IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Project Title: Evaluation of phytotoxicity for Sedgehammer (Halosulfuron) on Easter Lily (Lilium longiflorum ‘Nellie White’)

Protocol#:

06-010

Report date:

June 12, 2007

Authors: Heiner Lieth and Linda Dodge Department of Plant Sciences University of California Davis, CA 95616

Narrative Summary (Results/Discussion) Bulbs of Lilium longiflorum ‘Nellie White’ (size 8-9) were planted in 6-inch containers and received one application of Sedgehammer (Halosulfuron) at 1 oz/acre (1X), 2 oz/acre (2X) or 4 oz/acre (4X) rates 5 days after planting. The plants in the Control group received no Sedgehammer (Halosulfuron). The bulbs were pot-cooled for 3 weeks and then grown out in a greenhouse for 11 weeks. The trial was conducted over a total of 15 weeks from November 30, 2006 to March 14, 2007. Results The application of Sedgehammer to the top of the growing medium in pots where Easter Lily bulbs had been planted earlier, resulted in phytotoxicity index levels of zero from week 8 (at which point the plants had emerged from the substrate) to week 13 (prior to onset of flowering) (Tables 1 and 3, Figure 1). At week 15, however, substantial problems appeared in the form of serious phytotoxicity on the flowers. The effect consisted of serious distortion to the flower buds (Figures 3a, 3b and 4a). At the same time, no phytotoxicity was apparent in the control plants, indicating that the effect was due to the herbicide. All the plants which grew through the growing medium to which the herbicide had been applied had phytotoxicity levels of 5; indicating that the flowering plants were rendered unsalable. At the end of the trial, the roots of representative plants were examined by washing off the growing medium and those treated with Sedgehammer showed almost no growth of stem roots and reduced growth of basal roots compared to control plants (Figure 4b). There was also a substantial growth retardation effect due to Sedgehammer with treated plants being considerably shorter and narrower (Tables 1 and 3, Figures 2, 3a and 3b). At week 8 the plants in the 4X treatment were significantly shorter than in the Control, 1X or 2X treatments. By week 10 all plants growing in pots that had received the herbicide treatments were significantly shorter and narrower than the control. This pattern remained from then on. The ultimate canopy volume (at the time when the plants were flowering and ready for sale) was decreased to about 1/6 of the control. Discussion It should be noted that the emerging main stem had to at some point pass through the substrate at the top of the growing medium to which the herbicide had been applied. While it is curious that

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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very little damage was noted to the leaves, most of which were forming as the stem emerged, substantial damage resulted to the forming reproductive tissue. It should be noted that height reduction on Easter lily is generally a desirable thing as growers typically apply a considerable amount of growth retardant to keep the plants compact. In this study no growth retardants were applied, so that the plants which had received the herbicide treatment had more desirable plant heights than the control. However, the width was also significantly reduced and this is not desirable; growers are not interested in having the width change since a narrower plant has a poorer appearance. The premise underlying this study was that Easter lily forcers would be able to benefit from an herbicide that can be applied to pots in which the bulbs have been planted and where the pots are set in a cool location while the plants are waiting to emerge. Some growers cool their potted Easter lily plants outdoors in the late fall where weed seeds can get into the pots. These then require hand-weeding as the plants are forced in the greenhouse. Sedgehammer is not a suitable herbicide for this purpose since it does cause damage which becomes apparent just prior to shipping for Easter. Thus we conclude that Sedgehammer should not be used on Easter lilies being forced for Easter sales. Acknowledgements The research was supported through funding from the USDA IR-4 Program, Western Region based at UC Davis, Davis, CA. Personnel involved in this project included: Ron Lane (pesticide application, pest management) and Priyasheila Singh (plant culture, data collection). The materials being tested were supplied by the manufacturer/distributor. Bulbs were provided by the Easter Lily Research Foundation, Brookings OR.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Results Table Table 1. Phytotoxicity and growth changes over 15 weeks for Lilium longiflorum ‘Nellie White’ treated with 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0. Differing letters a, b, c… designate significant differences among the four means; "Yes" and "no" indicates whether there was an overall significant treatment effect at the 5% level (NA means no variation in data; "yes at 10%" means treatment effect was significant at 10% but not at the 5% level). Means ± SE (n=9) Phytotoxicity Effect of Sedgehammer on Lilium Phytotoxicity Index Increase from beginning of trial until: Treatment 8 week (NA) 10 weeks (NA) 11 weeks (NA) 0X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 1X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 2X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a 4X 0.00 ± 0.00 a 0.00 ± 0.00 a 0.00 ± 0.00 a Phytotoxicity Index increase from beginning of trial until: Treatment 13 weeks (NA) 15 weeks yes 0X 0.00 ± 0.00 a 0.00 ± 0.00 0X 1X 0.00 ± 0.00 a 5.22 ± 0.15 1X 2X 0.00 ± 0.00 a 5.33 ± 0.24 2X 4X 0.00 ± 0.00 a 5.11 ± 0.20 4X Growth Effect of Sedgehammer on Lilium Increase by week 8 of:

