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Rice Experiment Station - CRRF Breeding Program Virgilio C. Andaya, Ph.D., Director of Plant...
Transcript of Rice Experiment Station - CRRF Breeding Program Virgilio C. Andaya, Ph.D., Director of Plant...
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Wednesday, August 27, 2014
New Research Building
California Cooperative Rice Research Foundation, Inc.
University of California
United States Department of Agriculture Cooperating
Rice Experiment Station P.O. Box 306, Biggs, CA 95917-0306
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About the Cover
A new research building funded by the California Cooperative Rice
Research Foundation was completed and dedicated in December
2013. The metal building includes a storage area for the research
combines and planters, a milling lab, seed processing area, a sample
cleaning and drying room, research assistant offices, mezzanine
storage, men’s and women’s bathrooms with showers and a staff
meeting/break room. The project included instillation of a septic
system to serve the entire Rice Experiment Station and an expanded
concrete service area. Field day lunch will be served from the new
facility.
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California Cooperative Rice Research Foundation, Inc.
Board of Directors
Sean Doherty, Dunnigan (Chairman)
Bert Manuel, Yuba City (Vice-Chairman)
Gary Enos, Glenn (Treasurer)
Steve Willey, Nicolaus
Carl Funke, Willows
Aaron Scheidel, Pleasant Grove
Charlie Mathews, Jr., Marysville
Peter Panton, Pleasant Grove
Dennis Spooner, Willows
Gary Stone, Richvale
Lance Benson, Durham
Rice Experiment Station Staff
Administrative
Kent S. McKenzie, Ph.D., Director
Lacey R. Stogsdill, Administrative Assistant
Pamela L. Starkey, Administrative Assistant
Rice Breeding Program
Virgilio C. Andaya, Ph.D., Director of Plant Breeding
Farman Jodari, Ph.D., Plant Breeder, Long Grains
Stanley O. P.B. Samonte, Short & Premium Medium Grains
Jeffrey J. Oster, M.S., Plant Pathologist, Disease Resistance
Cynthia Andaya, Ph.D., Research Scientist
Matthew Calloway, Breeding Nursery Manager
Baldish K. Deol, Plant Breeding Assistant
Ravinder Singh Gakhal, Plant Breeding Assistant
Christopher Putz, Plant Breeding Assistant
Davinder Singh, Plant Breeding Assistant
George Yeltatzie, DNA Lab Technician
Field Operations and Maintenance
Burtis Jansen, Field Supervisor
Joe Valencia, Mechanic and Operator
Randy Jones, Maintenance and Operator
Shane Odekirk, Maintenance and Operator
UC Rice Research
J. Ray Stogsdill, Staff Research Associate II
Kevin Goding, Staff Research Associate II
Steve Johnson, Staff Research Associate I
Whitney Brim-DeForest, Ph.D. Candidate
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2014 Rice Field Day Program
7:30—8:30 Registration and Poster Viewing
Posters and Demonstrations
1. Rice Waste Discharge Requirement: Pesticide Monitoring
Requirements Under the Order (California Rice Commission)
2. Rice Pesticide Program- Thiobencarb Monitoring Results and
Outcomes (California Rice Commission)
3. Thiobencarb Management Practices & Permit Conditions per
DPR Enforcement Compendium (California Rice Commission)
4. Rice Pesticide Use Matrix (California Rice Commission)
5. Herbicide Resistance Stewardship Chart and Handout
(California Rice Commission)
6. Can The Red Shouldered Stink Bug Cause Pecky Rice? (L. Espino
and L. Godfrey, UCCE)
7. The Effect of Silicon Fertilization on Performance of Rice Against
Rice Water Weevil (Lissorhoptrus oryzophilus Kuschel) M.A.
Aghaee and L.D. Godfrey, UCD &UCCE)
8. Target-Site Resistance To Propanil In Cyperus Difformis L.
(Smallflower Umbrella Sedge): Implications For Management In
Rice Fields Of California (R.M. Pedroso, R. Alarcon-Reverte, A.J.
