disease progress curve (AIIDPC) using the following

equation:trj -:

AuDpc= I (tt*rtr* ') [r,. ,-t)i=r

Where 7 is the order index for the times and n; is the total number of assessments, y7 is the early blight

severiry rating at day t1, yi+tis the early blight severity rating at day \+t and (ti*t - t) is the number of days

between two assessments.

A sample of 12 plants was hand harvested from each replicate on 24,25 Sept (site 1), 26 and 28 Sept (site

2) and assessed for disease and yield parameters. Harvest weight and average height were recorded.

Sabroso was trimmed to 55 cm and Florida 683 to 40 cm and the trimmed weight was recorded. To obtain

marketable yield, diseased petioles were removed and plants were weighed.

After trimming, the leaves were assessed visually for early blight and rated on a scale from 0-5: 0 = ilo

lesions onleaves; l=<107o leavesdiseased;2=10-257o diseased;3=25-50Vo diseased;4=50-75Vo

diseased; 5 = >75Vo diseased. 120 outer stalks from the 12 harvested plants were removed and the petioles

were rated for early blight from 0-5: 0 = no disease; I = < l07o petiole area diseased;2 = I0-25Vo

-40-

diseased; 3 =25-50Vo diseased; 4 = 50-75Vo diseased; 5 =>75Vo diseased. The leafblight index (LBI) andpetiole diSease severity index (DSI) were determined using the following equations:

LBI = If(ratine class) (no. of plants in each rating class)l x 100(total number of plants rated) (no. classes - l)

DSI = Il(rating class) (no. of petioles in each rating class)l x 100(total number of petioles per sample) (no. classes - 1)

The air temperatures in 2007 were below the long term (10 year) average for July (I9.2"C), average forMay (I2.6"C), June (18.8"C), August (19.7"C) and September (L6.2"C) and above average for October(12.5'C). The long term (10 year) average temperatures were: May 12.5"C, June 18.3'C, July 20.2"C,August 19.1oC, September I5.7'C and October 9.loC. Monthly rainfall was below the long term (10year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm), September (40 mm) andOctober (32mm). The long term (10 year) rainfall averages were: May 80 mm, June77 mm, July 61 mm,August 57 mm, September 74 mm and October 56 mm. All data were analyzed using the GeneralAnalysis of Variance function of the Linear Models section of Statistix V.7. Means separation wasobtained using Fisher's Protected LSD test with P=0.05 level of significance.

RESULTS: \n2001, symptoms of celery late blight caused by Septoria apiicola developed late duringthe growing season and only on the artificially inoculated rows. The disease did not spread to theassessment rows. Symptoms of cercospora blight (early blight) due to natural infection by Cercosporaapii were first observed on 4 July 2007 in the experimental plots, before the treatments were applied. Insites I and 2, petiole disease severity, leaf blight severity and disease incidence were significantly lowerwith the BRAVO 500 + 1007o nitrogen + IO}Vo calcium treatment on both cultivars (tables I,3, 6 and 8).There were significant differences among treatments in LBI and leaf blight severity indicated by the areaunder disease progress curve (AUDPC). Both LBI and AUDPC were higher when no nitrogen wasapplied to both cultivars at site 2 (tables 6 and 8). The application of nitrogen resulted in a slightincremental increase in harvest weight, marketable yield and harvest height for both cultivars in site 2. Nosignificant effect of calcium application on yield, incidence and severity of early blight was observed onboth sites and cultivars.

In order to compare the effect of different rates of nitrogen on early blight and yield, the no calciumtreatments were removed from the analysis (Tables 3, 4, 8 and 9). Significant differences were observedbetween different rates of nitrogen application in petiole DSI for cultivar Sabroso at site 2. A similar trendwas noted with ATIDPC in both cultivars at site 2. Petiole DSI and AUDPC were lower with the BRAVO500 + 1007o N + 1007o Ca treatment followed by the 1507o N + I00Vo Ca treatment. The amount ofCercospora early blight (AUDPC) that developed over the season was higher on celery that received nonitrogen at site 2 (Table 8). Slight incremental increase in disease and reduction in yield was observedwhen the nitrogen application was increased to 200Eo of the recommended level. In both sites and for thetwo cultivars, haryest weight and marketable yield were significantly higher with the BRAVO 500 +1007o N + 1007o Ca treatment. The BRAVO treatment also had significantly higher plant height at site 2(Florida 683). Lower harvest weight and marketable yield were recorded in the no nitrogen treatment. TheI50Vo nitrogen treatments of cultivar Sabroso had no significant difference in harvest weight andmarketable yield from the BRAVO 500 + 1007o N + l00%o Ca treatment in site 1. It also had lowerATIDPC than the 66Vo N treatment. In site 2, the application of 1507c N + 700Vo Ca of the recommendedrate had higher harvest weight and marketable yield than the 07c N + 1007o Ca treatment on cultivarSabroso. Significant correlations (P S 0.01; r = 0.8) between nitrogen rate, harvest weight and marketableyield of celery cultivar Sabroso were observed in site 2 (Table l0). No symptoms of phytotoxicity wereobserved in anv treatments.

-4t-

CONCLUSIONS: Nitrogen and calcium did not adequately control early blight. However, for both

cultivars negative correlations between nitrogen rate and disease parameters (LBI, DSI and AUDPC)

were observed in both sites I and 2 although only the relationship between N rate and LBI for Florida 683

was significant. This indicated the role of nitrogen in reduction of early blight development during celery

growth. Thus, nitrogen may contribute to improve management practices in combination with fungicides

and other IPM practices.

Table 1.. Petiole disease severity index (DSI), foliar leaf blight rating, and AUDPC in two celery cultivars

(Florida 683 and Sabroso) treated with different rates of nitrogen, calcium and BRAVO fungicide for the

control of cercospora early blight, (Site 1), Muck Crops Research Station, Ontario, 2007.

Treatment (ToRecommended) Petiole DSI* Leaf Blieht Index AUDPC*

N' CaY BRAVOFlorida

6g3 JaDroso

Florida Florida6g3

JaDroso 683Sabroso

66

100

66

100

100

0

0

100

100

33.0 b" 44.7 b 42.5 ab 54.6b 173.0b l24.Ab

31.7 b 36.7 b 42.1ab 58.3 b 160.0 b 107.0 b

42.9 ab 53.8 b 173.0 b 133.0 b

44.6b 58.3 b 178.0 b 114.0 b26.9b 38.7 b

29.7 b 36.0 b

100 3.0L/ha 6.0 a 14.3 a 28.3 a 31.3 a 78.0 a 54.0 a

" Recommended nitrogen = 80 kdha preplant + 40 kg/ha sidedressY Recommended calcium = 1.9 kglha*DSI = Disease Severity Index* Area under the disease progress curveu Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's Protected

LSD test.