Treatment Height (cm) yes at

10% Average Width

(cm) no Volume Index no

0X 7.94 ± 0.41 a 8.39 ± 0.48 a 582.11 ± 83.71 a 1X 7.39 ± 0.44 a 8.33 ± 0.61 a 563.33 ± 101.22 a 2X 7.28 ± 0.40 a 7.69 ± 0.25 ab 439.31 ± 45.06 ab 4X 6.06 ± 0.41 b 6.50 ± 0.66 b 301.50 ± 68.56 b Increase by week 10 of:

Treatment Height (cm) yes Average Width

(cm) yes Volume Index yes

0X 23.61 ± 1.25 a 20.89 ± 0.77 a 10649.3 ±1310.14 a 1X 19.11 ± 1.20 bc 15.33 ± 1.06 b 4934.89 ± 894.51 b 2X 19.83 ± 0.66 b 15.50 ± 0.94 b 4983.22 ± 734.96 b 4X 16.33 ± 1.19 c 14.17 ± 1.03 b 3617.89 ± 771.12 b Increase by week 11 of:

Treatment Height (cm) yes Average Width

(cm) yes Volume Index yes

0X 32.56 ± 1.56 a 22.64 ± 0.58 a 16956.1 ±1530.56 a 1X 23.50 ± 0.82 bc 14.44 ± 0.83 b 5109.56 ± 750.70 b 2X 25.89 ± 1.11 b 16.03 ± 1.00 b 7025.67 ±1146.21 b 4X 21.56 ± 1.43 c 13.94 ± 1.12 b 4664.44 ±1033.15 b Increase by week 13 of:

Treatment Height (cm) yes Average Width

(cm) yes Volume Index yes

0X 56.72 ± 2.20 a 30.28 ± 0.68 a 52469.3 ±3823.33 a 1X 33.67 ± 1.46 b 18.11 ± 1.28 b 11760.8 ±1944.63 b 2X 34.89 ± 2.73 b 19.50 ± 1.27 b 13848.6 ±2292.87 b 4X 33.33 ± 2.73 b 16.83 ± 1.63 b 10898.2 ±2930.23 b Increase by week 15 of:

Treatment Height (cm) yes Average Width

(cm) yes Volume Index yes

0X 69.93 ± 1.63 0X 32.96 ± 0.58 0X 75910.8 ±2431.86 0X 1X 41.33 ± 1.08 1X 16.83 ± 1.36 1X 12327.8 ±1932.05 1X 2X 44.00 ± 2.84 2X 18.89 ± 1.52 2X 16769.1 ±3070.89 2X 4X 43.33 ± 2.62 4X 17.00 ± 1.22 4X 13316.7 ±2430.07 4X

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Figure 1. Phytotoxicity index ratings over 15 weeks for Lilium longiflorum ‘Nellie White’ treated with 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0. SE bars shown. (n = 9)

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Pot-Cooling

Movedpots intogreenhouse

Treat-ment

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Figure 2. Plant height, width and volume over 15 weeks for Lilium longiflorum ‘Nellie White’ treated with 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0. SE bars shown. (n = 9) (See Figure 1 for treatement legend.)