Fischer, UCD)
9. Weed Population Dynamics In Alternative Irrigation Systems (W.
Brim-DeForest, B.A. Linquist, A.J. Fischer, UCD)
10. Differentiation Of Leptochloa Fusca Spp. Fasicularis And
Uninervia (Sprangletop) (F.L. Borghesi, W. Brim-DeForest, A.J.
Fischer, UCD)
11. Resistance Of Leptochloa Fusca Spp. Fasicularis (Sprangletop) To
Clomazone And Accase Inhibitors(W. Brim-DeForest, A.J.
Fischer, UCD
12. Dynamics of Weed Emergence In California Rice Systems (W.
Brim-DeForest, R. Pedroso, UC Davis; L. Boddy, Marrone Bio
Innovations; B.A. Linquist, A.J. Fischer, UCD)
13. Combining Genetic Resistance to Blast, Stem Rot and Sheath
Spot (J. Oster, V. Andaya, C. Andaya, K.S. McKenzie, F. Jodari,
S.O.P.B. Samonte, RES)
14. Disease Symptom Posters (J.J. Oster, RES)
15. Development And Performance Of Blast Resistant Near-Isogenic
Lines Of Rice In M-206 Genetic Background (V.C. Andaya, J.J.
Oster, C.B. Andaya, F. Jodari, S.O.P.B. Samonte, and K.S.
McKenzie)
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16. Combining Genetic Resistance to Blast Stem Rot and Sheath
Spot. (J. Oster, V. Andaya, C. Andaya, K.S. McKenzie, F. Jodari,
and S. O.S.P.B Samonte, RES)
17. California Rice Breeding: Yield Increase Rate Due To Semi-Dwarf
Varietal Releases By The Rice Experiment Station (S.O.P.B.
Samonte, V.C. Andaya, F. Jodari, J.J. Oster, C.B. Andaya, and
K.S. McKenzie)
18. Using Alternative Water Management to Reduce Greenhouse Gas
Emissions and Maintain Yields in California Rice Systems. (G.
LaHue, M.A.A. Adviento-Borbe, C. van Kessel, J.R. Stogsdill, and
B.A. Linquist, UCD & UCCE)
19. Do Nutrient Management Practices That Improve N Use
Efficiency Reduce Greenhouse Gas Emissions In Flooded Rice
Fields? (A. Adviento-Borbe, M. Anders, C. Pittelkow, B. Linquist,
and C. van Kessel, UCD &UCCE)
20. Modeling of Rice Response to Temperature and Photoperiod for
CA Major Rice Varieties (H. Sharifi, R. Mutters, C. Greer, L,
Espino, R.J. Stogsdill, R. Wennig, R. Hijmans, C.V. Kessel, J.
Hill, B. Linquist UCD &UCCE)
21. The Effect of Biochar on Rice Seed Germination, Early Seedling
Vigor, and Post Flood Plant Development (R. Green, Benchmark
Development and S. Hughes, Charganics)
22. Identification Of Novel Low Phytic Acid Mutants In Rice Using
Reverse Genetics (S.I. Kim and T. H. Tai)
23. Identification Of Mutations In Genes Encoding Two Major Rice
Allergens Using TILLING By Sequencing (A. Chun, D. Burkart-
Waco, and T. H. Tai, USDA-ARS & UCD)
24. Development Of Molecular Markers For Evaluation Of Low
Temperature Germ Inability And Seedling Cold Tolerance In Rice
Germplasm (D.Y. Hyun, G.A. Lee, M. J. Kang, M. C. Lee, J. G.