-42-

Table 2. Harvest weight, harvest height, marketable yield of two celery cultivars (Florida 683 andSabroso) treated with different rates of nitrogen, calcium and BRAVO fungicide for the control ofcercospora earty bltght, (Site l), ryluck Crops Research Station,earlv bli Site 1), Muck

TreatmentToRecommended

Harvest weieht Marketable vield

N' CaY BRAVO

(Florida

683 Sabroso Florida683

Sabroso Florida 683

Harvest height (cm)

Sabroso

660-

1000-

66 100

100 100

100 100 3.0Llha

0.67 b*

0.75 b

0,76b

0,67 b

1.23 a

1.08 b

r .29b1.34 ab

t.23b

1.64 a

0.36 b

0.43b

0.41b

0.39 b

0.93 a

0.46b

0.56 b

0.52b

0.50 b

0.86 a

49.38b

52.60 ab

50.78 b

49.88 b

59.86 a

60.80 b

65.13 b

64.48b

61.78 b

67.71 a"Recommended nitrogen = 8okg/ha@Y Recommended calcium = 1.9 ks/ha* Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's protectedLSD test.

Table 3. Petiole disease severity index (DSI), foliar leaf blight rating, and AUDPC in two celery cultivars(Florida 683 and Sabroso) treated with different rates of nitrogen, calcium and BRAVO fungiciie for thecontrol of cercospora early blight, (Site l), Muck Crops Research Station, Ontaio,2007.Treatment ( ToRecommended ) Petiole DSI* Leaf Blight Index AIIDPC*

N' CaY BRAVO Florida683 Sabroso Florida

683Sabroso Florida

683 Sabroso

66

100

150

200

100

100

100

100

100

100

26.9b"

29.7 b

28.8 b

30.7 b

6.0 a3.AUha

38.7 b 42.9 ab

36.0 b 44.6 ab

24.3 ab 40.0 ab

33.6 b 48.8 b

I4.3 a 283 a

173.0 b 133.0 b

178.0 b 114.0 b

184.0 b 103.0 b

167 .0 b 111.0 b

78.0 a 54.0 a

53.8 b

58.3 b

50.0 b

60.0 b

31.3 a" Recommended nitrogen = 80 k/@Y Recommended calcium = 1.9 ksy'ha^DSI = Disease Severity Index* Area under the disease progress curveu Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's protectedLSD test.

-43-

Table 4. Harvest weight, harvest height, marketable yield of two celery cultivars (Florida 683 andSabroso) treated with different rates of nitrogen, calcium, and Bravo fungicide for the control ofcercospora early blight, (Site 1), Muck Crops Research Station, Ontario, 2007.

Treatment Harvest weightHarvest height (cm)

(ToRecommended) (kg/plant)Marketable yield

(kg/plant)

N' cav BRAVo t:"#" Sabroso Florida683

FloridasaDroso

6g3Sabroso

66 100

100 100

150 100

200 100

100 100 3.0l-/ha

0.76 b*

0.67 b

0.69 b

0.74b

1.23 a

1.34 ab

r.23b

1.43 ab

1.19 b

I .64 a

0.41 b

0.39 b

0.38 b

0.44b

0.93 a

0.52b

0.50 b

0.67 ab

0.54 b

0.86 a

50.78 b

49.88 b

51.54 b

50.61 b

59.86 a

64.47 a

6L78 a

65.85 a

62.53 a

67.7I a

" Recommended nitrogen = 80 kg/ha preplant + 4Okg/ha sidedressY Recommended calcium = 1.9 kilha^ Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's ProtectedLSD test.

Table 5. Pearson linear correlation coefficient of cercospora early blight, N rate, and yield variables forcelery cvs, Florida 683 and Sabroso, (Site 1), Muck Crops Research Station, Ontario, 2007.

Weight (kg/plant)Height (cm)Cultivar N Rate

Weight Trimmed Marketable

Sabroso

DSI

LBI

ATIDPC

N Rate

DSI

LBI

AUDPC

N Rate

0.21'

0.59

0.03

-0.66

0.34

-0.70

-0.51

-0.13

-0.62

0.01

-0.79*

-0.41

-0.39

0.24

0.08

-0.46

-0.61

0.58

-0.76*

-0.41

-0.38

0.19

-0.54

-0.1l

-0.56

0.10

-0.94**

-0.27

-0.66

0.54

-0.45

-0.57

-0.39

-0.009

-0.67

-0.37

-0.27

0.14

Florida 683

Pearson correlation coefficient, *Significant at P < 0.05, **Significant at P < 0.01.Treatment BRAVO 500 + 80N + 40N+ l.9Ca was not included in the analysis to avoid declaration of falsesignificance related to fungicide effects.

-44-

Table 6. Petiole disease severity index (DSI), foliar leaf blight rating, and AUDPC in two celery cultivars(Florida 683 and Sabroso) treated with different rates of nitrogen, calcium, and Bravo fungicide for thecontrol of cercospora early blight, (Site 2), near Muck Crops Research Station, Ontario,2007 .Treatment (ToRecommended) petiole DSI* Leaf Blisht Index AUDpC*

N' cav BRAVo t?Iru" sabroso Florida sabroso Florida Sabroso

0 0 - 40.3 b" 4I.2b 51.7 bc 60.0 bc 198.0 c 106.0 bc

100 0 - 34.9b 46.5b 40.4b 47.5b 168.0b 95.0b

0 100 - 40.6b 46.6b 53.3 c 61.3 c 20L.0 c 138.0 c

100 100 - 35.2b 48.8 b 45.4bc 55.8 bc l79.0bc 88.0 b

100 100 3.OLlha 2.7 a L2 a 2O.4 a 20.8 a 60.0 a 30.0 a" Recommended nitrogen = 80 kg/ha preplant + 40kglha sidedressY Recommended calcium = 1.9 kg/ha'DSI = Disease Severity Index* Area under the disease progress curven Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's ProtectedLSD test.

Table 7. Harvest weight, trimmed weight, and harvest height of two celery cultivars (Florida 683 andSabroso) treated with different rates of nitrogen, calcium, and Bravo fungicide for the control ofcercospora early blight, (Site 2), near Muck Crops Research Station, Ontario, 2007.Treatment(ToRecommended)

Harvest weight(kg/plant)Marketableyield(kg)Harvestheight(cm)

N' cav BRAVo Xt#" Sabroso Florida Sabroso Florida sabroso

0 0 - 0.59 b* 0.97 b 0.35 b 0.43 b 42.90b 56.45b

100 0 - 0.70 b L22b 0.39 b 0.54 b 58.57 a 62.02 ab

0 100 - 0.62b 1.01 b 0.34 b 0.40 b 51.57 ab 56.87 b

100 100 - 0.69 b 1.35 b 0.39 b 0.56 b 52.50 ab 66.25 ab

100 100 3.0Uha l.2I a 1.85 a 0.95 a 1.53 a 62.33 a 72.05 a" Recommended nitrogen = 80 kg/ha preplant + 40 kgiha sidedressY Recommended calcium = 1.9 kg/ha'Numbers in a column followed bv the same number are not sienificantlv different at P = 0.05. Fisher's ProtectedLSD test

-45-

Table 8. Petiole disease severity index (DSI), foliar leaf blight rating, and AUDPC in two celery cultivars(Florida 683 and Sabroso) treated with different rates of nitrogen, calcium, and Bravo fungicide for thecontrol of cercospora early blight, (Site 2), near Muck Crops Research Station, Ontaio,2OO7.