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IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Block A

Block B

Block C CONTROL 1X 2X 4X Figure 3a. Representative plants of Lilium longiflorum ‘Nellie White’ 15 weeks after 1 application of 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Block A

Block B

Block C CONTROL 1X 2X 4X Figure 3b. Representative plants of Lilium longiflorum ‘Nellie White’ 16 weeks after 1 application of 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Figure 4a. Phytotoxicity symptoms seen on Lilium longiflorum ‘Nellie White’ 15 weeks after one application of 1 oz/acre (1X) (left) and 2 oz/acre (2X) (right) Sedgehammer (Halosulfuron) at week 0. The flower buds are severely distorted and reduced in size.

CONTROL 1X 2X 4X Figure 4b. Representative plants of Lilium longiflorum ‘Nellie White’ 15 weeks after one application of 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0. The container medium has been washed from the roots. Plants treated with Sedgehammer show almost complete inhibition of stem root growth and reduced growth of basal roots compared to the control plant at left.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Materials & Methods/Recordkeeping Crop History

Crop Cultivar/Variety: Easter Lily (Lilium longiflorum ‘Nellie White’) Date of Seeding: Date of Emergence: Date of Transplanting: Bulbs received from ELRF 10/17/06, planted 11/30/06 Potting Mix: UC Mix: 1/3 sand, 1/3 peat, 1/3 bark (by volume) Pot size & spacing: 6-inch pots spaced on 12-inch centers Row spacing:

Product(s) applied prior to start of experiment:

Product Rate Application Type

Date of Application

Crop Growth Stage

Application Volume

Osmocote 15-9-12

1 tsp./pot Topdress 12/4/06 4 days after planting bulbs

NA

Experiment Information

Experimental Design: Randomized complete block Number of Reps: 9 (3 blocks x 3 reps per block)

Application Equipment: Manual spray bottles for Sedgehammer (Halosulfuron) Product(s) applied during experiment (including treatments, fertilizers, etc):

Product Rate(s) Application Type

Date of Application

Crop Growth Stage

Application Volume

Sedgehammer (Halosulfuron)

1, 2, 4 oz/acre Foliar spray OTT

12/5/06 5 days after planting bulbs

Materials & Methods: Plant Material and Culture. Bulbs of Lilium longiflorum ‘Nellie White’ (size 8-9) were received from the Easter Lily Research Foundation (ELRF), Brookings OR, on October 17, 2006. The bulbs were case-cooled at 45-50° F for 7 weeks. The bulbs were planted in 6-inch pots containing UC Mix on November 30, 2006. The potted bulbs were treated with Sedgehammer on December 5, 2006 and then cooled at 45-50° F for 3 more weeks. The potted bulbs were transferred to a greenhouse at 75°/65° F on December 28, 2006 and grown on for 11 weeks until March 14, 2007 (Figure 5). The plants were irrigated as needed during the 15-week experiment by hand with tap water for the first 4 weeks and then daily using an automatic drip system that delivered a half-strength Hoagland’s solution at 1 gallon per hour. Applications of pesticides as part of a normal pest management program were made as needed (see above). Experimental Procedure. Thirty-six plants were randomly chosen and individually tagged for treatment with 0 (Control), 1 oz/acre (1X), 2 oz/acre (2X) or 4 oz/acre (4X) Sedgehammer (Halosulfuron) with 9 replicates per treatment. These dosages were prescribed in IR4

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Ornamental Protocol 06-010 (Appendix A). The plants received the foliar spray application on December 5, 2006. Data Collection. Phytotoxicity ratings were taken at week 8, 10, 11, 13 and 15 (January 22, 2007, February 5, 12 and 26, 2007 and March 14, 2007). Visual phytotoxicity evaluations were based on a numerical rating scale ranging from 0 (no injury) to 10 (complete kill) (Table 2). Table 2. Numerical plant damage rating scale used for phytotoxicity determinations.