Gwag, Y.G. Kim, D. Burkart-Waco, S.I. Kim, and T. H. Tai,
USDA-ARS & UCD)
25. Extending Shelf Lives Of Rough And Brown Rice Using Infrared
Radiation Heating (C. Ding, R. Khir, Z. Pan, and K. Tu USDA-
ARS & UCD)
26. Impact Of Infrared Heating On Physicochemical Properties Of
Rice Under Accelerated Storage Conditions (C. Ding, R. Khir, Z.
Pan, K. Tu, USDA-ARS & UCD)
27. Effective Disinfection Of Rough Rice Using Combined Pulsed
Ultraviolet Light And Holding Treatment (B. Wang, R. Khir, Z.
Pan, N. Mahoney, USDA-ARS & UCD)
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28. The Contribution of Sacramento Valley Rice Systems to
Methylmercury in the Sacramento River (C. Tanner, L.
Windham-Myers, J. Fleck, K. Tate, S. McCord, and B. Linquist,
UCD,USGS & UCCE)
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8:30 - 9:15 a.m. GENERAL SESSION
Welcome by Sean Doherty, Chairman, CCRRF
CCRRF Business Meeting
Financial Report, Gary Enos, Treasurer, CCRRF
Directors Nomination Committee Report,
Kent McKenzie, RES
Rice Research Trust Report, Steve Willey, Chairman, RRT
California Rice Research Board Report,
Seth Fiack, Chairman, CRRB
California Rice Industry Award Presentation, Bert Manuel
Vice Chairman, CCRRF
9:20 - 10:45 a.m. MAIN STATION TOUR
Two tours occur simultaneously and repeat.
Blue & Green Groups to Trucks
Rice Variety Development
(V.C. Andaya, F. Jodari, S.O. Samonte, and J.J. Oster, RES)
Fifteen Years of Pyrethroid Insecticide Use in Rice – Are These
Products Still Effective? Are There Viable Options Nearing
Registration? What Is the Future of IPM of Rice Invertebrate Pests? (L. Espino, L.D. Godfrey K. Gooding, M. Aghaee, UCCE & UCD)
10:30 - 10:45 a.m. Refreshments - New Warehouse
10:45 - Noon Repeat Station Tour with
Red & White Groups
9:20 - 10:45 a.m. HAMILTON ROAD TOUR
Two tours occur simultaneously and repeat.
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Red & White Groups to Buses
Rice Weed Control: Herbicide Programs, New Chemicals, and Weed
Management
(A.J. Fischer, W. Brim-DeForest, R. Alarcon-Reverte, R. Pedroso, B.A.
Linquist, C. Greer, L. Espino, R.G .Mutters, J.E. Hill, S. Johnson, and
J.R. Stogsdill, UCD & UCCE)
10:30 - 10:45 a.m. Refreshments – Research Building Canopy
10:45 - Noon Repeat Hamilton Road Tour with
Blue & Green Groups
Noon Luncheon Concludes Program
Lunch will be served in the New Research Building and with seating
at the tables on the lawns under the canopies
2.0 hours of Continuing Education credit for this 2014 Rice Field Day
has been granted from Cal/EPA Department of Pesticide Regulation
Disclaimer
Trade names of some products have been used to
simplify information. No endorsement of named
products is intended nor is criticism implied of similar
products not mentioned.
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Introduction By Sean Doherty
On behalf of the Board of Directors, staff and UC cooperators,
welcome to Rice Field Day 2014. Field Day is our annual opportunity
to highlight the research that is at underway the Rice Experiment
Station for the California Rice Industry. It is also the annual business
meeting for the grower/owners of the California Cooperative Rice
Research Foundation.
2014 has certainly proved to be a year of “uncertainty” for the
California rice industry as I am sure all of you have experienced. I am
pleased to report that we have been able to continue our breeding and
research activities without any reduction. This has been possible
with the continued financial support from the California Rice
Research Board as well as the Foundation and the Rice Research
Trust. RES does have a productive well drilled in 1978, that has been
tested and available if needed. I would like to acknowledge the
support we have received from the Richvale Irrigation District and
other waters districts in recognizing our critical role in California
rice.