Treatment (ToRecommended) Petiole DSI* Leaf Blisht Index AIIDPC*Florida

683SabrosoSabroso

Floriuda SabrosoBRAVO

FIOTidACaYN"

0

50

100

150

200

100

100

100

100

100

100

100 3.lLlha 2.1 b 7.2 a 20.4 a

40.6 a' 46.6bc 53.3 b

35.3 a 42.4bc 40.8 b

35.2 a 48.8c 45.4b

37.2 a 39.0 b 41.7 b

41.7 a 43.3bc 41.7 b

201.0 c 138.0 c

168.0 b 91.0 b

179.0 bc 88.0 b

159.0 b 77 .0 b

181.0 bc 100.0 b

60.0 a 30.0 a

61.3 b

52.9b

55.8 b

53.8 b

54.6b

20.8 aRecommended nitrogen = 80 kg/ha preplant + 40 kg/ha sidedress

Y Recommended calcium = 1.9 kglha^DSI = Disease Severity Index* Area under the disease progress curveu Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's ProtectedLSD test.

Table 9. Harvest weight, trimmed weight, and harvest height of two celery cultivars Florida 683 andSabroso) treated with different rates of nitrogen, calcium, and Bravo fungicide for the control ofcercospora early blieht, (Site 2), near Muck Crops Research Station, Ontario, 2007.Treatment Harvest weieht

Marketable yield (kg) Harvest height (cm)(ToRecommended) (kelplant)

N' CaY BRAVOFlorida

683Sabroso

Florida683

Florida683

Sabroso

0 100

50 100

100 100

150 100

200 100

100 100 3.0Llha l.2l a

56.87 c

62.50bc

65.25 ab

63.25 abc

62.81bc

72.05 aRecommended nitrogen = 80 kg/ha preplant + 40 kg/ha sidedress

Y Recommended calcium = 1.9 kg/ha* Numbers in a column followed by the same number are not significantly different at P = 0.05, Fisher's ProtectedLSD test.

0.62b*

0.68 b

0.69 b

0.71 b

0.65 b

1.01 c 0.34 b

I .22bc 0.41 b

1.35 bc 0.39 b

1.39 b 0.39 b

l .23bc 0.35 b

1.85 a 0.95 a

0.40 c

0.51bc

0.56 bc

0.59 b

0.56 bc

I .53 a

51.57 b

52.33b

52.50 b

52.76b

52.60b

62.35 a

--t6-

Table 10. Pearson linear correlation coefficient ofcercospora earlycelery cvs, Florida 683 and Sabroso, Holland-Bradford Marsh, ON,Research Station. Ontario. 2007.

blight, N rate, and yield variables for2007, (Site 2),near Muck Crops

Cultivar N RateWeight (kg/plant)

Harvest Trimmed MarketableHeight (cm)

Florida 683 DSI

LBI

AI'DPC

N rate

-0.02'

-0.741"-0.61

-0.76*

-0.78*

-0.87**0.58

-0.81*-0.70

-0.84**0.44

-0.94**-0.67

-0.81*0.16

-0.53

-0.67

-0.62

0.49

Sabroso DSI

LBI

AIJDPC

N rate

-0.14

-0.53

-0.59

-0.04-0.61

-0.82*0.76*

-0.03

-0.61

-0.81*0.73

-0.13

-0.69

-0.87*0.88**

0.19

-0.60

-0.76*o.7L

'Pearson correlation coefficient, *Significant at P < 0.05, **Significant at P < 0.01. Treatment BRAVO 500 + 80N+ 40N+ 1.9Ca was not included in the analysis to avoid declaration of false significance related to fungicide effects.

Funding for this project was supplied by A &L Labs Inc., London, ON, the OMAFRA,/University ofGuelph Sustainable Production Systems Program and by Canada and the Province of Ontariounder the Canada-Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-foodsector as a world leader. The Agricultural Adaptation Council administers the CORD program onbehalf of the province.

-47-

CROP:PEST:

Napa Cabbage (Brassica rapa ssp. pekinensis (Lour.) Hanelt) cv. YukiDowny Mildew (Personospora parasiticc (Pers.:Fr.) Fr.)

AUTHORS: MCDONALD MR & VANDER KOOI K

TITLB:


EVALUATION OF BRAVO ZN FOR CONTROL OF DOWNY MILDEWQERONOSPORA PARASITICA) ON NAPA CABBAGE.2AOT

MATERIALS: BRAVO 500 (chlorothalonil 507a), BRAVO ZN (chlorothalonil50To)

METHODS: The trial was conducted in organic soil (pH = 7.2, organic matter = 47.ZVo) near the MuckCrops Research Station, Holland Marsh, Ontario. On 4 June napa cabbage, cv. Yuki, was seeded into 128-cell Plastomer plug trays and hand transplanted on 29 June in three rows, 55 cm apart and 9 meter inlength, with an in-row spacing of 30 cm. A randomized complete block arrangement with four replicatesper treatment was used. Treatments were: BRAVO 500 at 3.0 Uha, and BRAVO ZN at 3.0 L/ha. Anuntreated check was also included. Treatments were applied on 1, 9, and 17 August using a CO2 backpacksprayer equipped with 4 TeeJet D-2 hollow cone nozzles spaced 40 cm apart and calibrated to deliver 250Llha at 240 hPa (boom). On 22 August, 12 heads in total were harvested from each experimental unit.Wrapper leaves were removed, downy mildew was assessed on a scale of 0 to 6 as follows: 0 = rodisease, l=1-2Vodiseased,2=3-57odiseased,3=6-L1Vodiseased,4=LI-207odiseased,5=21-307o diseased and 6 = >30Vo diseased, and trimmed head weights were recorded. The air temperatures in2007 were below the long term (10 year) average for July (I9.2"C), average for June (18.8'C), August(19.7'C) and September (16.2"C) and above average for October (12.5'C). The long term (10 year)average temperatures were: June 18.3"C, Jnly 20.2"C, and August 19.1'C. Monthly rainfall was belowthe long term (10 year) average for June (29 mm), July (27 mm), and August (33 mm). The long term (10year) rainfall averages were: June 77 mm, July 61 mm, and August 57 mm. Data were analyzed using theGeneral Analysis of Variance function of the Linear Models section of Statistix V.7. Means separationwas obtained using Fisher's Protected LSD test at P = 0.05 level of significance.


CONCLUSIONS: There were no significant differences among the treatments. Weather during July andAugust was dry; therefore disease pressurc in the trial was low. No phytotoxicity was observed aftertreatments were applied.