Rating Description of plant damage 0 No damage 1 No visible damage but unintended (non-permanent) impact 2 Slight leaf/tissue damage (curling leaves, necrosis, etc.) 3 Marginal chlorosis on some leaves (damage on up to 10% of plant) 4 10% – 20% of plant damaged 5 Significant damage to much of plant (30% - 40%) 6 40% – 60% of plant damaged 7 Chlorosis or necrosis on most of plant (60% - 70%) 8 Abscised leaves, branch dieback 9 Tissue severely damaged (80% - 100% of plant) 10 Complete kill

Plant height and width were measured at week 8, 10, 11, 13 and 15 (January 22, 2007, February 5, 12 and 26, 2007 and March 14, 2007). Plant height (cm) was measured from the container soil surface to the top of the canopy. Plant width (cm) was measured twice along perpendicular lines at the widest part of the plant, resulting in W1 and W2. For each observation a canopy volume index was calculated so as to be able to determine if canopy volume was affected by the application of herbicide. The calculation was made as H*W1*W2, where H is the height and W1 and W2 are two width measurements. The usefulness of this index is based on the fact that many of the models for such a volume calculation are of the form a*H*W1*W2. The constant “a” depends on the assumption of the shape of the canopy. Since analyses of variance are scale-independent, the conclusion will thus be for the volume of the plant canopy. Statistical Analysis. The data were analyzed using Proc GLM of the Statistical Analysis System (SAS). The phytotoxicity and change in mean value from the starting plant height, width and volume index were analyzed for significant differences using t-tests.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Greenhouse 180

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Figure 5. Greenhouse temperatures during the experiment to determine phytotoxicity of Sedgehammer (Halosulfuron) on Lilium longiflorum ‘Nellie White’.

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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Raw Data Table 3. Phytotoxicity and plant growth data collected for plants of Lilium longiflorum ‘Nellie White’ treated with one application of 0 (Control), 1 (1X), 2 (2X) or 4 (4X) oz/acre Sedgehammer (Halosulfuron) at week 0 of a 15-week experiment. (Missing data for week 15 is due to theft of plants.) Phytotoxicity Report Form Lilium Sedgehammer IR4 Trial Phytotoxicity at week Plant Size at week 8 Plant Size at week 15 Height Width1 Width 2 Height Width1 Width 2

Treatment Block Rep 8 10 11 13 15 (cm) (cm) (cm) (cm) (cm) (cm) Control A 1 0 0 0 0 0 10 7.5 7 Control A 2 0 0 0 0 0 8 8 7.5 72.5 31.5 33 Control A 3 0 0 0 0 0 6 7 6 Control B 1 0 0 0 0 0 7 7 7 74 31 30 Control B 2 0 0 0 0 0 7 9.5 9 68 32 32 Control B 3 0 0 0 0 0 9 11.5 11 74 34 35 Control C 1 0 0 0 0 0 8 9 9 72 32 34 Control C 2 0 0 0 0 0 7.5 9.5 8 66 33 34 Control C 3 0 0 0 0 0 9 9.5 8 63 36 34

Mean 0.0 0.0 0.0 0.0 0.0 7.9 8.7 8.1 69.9 32.8 33.1 1X A 1 0 0 0 0 5 6 7 6 42 12 14 1X A 2 0 0 0 0 5 8 11 8.5 40 17 19 1X A 3 0 0 0 0 6 9 10 9 43 19 18 1X B 1 0 0 0 0 5 6 6 6.5 48 14 15 1X B 2 0 0 0 0 5 5.5 6.5 6 37 11 12 1X B 3 0 0 0 0 5 8 8 9 38 21 20 1X C 1 0 0 0 0 6 8 11 11 43 22 24 1X C 2 0 0 0 0 5 7 7.5 7 40 12 13 1X C 3 0 0 0 0 5 9 10 10 41 20 20 Mean 0.0 0.0 0.0 0.0 5.2 7.4 8.6 8.1 41.3 16.4 17.2

2X A 1 0 0 0 0 6 9 8 9 50 14 13 2X A 2 0 0 0 0 4 7 7.5 6 51 14 15 2X A 3 0 0 0 0 6 8 8.5 8 30 15 15 2X B 1 0 0 0 0 5 9 8 8 54 24 24 2X B 2 0 0 0 0 5 6 7 7.5 48 21 20 2X B 3 0 0 0 0 5 7 6.5 6.5 41 15 14 2X C 1 0 0 0 0 6 7 8 8 46 23 21 2X C 2 0 0 0 0 6 5.5 7 8 31 21 20 2X C 3 0 0 0 0 5 7 9 8 45 25 26 Mean 0.0 0.0 0.0 0.0 5.3 7.3 7.7 7.7 44.0 19.1 18.7