The highlight of the day is the field tours where you are able to hear
from the researchers and see the nurseries on the main station as
well as weed control research at the Hamilton Road site. Dr. Virgilio
“Butz” Andaya, Director of Plant Breeding, is overseeing the medium
grain program and will be reporting on that project. Dr. Farman
Jodari will update you on his long grain program and varieties. Dr.
Stanley Samonte will present his work on premium quality and short
grain varieties. Rice Experiment Station Pathologist Jeff Oster
continues his work on rice diseases and will be speaking to you at his
rice disease nursery. Dr. Luis Espino, UC Cooperative Extension
Farm Advisor will also present the ongoing work on rice insect pests
on the main station tour.
Dr. Albert Fischer, UC Davis Professor, will be leading you on a
walking tour of the weed research nursery at the Hamilton Road site.
Dr. Cynthia Andaya and Mr. George Yeltatzie have our DNA marker
lab in full operation to support the RES Breeding Program.
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The Rice Experiment Station remains committed to the production of
clean, weed and disease free foundation seed for the California rice
growers. We continue work in cooperation with the Foundation Seed
and Certification Services and the California Crop Improvement
Association. The certified seed program is an essential part of
maintaining genetic purity in our varieties and insuring the highest
quality seed is available to the industry. The seed program is self
supporting and is not funded by the Rice Research Board. Total
acreage in seed production was reduced about 20% this year, by
rotation into available smaller fields, but no varieties were dropped
and two experimentals lines are under increase.
I would like to acknowledge the many businesses and growers who
support Rice Field Day through financial donations, agro chemicals
and use of trucks for our tours. This year we have also included
equipment displays from several sponsors. This industry support is
very important to the success of the Field Day. The supporters are
listed in your program and we thank them again for their assistance.
Thank you for attending Rice Field Day and supporting our research
programs. If you have any questions about Field Day or the Rice
Experiment Station, please take the opportunity to talk with the
Directors and staff. There is a great deal of useful information on
display today and I invite you to visit the displays and posters as well
as the field tours.
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D. Marlin Brandon Rice Research Fellowship In 2000, a memorial fellowship was established to provide financial
assistance to students pursuing careers in rice production science and
technology as a tribute to Dr. D. Marlin Brandon, past Director and
Agronomist at the Rice Experiment Station. The California Rice
Research Board made a one-time donation to the Rice Research Trust
of $52,500 with $2,500 used for the 2000 fellowship. The Rice
Research Trust contributed an additional $50,000 and established a
fellowship account. Interest from investments on the $100,000
principal is used to provide grants to the D. Marlin Brandon Rice
Scholars. Twenty-two fellowships have been issued from 2000 to
2011.
Beginning in 2012 some changes were made to offer more financial
support with two-year fellowship in the amount of $10,000 to
encourage an undergraduate to pursue graduate study in rice
research. This effort not been successful and the Board has decided to
return to offering the previous annual fellowships. Application
materials are available by contacting the Rice Experiment Station.
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SUBMITTED POSTER ABSTRACTS
CALIFORNIA RICE BREEDING: YIELD INCREASE RATE
DUE TO SEMI-DWARF VARIETAL RELEASES BY THE RICE
EXPERIMENT STATION
S.O.P.B. Samonte, V.C. Andaya, F. Jodari, J.J. Oster, C.B. Andaya,
and K.S. McKenzie, RES
Rice productivity per unit area has been increasing over the years.
This has been attributed to better management practices, such as for
soil fertility, water, insect pests, diseases, and weeds, and also to
improved rice varieties. Rice grain yields in California are the highest
in the United States and these have increased from 4775 lb/acre in
1960 to 8350 lb/acre in 2011 based on USDA-ERS data published in
2012.