Table 1. Effectiveness of BRAVO 500 and BRAVO ZN for control of downy mildew (DM) on napacabbage grown near the Muck Crops Research Station, Holland Marsh, Ontario, 2007.

Treatment Rate (g ailha) # Leaves with DM/Plant Marketable Wgt/Head

BRAVO ZN

BRAVO 5OO

Check

1250

1250

9.0 ns

8.4

7.1

0.67 ns

0.62

0.65ns=no sisnificant differences were found between the treatments

Funding for this project was supplied by Syngenta Crop Protection, the OMAFRA/University ofGuelph Sustainable Production Systems Program.

-50-

CROPS: Flowering Cabbage (Brassica oleracea L.)Pak Choy (Brassica ropa var. chinensis)

PBST: Clubroot (Plasmodiophora brassicae Woronin)

AUTHORS: MCDONALD MRI, VANDER KOOI Kl, GOSSEN BD2 & WESTERVELD SM3tuniversity of Guelph, Dept. of Plant Agriculture, Muck Crops Research StationzAsriculture and Aeri-Food Canada. Saskatoon

'Uiiversity of Gueiph, Dept. of Plant Agriculture, Simcoe Research Station

TITLE: EFFECT OF SEEDING DATB AND HARVEST INTERVALS ON THEDEVELOPMENT OF CLUBROOT ON ASIAN VBGETABLES, 2OO7

METHODS: The trial was conducted at the Muck Crops Research Station, Holland Marsh, Ontario, onorganic soil (pH x 6.'7, organic matter = 68.9Vo) naturally infested with Plasmodiophora brassicae.Flowering cabbage and pak choi were direct seeded (34 seeds/m) on 11 May,7 June,5 July, 13 and 30August using a Stan Hay precision seeder. Treatments wege replicated four times in a randomizedcomplete block design. Each replicate consisted of 2 rows, 5.5 m in length for both flowering cabbageand pak choy. At 27 days after seeding (DAS) and weekly for 3 or 4 weeks, 1 m of plant row was dugand the roots examined and rated for clubroot using a scale from 0-3: 0 = no clubbing, 1 <25Vo of rootsystem clubbed, 2 = 25-50Vo of root system clubbed, 3 >507o of root system clubbed. The diseaseseverity index (DSI) was calculated using the following equation:

n6Y -- . ^^DSI = (total no. plants per sample)(no. classes -1) x 100

The air temperatures in 2007 were below the long term (10 year) average for July (I9.2"C), average forMay (I2.6"C), June (18.8'C), August (19.7"C) and September (I6.2"C) and above average for October(12.5"C). The long term (10 year) average temperatures were: May 12.5"C, June 18.3'C, July 20.2"C.August 19.1"C, September 15.7"C and October 9.1'C. Monthly rainfall was below the long term (10year) average for May (43 mm), Iune (29 mm), July (27 mm), August (33 mm), September (40 mm) andOctober (32 mm). The long term (10 year) rainfall averages were: May 80 mm, JuneJT mm, July 61 mm,August 57 mm, September 74 mm and October 56 mm. Data were analyzed using the General Analysisof Variance function of the Linear Models section of Statistix V.7. Means separation was obtained usingFisher's Protected LSD test at P = 0.05 level of sisnificance.

RESULTS: As presented in Tables 1 and 2

CONCLUSIONS: Significant differences in disease severity index (DSI) and incidence were foundamong the seeding dates and the various harvest intervals in Shanghai pak choy. DSI and clubrootincidence increased as the plants matured. Significant increases in DSI and incidence were foundbetween 2'7 and 34 days after seeding (DAS) at all planting dates except in July. The July seeding datehad a significant increase in DSI and incidence between 2O and 27 DAS. Similar results were found inthe flowering cabbage, however, disease severity and incidence was higher in the Shanghai pak choy.Results indicate that clubroot develops close to harvest in these crops. Disease incidence also decreasedthroughout the growing season. Trials planted in August had the lowest overall incidence and severity ofthe five seeding dates

Funding for this project was provided by the OMAFRAruniversity of Guelph SustainableProduction Systems Program.

-5 l -

Table 1. Effect of seeding date on the incidence and severity ofclubroot in Shanghai pak choy, grown at

the Muck Crops Research Station, 2007.

Seeding DateHarvestIntervalDAS'

11May 7 June 5 July 2 August 30 August

DSI2 VO CR DSI VO CR DSI VO CR DSI VO CR DSI VO CR

taIJ

20

27

3.1

40

l1+t

0.0 a3 0.0 a

0.4 a I .2 a

2r.6b 42.8b

52.9 c 63.9b

0.0 a 0.0 a

7 .0 a 20.1b

39J b 83.1 c

0.0 a 0.0 a

1.5 a 4.4 a

46.6b 68.6 b

52.2b 68.8 b

0.0 a 0.0 a

0.0 a 0.0 a

0.0 a 0.0 a

3.1b 9.2b

0.0 a 0.0 a

0.0 a 0.0 a

0.0 a 0.0 a

5.3 b 14.7 b

' DAS= Days after seedingt Dis.use severity index (DSI) was determined using the following equation:

Or, _ ,e l(class no.Xno. of plants in each class)]

" ,OO

(total no. plants per sample)(no. classes -l): \umbers in a column followed by a different letter are significantly different at P=0.05, Fisher's Protected LSD test.

Table 2.Effect of seeding date on the incidence and severity of clubroot in flowering cabbage, grown at

the Muck Crops Research Station, 2007.

Harvest Seeding Date

IntervalDAS'

l.l May 7 June 5 July 2 August 30 August

DSI2 VO CR DSI VO CR DSI VO CR DSI VO CR DSI VO CR

t3

20

27

34

40

47

0.0 a3 0.0 a

0.0 a 0.0a

1.4 a 4.3 ab

6.1b 10.6 b

0.3 a 0.8 a

3.5 ab 7.9 ab

6.6 b 14.0 b

0.0 a 0.0 a

0.0 a 0.0 a

24.4b 42.7 b

29.7 b 48.0 b

0.0 a 0.0 a

0.0 a 0.0 a

0a 0.0a

8.2 b 20.r b

0.0 a 0.0 a

0.0 a 0.0 a

0.0 a 0.0 a

0.5 b 1.3 b

t DAs= Days after seeding

'Dir"ur" severity index (DSI) was determined using the following equation:

e [(class no.)(no. ofplants in each class)]u'JI- ^

rvv

(total no. plants per sample)(no. classes -l)

3 Numbers in a column followed by a different letter are significantly different at P=0.05, Fisher's Protected LSD test

-56-

CROP:PBSTS:

AUTHORS:

TITLE:

Cauliflower (Brassica oleracea var. botrytis) cv. ApexDowny Mildew (Personospora parasiticc (Pers.:Fr.) Fr.Alternaria leaf blight (Alte rnar i a b r as s ic i c ol a (Schwein. ) Wiltshire)