4X A 1 0 0 0 0 6 6.5 8 7 44 14 14 4X A 2 0 0 0 0 5 5 4 3.5 42 16 15 4X A 3 0 0 0 0 6 7 8 8 32 19 17 4X B 1 0 0 0 0 4 5 4 4.5 42 12 12 4X B 2 0 0 0 0 5 6 8 8 50 21 24 4X B 3 0 0 0 0 5 7 7 7.5 56 16 18 4X C 1 0 0 0 0 5 4 4.5 4 33 17 18 4X C 2 0 0 0 0 5 8 9.5 9 50 23 22 4X C 3 0 0 0 0 5 6 6.5 6 41 14 14 Mean 0.0 0.0 0.0 0.0 5.1 6.1 6.6 6.4 43.3 16.9 17.1

IR-4 Ornamental Horticulture Program Research Report Form

Researcher(s): Heiner Lieth, UC Davis PRNumber(s): 25343

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APPENDIX A Phytotoxicity to ornamental horticulture plants from tools to manage broadleaf weeds and sedges. Ornamental Protocol Number: 06-010 Objective: Determine phytotoxicity of Manage (halosulfuron), Sulfentrazone 0.2G, and V-10142 to unlabelled

perennial plants commonly grown in nurseries.

Experimental Design: Plot Size: Must be adequate to reflect actual use conditions.

Replicates: Minimum of 3 replications (preferably 4) with 3 plants per replicate

Application Instructions: Apply first application over the top of plants just breaking dormancy or, under climates where plants do not go totally dormant, apply prior to active growth in the spring. See table for product specific information.

Plant Materials: See attached list of plant materials. Plants grown in field containers are preferred to in-ground.

Evaluations: Record plant height & width at initial and final evaluations. At 1, 2, and 4 weeks after each application, record phytotoxicity on a scale of 0 to 10 (0 = No phytotoxicity; 10 = Complete kill). If appropriate, also include ratings for chlorosis, defoliation, stunting or other growth effects on a scale of 0 to 10 (0 = No effect; 10 = Complete plant affected). If any phytotoxicity is observed in treated plants, take pictures comparing treated and untreated plant material.

If different application methods or evaluations are made, please clearly specify differences in final report and explain how they enhanced results.

Recordkeeping: Keep detailed records of weather conditions including temperature and precipitation, soil-type or soil-less media, application equipment, irrigation, liner size, plant height & width, and plant growth stage at application and data collection dates.

Treatments: Product Rates Special Instructions Contact Information

to obtain materials and any needed adjuvants

Sedgehammer 75WG (halosulfuron)

1 oz per acre (0.047 lb ai) 2 oz per acre (0.094 lb ai) 4 oz per acre (0.188 lb ai)

Always use 0.25% v/v of a non ionic surfactant. If severe phyto symptoms do not occur and where feasible apply a second application 4-6 weeks later at identical rates.

Kory Wheeler 928-819-1592 Kwheeler@gowanco.com

Sulfentrazone 0.2G (sulfentrazone – 0.2% active)

0.125 lb ai/acre 0.25 lb ai/acre 0.5 lb ai/acre

2 applications on a 4 week interval

FMC, Bobby Walls, 919-735-3862, bobby_walls@fmc.com

V-10142 75WG 0.5 lb ai/acre 1.0 lb ai/acre 2.0 lb ai/acre

2 applications on a 4 week interval

Valent, Joe Chamberlin, 770-985-0303, jcham@valent.com

Untreated ------ ------ Reports:

Reports must include: Results summary (no more than one page) Summary table with appropriate statistical analyses Experimental design and materials and methods Appendices: raw data and recordkeeping information as listed above If pictures were taken, please include them. A report submitted electronically is preferred but not required. If the report is provided electronically, the basic report can be

sent in MS Word or WordPerfect, the recordkeeping information as pdf or other electronic documents, and the raw data in MS Excel or other suitable program such as ARM.

Please direct questions to: Cristi Palmer, IR-4 HQ, Rutgers University, 681 US Hwy 1 S, North Brunswick, NJ 08902-3390, Phone 732-932-9575 x629, palmer@aesop.rutgers.edu OR Ely Vea, 308 Aston Forest Lane, Crownsville, MD 21032, Phone & FAX#: 410-923-4880, E-mail: evvea@comcast.net.