The primary mission of the California Cooperative Rice Research
Foundation, Inc., (CCRRF) Rice Experiment Station (RES) in Biggs,
CA, is to develop improved rice varieties for all grain and market
types and to sustain high and stable grain yield and quality with
minimum environmental impact for the benefit of California rice
growers. The objective of this study was to determine the grain yield
increase rate due to semi-dwarf varieties released by the Rice
Experiment Station from the 1970s to the 2000s.
In 2012, 25 semi-dwarf varieties (conventional long, medium, and
short grain types) released by RES were planted at two sites within
the station. These included L-206, M-205, M-206, and S-102, which
produced mean grain yields of 10,570, 10,650, 10200, and 9440
lb/acre, respectively, in Statewide Yield Trials at RES in 2012.
Planting was done by wet-seeding in site 1 and drill-seeding in site 2.
Data on grain yield and yield-related traits were measured. The RES
Field Day poster, however, focuses on the grain yield trends. The
second year of this study is being conducted in 2014, and the
combined 2012 and 2014 data will be analyzed.
Grain yields differed significantly among varieties, ranging from 8091
lb/acre for Calrose-76 to 10,740 lb/acre for M-206. Varietal releases
have increased grain yields significantly. Grain yield increase rate
due to varietal releases was estimated at 54 lb/acre/year. This rate,
however, is a preliminary estimate based on one year’s data. To
account for common genotype x environment interactions that occur
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in yield trials, a second year of experiments is being conducted in
2014. Results from this study will not only be useful in analyzing past
varieties, but will also be useful in planning and breeding rice for the
future.
DEVELOPMENT AND PERFORMANCE OF BLAST
RESISTANT NEAR-ISOGENIC LINES OF RICE IN M-206
GENETIC BACKGROUND
V.C. Andaya, J.J. Oster, C.B. Andaya, F. Jodari, S.O.P.B. Samonte,
and K.S. McKenzie, RES
The Rice Experiment Station (RES) located in Biggs, California,
initiated a project to develop near-isogenic rice lines (NILs)
containing different resistance genes to rice blast (Magnaporthe
grisea) in the genetic background of M-206, a temperate Japonica
medium grain variety. M-206, a commercial rice variety, is a popular
and widely grown variety in the Sacramento Valley and is susceptible
to rice blast. Ten blast resistance genes (Pi genes) were used in the
gene introgression, namely, Pi1, Pi2, Pi9, Pi33, Pi40, Pib, Pikh, Pikm,
Pita2, and Piz5.
Gene introgression was performed using at least seven backcrosses to
M-206 using biological screening initially, followed by marker-
assisted backcrossing using PCR-based DNA markers. Supplemental
blast screening was performed to verify presence of resistance genes
in plants used for crossing. The NILs were advanced to homozygosity
and given individual designation that specifies the cultivar used and
the resistance gene introgressed (e.g. M-206+Pi33). The agronomic
and yield performance of the NILs, M-206, and check varieties were
evaluated in replicated field experiments at RES in 2013. Seven of
the NILs were also included in select locations of the Statewide Yield
Test in 2012 and 2013.
This poster describes the development of the NILs and their
performance in comparison to M-206 in terms of a number of
agronomic and grain traits. It will also report if there are negative or
positive effects of individual blast resistance genes to these measured
traits.
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DO NUTRIENT MANAGEMENT PRACTICES THAT IMPROVE
N USE EFFICIENCY REDUCE GREENHOUSE GAS
EMISSIONS IN FLOODED RICE FIELDS?