EVALUATION OF REVUS FOR CONTROL OF DOWNY MILDEW(P E RO N O S P O RA P A RA S IT I CA) ON CAULIFLOWER, 2OO7

MATERIALS: REVUS 250 SC (mandiproparnd23.3Vo), BRAVO 500 (chlorothalonil 50Vo),BRAVO ZN (chlorothalonil 50Vo), SYLGARD 309 (polysiloxaneSOVo)

METHODS: The trial was conducted in organic soil (pH = 7.2, organic matter = 47 .ZVo) near the MuckCrops Research Station, Holland Marsh, Ontario. On 4 June cauliflower, variety Apex, was seeded into128-cell Plastomer plug trays and hand transplanted on 29 June in two rows, 86 cm apart and 9 meter inlength, with an in-row spacing of 45 cm. A randomized complete block arrangement with four replicatesper treatment was used. Treatments were: REVUS at 200,400, and 600 ml/ha, REVUS + SYLGARD at400 ml/ha + 0.25Vo and 600 ml/ha + 0.257o, BRAVO 500 at 2.5 Llha, BRAVO 500 + REVUS at 2.5L/ha + 400 ml*/ha, BRAVO 500 + REVUS + SYLGARD at 2.5 Uha + 400 ml/ha + 0.25Vo, BRAVO ZNat 2.5 Uha and BRAVO ZN + REVUS at 2.5 Llha + 400 mllha. An untreated check was also included.Treatments were applied on 9, and24 August and 6 September using aCOz backpack sprayer equippedwith 4 TeeJet D-2 hollow cone nozzles spaced 40 cm apart and calibrated to deliver 250 Uha at 240 kPa(boom). On 16 August the plot was inoculated with 30,000 spores/ml of Alternaria brassicicola in0.0IVo Tween 80 solution at the rate of 250 L/ha. This was immediately followed by irrigation to achieveleaf wetness. On 14, 18 and 21 September as heads matured, 15 heads in total were harvested from eachexperimental unit. Wrapper leaves were removed, alternaria lesions were counted and downy mildew(DM) was assessed on a scale of 0 to 6 as follows: 0 = no disease, 1 = 1 - ZVo diseased, 2 = 3 - 5Vodiseased,3=6-107odiseased,4=11-20Vodiseased,5=21*30Todiseasedand6=>307odiseased,healthy leaves were counted and trimmed head weights were recorded. The DM disease severity index(DSI) was calculated using the following equation:

DSI = I [(class no.Xno. of leaves in each class)] x 100(total no. leaves per sample)(no. classes - 1)

The air temperatures in 2007 were below the long term (10 year) average for July (I9.2"C), average forJune (18.8'C), August (19.7'C) and September (16.2'C) and above average for October (12.5'C). Thelong term (10 year) average temperatures were: June 18.3oC, }uly 20.2"C, August 19.1"C, September15.l"C and October 9.1'C. Monthly rainfall was below the long term (10 year) average for June (29 mm),htly (27 mm), August (33 mm), September (40 mm) and October (32 mm). The long term (10 year)rainfall averages were: June 77 mm, July 61 mm, August 57 mm, September 74 mm and October 56 mm.Data were analyzed using the General Analysis of Variance function of the Linear Models section ofStatistix V.7. Means separation was obtained using Fisher's Protected LSD test at P = 0.05 level ofsignificance.


CONCLUSIONS: There were significant differences among the treatments for alternaria lesions per leafat harvest (Tablel). Cauliflower treated with the standard rate of REVUS + BRAVO 500 + Sylgard hadsignificantly fewer alternaria lesions per leaf than the low and standard rates of REVUS, the high rate ofREVUS + Sylgard, and the check. Cauliflower treated with BRAVO 500, BRAVO ZN or combinationscontaining either BRAVO 500 or BRAVO ZN had fewer alternaria lesions than cauliflower treated withREVUS at standard and low rate and the untreated check. There were no significant differences in DM

-57-

severity, percent leaves with DM or the average weight per head among the treabxents. No phytotoxicitywas observed among the treatrnents.

Table l. Effectiveness of REVUS for control of alternaria and downy mildew @M) on cauliflowergrown at the Muck Crops Research Station, Holland Marsh, Ontario,2007.

Treatment Rate(g ailha)# Arternaria ^

DY vo!*aves

Average

*,r,,.'nHr tffilr ;i,#M wffiaaREVUS + BRAVO 5OO +SYLGARD

BRAVO AN

REVUS + BRAVO 500

REVUS + BRAVO Z}.{

BRAVO 5OO

REVUS + SYLGARD

REVUS

REVUS + SYLGARD

REWS

Check

REVUS

lffi+1250+0.25Vo

1250

100+1250

100+1250

1250

l00,+O.257o

150

fi0+4.25%

lm

0.6 ar

0.8 ab

0.8 ab

0.8 ab

0.8 ab

1.0 abc

1.1 bcd

2.8 ns2 lo.5 ns

13.8

19.9

12.3

1.3 ns

t .2

1.3

1.3

1.3

t .3

1.4

3.5

5.3

0.8 ab 3.4

3.8 13.6

4.1

5.8

3.4

2r.o

15.6

15.4 1.3

18.4 t .2

13.3 1.3

16.5 1.41.3 cd 4.3

1.4 de 8.1

50 1.7 e 4.1

ificintly different at P=0.05, Fisher's Protected LSDtest.2 ns = no signific4nt differences were found among the treatrnents3DM severity Rating = x 100

(total no. leaves per sampleXno. classes - 1)

Funding for this project was supplied by Syngenta Crop Protection Inc., Guelph' ON and theOMAFRA lniversity of Guelph Sustainable Production Systems Program.

-64-

CROP:PESTS:

AUTHORS:

Yellow cooking onions (Allium cepaL.) cv. MillenniumOnion smut, (Urocystis colchici var. cepulae Cooke)Onion maggot, (Delia antiqua (Meigen))

MCDONALD MRI, VANDER KOOI KI & TAYLOR AG2I University of Guelph, Dept. of Plant Agriculture, Muck Crops Research Station' Cornell University, Dept. of Horticultural Science, New York State AgriculturalExperiment Station

EVALUATION OF VARIOUS SEED TREATMENTS FOR CONTROL OF ONIONMAGGOT AND ONION SMUT IN YELLOW COOKING ONIONS,2OO7

TITLE:

MATERIALS: RAXIL (tebuconazole28.47o), THIRAM (thiram 42Vo),L-1491-A (clothianadin)

METHODS: A selected new seed treatment for yellow cooking onions was evaluated in a field trial onorganic soil (pH = 6.6, organic matter = 45.3Vo) naturally infested with Urocystis colchici and Deliaantiqua pupae near the Muck Crops Research Station, Holland Marsh, Ontario. Treatments were: RAXILat250 mg ai + THIRAM at 188 mg ai + L-1491-A at 4880 mg ai, and THIRAM at 188 mg ai as a check.All seed treatments are mg ail100 g seed. Treatments were replicated four times in a randomized completeblock design. Each replicate consisted of 4 rows (42 cm apart), 6 m in length. All seed treatments wereseeded on 7 May using a push-cone seeder. Six random 2.m sections were staked out, and germinationcounts were conducted on a weekly basis to determine initial stands prior to first generation assessment.At one (8 June) and three (25 June) true leaves, one of the 2m sections was harvested and bulbs and leaveswere visually evaluated for onion smut (OS). The remaining 2 m section was evaluated in the samemanner when plants reached maturity (27 August). Plants were examined for onion maggot (OM) ordamage caused by other pests within the staked-out sections on a weekly basis throughout June and July.Damaged plants were rogued out and the cause recorded. Damage was recorded two weeks after the endof the first (6 July) and second (13 August) generation peaks and at harvest (20 September) (onion bulbmaturity). On 4 October a 2.33 m section was harvested and weighed to determine yield. The airtemperatures in 2007 were below the long term (10 year) average for July (L9.2"C), and average for May(12.6"C), June (IB.B'C), August (19.7'C) and September (I6.2"C. The long term (10 year) averagetemperatures were: May 12.5'C, June 18.3'C, IuJy 2A.2"C, August 19.1'C, and September 15.7'C.Monthly rainfall was below the long term (10 year) average for May (43 mm), June (29 mm), July (27mm), August (33 mm), and September (40 mm). The long term (10 year) rainfall averages were: May 80mm, June JJ mm, July 61 mm, August 57 mm, and September 74 mm. Data were analyzed using theGeneral Analysis of Variance function of the Linear Models section of Statistics V.7. Mean separationwas obtained using Fisher's Protected LSD test with P =0.05 level of significance.

RESULTS: As presented in Tables L and2

CONCLUSIONS: Significant differences in 1" generation and total season onion maggot losses werefound among the treatments. Onions grown from seed treated with RAXIL +L-1497-A had significantlyfewer OM losses than onions grown from seed treated with THIRAM only (Table 1). There was a lowonion smut infestation rate at this site and no significant differences in onion smut losses or yield amongthe treatments (Table 2).

-65-

Table L. Evaluation of a seed fteatment for the control of onion maggot in yellow cooking onions (Allium

cepa) near the Muck Crops Research Station, Holland Marsh, Ontario, 2007.

, Rate Product (mg Vo Onion Maggot Losses-l reatments' Yield (t/ha)

ail100 g seed) l.tGeneration Total

Th + R + L 188 +250 + 4880 1.3 a2 8.1 a 34.2ns3

Th 188 58.0 b 29.2b 2s.2' Th = THIRAM, R = RAXIL,L =L -1491-A (chlothianidin)2 Numbers in a column followed by a different letter are significantly different at P = 0.05, Fisher's Protected LSD

test.3 ns = no significant differences were found among the treatrnents

Table 2. Evaluation of seed treatments and for the control of onion smut in yellow cooking onions (AIIium

cepa) near the Muck Crops Research Station, Holland Marsh, Ontario, 2007.

Vo Onion Smut Losses

1" Leaf 3'd Leaf Total

Th +R + L 188 + 250 + 4880 1.8 nsz 0 0 ns

Th 188 4.9 0.6 r.2Th= THIRAM, R = RAXIL,L =L -1491-A (chlothianidin)

2 ns = no significant differences were found among the treatments

Funding for this project was supplied by the OMAFRAruniversity of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under the Canada-Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-food sector as aworld leader.

, Rate Product (mgTreatments'

aill00 g seed)

-66-

CROP:PEST:

Yellow cooking onions (Allium cepaL.)Onion maggot, (Delia antiqua (Meigen))


TITLE:


FIELD EVALUATION OF COMMBRCIAL YBLLOW COOKING ONIONCULTIVARS INTERPLANTBD WITH ONIONS TREATED WITHINSECTICIDE FOR RBSISTANCE TO THE OMON MAGGOT. DELIAANTIQUA (MEIGEN),2007

MATERIALS: 5 commercial cultivars (4 untreated and 1 treated) from various seed companies

MBTHODS: Onions of cultivars Cortland (Bejo Seeds Inc.), Hoopla (Solar Seeds), Fortress (StokesSeeds Inc.), and Millennium (Nunhems), were evaluated for their resistance to the onion maggot (OM) intwo field trials where Delia antiqr?c occurs naturally, at site 1, Muck Crops Research Station on organicsoil (pH = 6.6, organic matter = 70.27o) and site Z (pH = 6.7, organic matter = 55.2Vo), Holland Marsh,Ontario. Four onion cultivars were direct seeded at 34 seeds/m on 4 May using a Stan Hay Precisionseeder. Each cultivar was replicated four times in a randomized complete block design. Each replicate ofthe 4 experimental units consisted of 4 rows (40 cm apart), 5 m in length interplanted with cultivarHamlet (Seminis) at Site 1 and Saffrane (Bejo Seeds Inc.) at Site 2,treated with the insecticide Governorand seeded into 4-row beds, 13 m in length to establish a buffer between the untreated onion cultivars. Alltreatments received an in furrow treatment of DITFIANE DG at 8.8 kg/ha to provide onion smut control.Recommended control procedures to manage other insects, pathogens and weeds were followed. A 2 msection for each of 3 OM assessments were randomly selected and staked out within each block. Todetermine initial stand count, plant emergence was determined. Plants were visually examined weekly foronion maggot or damage caused by other pests within the 2 m staked-out sections throughout June andJuly. Damaged plants were rogued out and the cause recorded. Onion damage was recorded two weeksafter the end of the first (4 July) and second (13 August) generation peaks and at onion bulb maturity on13 (Site 2) and 20 September (Site 1). Total damage was calculated as the cumulative damage caused bythe first and second generation of maggots and the damage recorded at harvest. On 10 September a Z.3Zyield section was harvested and on 4 October onions were assessed and weights and numbers of healthybulbs were recorded. The air temperatures in 2007 were below the long term (10 year) average for July(19.2"C), and average for May (12.6"C), June (18.8"C), August (19.7'C) and September (16.2'C. Thelong term (10 year) average temperatures were: May 12.5'C, June 18.3'C, Jliry 20.2"C, August 19.1'C,and September 15.7oC. Monthly rainfall was below the long term (10 year) average for May (43 mm),June (29 mm), July (27 mm), August (33 mm), and September (40 mm). The long term (10 year) rainfallaverages were: May 80 mm, June 77 mm, July 6l mm, August 57 mm, and September 74 mm. Data wereanalyzed using the General Analysis of Variance function of the Linear Models section of Statistics V.7.Means separation was obtained using Fisher's Protected LSD test at P=0.05 level of significance.