M.A.A. Adviento-Borbe, M. Anders, C. Pittelkow, B. Linquist and
C. van Kessel, Dept. of Plant Sciences, UCD
Irrigated rice fields release to the atmosphere significant amounts of
CH4 and N2O and fluxes of these greenhouse gases (GHG) can be
reduced by managing efficiently the N fertilizer inputs during the
growing season. Field studies were conducted to evaluate the effects
on CH4 and N2O emissions of the different N fertilizer management
practices that aimed to increase N use efficiency and reduce GHG
emissions in irrigated lowland rice systems in California and
Arkansas. Rice yield and GHG emissions were determined from drill
seeded (AR, CA1, CA2; 84-70 kg seed ha-1) and wet seeded (CA3, CA4;
224 kg seed ha-1) farmer’s and experimental fields fertilized with
various N fertilizer sources such as aqua ammonia, urea, polymer
coated urea (Agrotain™), and ammonium sulfate at recommended N
rates ranging from 100-168 kg N ha-1. These N fertilizers were
applied either broadcast or subsurface once or twice during the rice
growing period. Emissions of CH4 and N2O were measured
throughout the rice crop cycle using flux chamber and gas
chromatography method. At all sites, grain yields were 3.5 to 6.2 Mg
ha-1 without N fertilizer application. The addition of N fertilizer
increased yield by approximately 113% with no consistent trends
among N sources, number and depth of N fertilizer applications.
Fertilizer use efficiency ranged from 17 to 64% with the highest in
wet seeded fields. In all locations, different types of N fertilizer had
no effect on annual CH4 and N2O emissions however, magnitudes of
CH4 and N2O emissions were 1.5 and 1.8 times higher with N
application compared with unfertilized treatments (81 kg CH4-C and
0.56 kg N2O-N ha-1 yr-1) , respectively. There were no clear patterns
whether application of different N fertilizer sources (urea, polymer
coated urea, ammonium sulfate, aqua N) effectively decreased global
warming potentials (GWP) because annual GWP were variable in all
sites. Yield-scaled annual GWP tended to decrease in split N fertilizer
treatments but this was not consistent across sites. Our results show
that N management practices that improve fertilizer use efficiency
such as crop-specific urea fertilization, using slow-release fertilizer,
inhibitors, or injected aqua N may have potential to reduce GHG
emissions but require further assessment.
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MODELING OF RICE RESPONSE TO TEMPERATURE AND
PHOTOPERIOD FOR CA MAJOR RICE VARIETIES.
H. Sharifi, R. Mutters, C. Greer, L, Espino, J.R. Stogsdill, R.
Wennig, R. Hijmans, C. van Kessel, J. Hill, B. Linquist UCD & UCCE
The development of rice is affected by temperature and photoperiod
sensitivity. The ability to predict developmental stages is essential for
efficient rice crop management. Management decisions--which are
often based on crop development--can significantly affect yield and
profitability. This research aims to develop a model that accurately
predicts important growth stages for rice to enable farmers to
improve management decisions.
To achieve this objective we use historical data from region-wide
variety trials and additional data from field and greenhouse trials to
(i) quantify the effect of air temperature and photoperiod sensitivity
on rice development and (ii) develop a predictive model of the
principal growth stages of rice, including panicle initiation (PI),
heading (H), and physiological maturity (PM).
Nine major CA rice varieties were selected for this study: M-104, M-
105, M-202, M-205, M-206, M-401, CM101, S-102, and L-206. These
varieties were chosen to represent a range of photoperiod, crop
duration, and grain size. Historical data was obtained from
University of California Cooperative Extension (UCCE) Rice Variety
Evaluation tests (RVE) 2000-2013 for all varieties. Field trials (2011-
current) supplement the RVE data. A greenhouse study at University
of California Davis Vegetable Crops facility complements field data
by permitting more precise observation of photoperiod sensitivity
effect by way of staggered planting dates and a controlled
temperature environment.
The preliminary results of the greenhouse study indicate two groups
of varieties based on their response to photoperiod: photoperiod
sensitive (M-401) and photoperiod non-sensitive (CM101, M-104, M-
105, M-202, M-205, M-206, S-102 and L-206) varieties. Thermal-time
model was developed to predict the time to PI, H, and PM stages.
Historical, field, and greenhouse data were used to calibrate and
validate the models. Except for M-401, Thermal time model
accurately predicts the time to all stages for varieties in this study.