RESULTS: As presented in Tables I andZ

CONCLUSIONS: There were significant differences in total OM losses among the treatments at site 1.Onions grown from insecticide-treated seed had significantly lower OM losses than untreated Hoopla andMillennium, but not significantly lower OM losses than untreated Cortland and Fortress (Table 1). Therewere no significant differences in OM damage at site 2 and total OM damage was low, averaging l0.5Voin onions grown from untreated seed compared with 07o losses in the onions grown from treated seed(Table 2). Significant differences in yield at site I were found among the treatments. Onions grown fromtreated seed had significantly higher yield than Hoopla and Millennium grown from untreated seed. The

-6'/-

weight per bulb of Hoopla was significantly higher than all other onions probably because Hoopla is

phenotypically a larger onion.

Table l. Percent onion maggot (OM) damage and yield of onion varieties interplanted within onions

treated with insecticide at site 1, Muck Crops Research Station, Holland Marsh, Ontario, 2007.

Vo OM Losses Yield

Cultivar Weieht/bulb(g)1" Gen Total

Treated Checkr

Cortland

Fortress

Hoopla

Millennium

10.0 nsr

rg.3

30.4

40.8

37.0

I3.5 a3

23.9 ab

24.4 ab

46.0 b

48.5 b

146.6b 82.2 ab

I7l .2b 92.7 a

157.6b 63.6bc

289.8 a 6I.4 c

196.8 b 51.5 ct Variety Hamlet treated with Governor2 ns indicates no significant differences found among the treatments3 Numbers in a column followed by a different letter are significantly

test.

different at P = 0.05. Fisher's Protected LSD

Table 2. Percent onion maggot (OM) damage and yield of onion varieties interplanted within onions

treated with insecticide at site 2, Holland Marsh, Oritario, 2007'

7o OM Losses Yield

Cultivar Weight/bulb(e)1tt Gen Total t/ha

Treated Checkr

Hoopla

Fortress

Cortland

Millennium

3.6 ns

r 1.9

t6.4

9.1

2t.2

0ns

12.5

4.9

4.6

20.1

163.5 b3

267.7 a

l39.2bc

127.4 c

152.6bc

97.4 ns

9t.7

70.4

75.r

72.2

Variety Saffrane treated with Governor2 ns indicates no significant differences found among the treatments3 Numbers in a column followed by a different letter are significantly different at P = 0.05, Fisher's Protected LSD

test.

Funding tbr this project was supplied by the OMAFRAruniversity of Guelph Sustainable

Produciion Systems Program and by Canada and the Province of Ontario under the Canada-

Ontario Research & Development (CORD) program, an initiative of the federal-provincial-

territorial Agricultural Policy framework designed to position Canada's agri'food sector as a world

leader. The Agricultural Adaptation Council administers the CORD program on trehalf of the

province,

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CROP:PEST:

Yellow cooking onions (Allium cepaL.) cv. HamletDowny Mildew (Peronospora destructor Berk. Casp. In Berk)


TITLE:


COMPARISON OF VARIOUS OMON VARIETIES FOR RESISTANCE TODOWNY MILDEW QERONOSPORA DESTRACTOR\ IN ONIONS.2OOT

MATERIALS: 8 onion cultivars from various seed companies

METHODS: Onions of cultivars Tahoe, (Bejo Seeds Inc.), Hamlet, Ricochet, Fortress, Mars (StokesSeeds), Nebula (Nunhems) and Stanley (Solar Seeds Inc) were direct seeded (34 seeds/m) using a StanHay Precision seeder and raw seed of numbered cultivar BGS 236 (Bejo Seeds Inc.) was planted using apush V-belt seeder, on 9 May, into organic soil (organic matter = 48.0Vo, pH = 7.0) near the Muck CropsResearch Station, Holland Marsh, Ontario. A randomized complete block arangement with fourreplicates per treatment was used. Each replicate consisted of four rows, 42 cm apart, 5 m in length.Recommended control procedures for weeds and insects were followed. On 2I and 31 August, 25 and 20plants respectively per replicate were harvested and the number of downy mildew (DM) lesions werecounted and recorded. On 13 September a 4.64 m yield sample was taken from each replicate and theonions were weighed and graded for size on 23 October. The air temperatures in 2007 were below thelong term (10 year) average for July (I9.Z"C), and average for May (I2.6"C), June (18.8'C), August(19.7"C) and September (I6.2"C. The long term (10 year) average temperatures were: May I2.5"C, June18.3'C, July 20.2"C, August 19.1'C, and September 15.J'C. Monthly rainfall was below the long term(10 year) average for May (43 mm), June (29 mm), July (27 mm), August (33 mm), and September (40mm). The long term (10 year) rainfall averages were: May 80 mm, June77 mm, July 61 mm, August 57mm, and September 74 mm. Data were analyzed using the General Analysis of Variance function of theLinear Models section of Statistix V.7. Means separation was obtained by using Fisher's Protected LSDtest at P = 0.05 level of sisnificance.


CONCLUSIONS: No significant differences were found among the cultivars in DM lesions per plant,yield and percent marketable. However, cultivar BGS 236 had the fewer DM lesions numerically perplant than the other cultivars. There were no significant differences in yield or percent marketable amongthe cultivars. The dry weather during August was not favourable for the development of downy mildew.

-69-

Table l. The incidence of downy mildew and yield of various onion varieties grown at the Muck Crops

Research Station, Holland Marsh, Ontaio, 2007 .

VarietyDowny MildewLesions/plant

2l August

Downy MildewLesions/plant

31 August

Marketable Yield(t/ha) VoMarketable

BGS 236

Stanley

Fortress

Hamlet

Tahoe

Ricochet

Mars

Nebula

0.1 ns

0.1

0.7

0.2

0.0

0.0

0.0

0.2

1.2 ns

2.3

2.4

2.9

2.9

3.1

3.4

3.5

36.5 ns

54.3

45.0

52.2

59.7

53.r

44.0

63.7

81.9 ns

90.8

84.7

88.0

92.8

92.7

82.9

94.8r Numbers in a column followed by the same letter are not significantly different at P = 0.05, Fisher's Protected LSD

test.

Funding for this project was supplied by the OMAFRAAlniversity of Guelph SustainableProduction Systems Program and by Canada and the Province of Ontario under the Canada-

Ontario Research & Development (CORD) program, an initiative of the federal-provincial-territorial Agricultural Policy Framework designed to position Canada's agri-food sector as arvorld leader. The Agricultural Adaptation council administers the CORD program on behalf of theprovince.

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CROP:PEST:

Yellow cooking onions (Allium cepaL.) cv. HamletBotrytis leaf blight (Botrytis squamosa J.C. Walker)


TITLE:


EFFICACY OF BRAVO ZN FOR THE CONTROL OF BOTRYTIS LEAFBLIGHT ON ONIONS.2OOT

MATERIALS: BRAVO 500 (chlorothalonil 50Vo), BRAVO ZN (chlorothalonil50%)

METHODS: Onions, cv. Hamlet, were direct seeded (34 seeds/m) on 5 May using a Stan Hay Precisionseeder, into organic soil (organic matter = J2.6Vo, pH: 6.5) at the Muck Crops Research Station, HollandMarsh, Ontario. A randomized complete block arrangement with four replicates per treatment was used.Each replicate consisted of eight rows (42 cm apart), 5 m in length. Treatments were applied on 21,28July and 11, 18 August using a pull type plot sprayer with TeeJet D-2 hollow cone nozzles at 690 kPa(boom) in 500 L/ha of water. Treatments were: BRAVO 500 at 2.4 L/ha, BRAVO ZN at 2.4 Llha.Twenty five plants per replicate were harvested on 22 August when the plants were near maturity. Thethree oldest green leaves per plant with 807o or more of non-necrotic tissue were evaluated for botrytisleaf blight. The percentage of green tissue area infected was rated using The Manual of Assessment Keysfor Plant Diseases by Clive James, Key No. 1.6.1. The total number of green and dead leaves was alsorecorded. A 4.64 m yield sample was taken from each replicate on 6 September for yield assessments.The onions were weighed and graded for size on 9 October. The air temperatures in 2007 were below thelong term (10 year) average for July (19.2"C), average for May (I2.6"C), June (18.8"C), August (I9.7"C>and September (16.2'C) and above average for October (12.5"C). The long term (10 year) averagetemperatures were: May 12.5'C, June 18.3'C, July 20.2"C, August 19.1oC, September 15.7"C andOctober 9.1'C. Monthly rainfall was below the long term (10 year) average for May (43 mm), June (29mm), July (27 mm), August (33 mm), September (a0 mm) and October (32 mm). The long term (10 year)rainfall averages were; May 80 mm, ltne J7 mm, July 61 mm, August 57 mm, September 74 mm andOctober 56 mm. Data were analyzed using the General Analysis of Variance function of the LinearModels section of Statistix V.7. Means separation was obtained by using Fisher's Protected LSD test atP= 0.05 level of significance.


CONCLUSIONS: No significant differences were found among the treatments in DSI, the number ofgreen and dead leaves and yield. Disease pressure was low due to the hot, dry weather during the growingseason. No phytotoxicity was observed after any treatments.

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' Table 1. Effectiveness of BRAVO 500 and BRAVO Z.{ for confrol of botrytis leaf blight on onionsgrown at the Muck Crops Research Station, Holland Marsh, Ontario, 2007.

rrearment .-llf-., off; u

"'ff; u

,""*T,Ti*. yierd (t/rra)G "/hu) r.uu"vpt*tt I-"uuolptuot (osb'J

BRAVO 500 l2W 7.9 ns2 2.8 ns 15.0 ns 75.0 nsBRAVO An

'200 7.3 2.8

Check 7. t 3.116.3 7r.O18.2 74.8

' Average of all green leaves on 25 plants/treatment2ns= no significant differences were found between the treatments

'DSI= " t*

o 75 leaves per rcplicate were graded for % botytts leaf blight

Fundlng for this project was zupplled by Syngenta Crop Protection Inc., Guelph, ON and theOMAFRA/University of Guelph Susrainable Production Systems Program.

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CROP:PEST:

Yellow cooking onions (Allium cepaL.) cv. HamletBotrytis leaf blight (Botrytis squamosa J.C. Walker)


TITLE:


EFFICACY OF SERENADE FOR THE CONTROL OF BOTRYTIS LEAFBLIGHT ON ONIONS,2OO7

MATBRIALS: SERENADE ASO (Bacillus subtilis (QST 713 Strain))

MBTHODS: Onions, cv. Hamlet, were direct seeded (34 seeds/m) on 5 May using a Stan Hay Precisionseeder into organic soil (organic matter = 72.6Vo, pH = 6.5) at the Muck Crops Research Station, HollandMarsh, Ontario. A randomized complete block arrangement with four replicates per treatment was used.Each replicate consisted of eight rows (42 cm apart),5 m in length. Treatments were appliedon2l,2SJuly and 11, 18 August using a pull type plot sprayer with TeeJet D-2 hollow cone nozzles at 690 kPa(boom) in 500 Llha of water. Treatments were: BRAVO 500 at 2.4 L/ha, BRAVO ZN at 2.4 Llha.Twenty five plants per replicate were harvested on 22 August when the plants were near matudty. Thethree oldest green leaves per plant with 807o or more of non-necrotic tissue were evaluated for botrytisleaf blight. The percentage of green tissue area infected was rated using The Manual of Assessment Keysfor Plant Diseases by Clive James, Key No. 1.6.i. The total number of green and dead leaves was alsorecorded. A 4.64 m yield sample was taken from each replicate on 6 September for yield assessments.The onions were weighed and graded for size on 9 October. The air temperatures in 20O7 were below thelong term (10 year) average for July (I9.2'C), average for May (L2.6"C), June (18.8"C), August (19.7"C)and September (16.2'C) and above average for October (12.5'C). The long term (10 year) averagetemperatures were: May 12.5"C, June 18.3oC, Iuly 2A.2"C, August 19.1"C, September 15.7"C andOctober 9.1"C. Monthly rainfall was below the long term (10 year) average for May (43 mm), June (29mm), July (27 mm), August (33 mm), September (40 mm) and October (32 mm). The long term (10 year)rainfall averages were: May 80 mm, Jtne 77 mm, July 61 mm, August 57 mm, September 74 mm andOctober 56 mm. Data were analyzed using the General Analysis of Variance function of the LinearModels section of Statistix V.7. Means separation was obtained by using Fisher's Protected LSD test atP= 0.05 level of significance.


CONCLUSIONS: Onions treated with SERENADE had significantly more green leaves per plant thanthe check, which is an indication of control of botrytis leaf blight and possibly other leaf diseases. Nodifferences were found between the treatments in disease severity index, or yield. No phytotoxicity wasobserved in onions sprayed with SERENADE. Disease pressure was low due to hot, dry weather.

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Table 1. Effectiveness of SERENADE for control of botrytis leaf blight on onions grown at the MuckCrops Research Station, Holland Marsh, Ontario,2007.

TreatmentRate Average # Green Average # Dead Disease Severity Yield

(Uha) IraviVplantt LeaveVplant Index (DSI)3'4 (t/ha)

SERENADE

Check

4.0 7.6 *

7. tb

2.9 ns

3.1

17.4 ns5

t8.2

76.6 ns

74.8

Average of all green leaves on 25 plants/treatment2Numbers in a column followed by a different letter are significantly different at P = 0.05, Fisher's Protected LSDtest.

I [(rating class)(no. ofplants in each rating class)]'DsI = (total no. plants per sample)(no. rating classes-l) x 100

o 75 l"u"er per replicate were graded for Vobogis leaf blightt nr= no significant differences were found between the treafinents

Funding for this project was supplied by AgraQuest and the OMAFRAAIniversity of GuelphSustainable Production Systems Program.

Muck Vegetable Cultivar Trial Research Report . 2007

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