This is further supported by preliminary results from our greenhouse
study.
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This model will be used to develop a unique predictive tool for
California (CA) rice farmers that will help them make more informed
management decisions throughout rice crop development.
USING ALTERNATIVE WATER MANAGEMENT TO REDUCE
GREENHOUSE GAS EMISSIONS AND MAINTAIN YIELDS IN
CALIFORNIA RICE SYSTEMS
G. LaHue, M.A.A. Adviento-Borbe, C. van Kessel, J.R.
Stogsdill, and B. A. Linquist Dept. of Plant Sciences, UCD & UCCE
Rice has traditionally been grown under continuously flooded
conditions in California, which has allowed growers to achieve high
grain yields, use irrigation water efficiently, and maintain high
nitrogen use efficiency (NUE). Recently however, there has been
some concern that these anaerobic growing conditions may cause
problems such as high methane (CH4) emissions, arsenic (As) uptake
by rice plants, and methyl-mercury formation. Studies in other rice-
growing regions have shown that the alternation of wet (flooded) and
dry (drained) growing conditions (referred to as AWD) has the
potential to mitigate the aforementioned problems. While it is
possible that conventional water management will continue to be the
standard practice in California, it is important to evaluate the
agronomic viability of AWD in California and prepare for scenarios
where growers might face legislative pressure to implement
alternative water management strategies.
In this study, nitrous oxide (N2O) and CH4 emissions from three
water management treatments were compared: water-seeded rice
grown with continuous flooding (WS-C); water-seeded rice grown
under flooded conditions until canopy closure and then flush-irrigated
(WS-AWD); and drill-seeded rice grown with flush-irrigation (DS-
AWD). The three treatments were also compared for rice grain yield
and N response. The WS-AWD treatment reduced CH4 emissions by
over 50% and the DS-AWD treatment cut CH4 emissions by almost
90% relative to the WS-C treatment. In contrast, N2O emissions were
the highest in the DS-AWD treatment and did not differ significantly
between the WS-AWD and the WS-C treatments, although N2O
emissions were < 1% of the total Global Warming Potential (GWP)
during the growing season. The total GWP (kg CO2 eq ha-1 season-1)
was therefore lowest in the DS-AWD treatment and highest in the
WS-C treatment. Rice grain yields and N response were not
significantly different among the three water management
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treatments. Alternative water management therefore represents a
promising alternative to allow California rice growers to maintain
rice grain yields and N-use efficiency while significantly decreasing
greenhouse gas emissions. However, more research is needed on
AWD to confirm these findings and to evaluate both its economic
viability and its potential for large-scale applications.
EXTENDING SHELF LIFE OF ROUGH AND BROWN RICE
USING INFRARED RADIATION HEATING
C.Ding1,3 R. Khir1,4 Z. Pan1,2 K. Tu3 1 Department of Biological and Agricultural Engineering, UCD 2 Healthy Processed Foods Research Unit, Western Regional Research
Center, USDA 3College of Food Science and Technology, Nanjing
Agricultural University, 4 Department of Agricultural Engineering
The objective of this study was to investigate the effect of IR heating
and tempering treatments on storage stability of rough and brown
rice. Samples of freshly harvested medium grain rice variety M-206
with initial moisture content of 25.03±0.21% (d.b.) were used. The
samples were dried using infrared (IR), hot air (HA) at 43°C and
ambient air (AA) for comparison. For IR drying, rice was heated to
temperature of 60 °C under radiation intensity of 4685 W·m-2,
followed by 4-h tempering and natural cooling. The dried samples
were divided into two portions which were respectively used as rough
and brown rice for storage at 35±1 °C with relative humidity of 65±3%
for ten months. The drying characteristics and milling quality of rice
were determined. Free fatty acid, peroxide value and iodine value
were measured to detect any notable degradation of lipids in rough
and brown rice during storage. High heating and drying rates of rice
were achieved under IR heating. It took only 58 s to heat rough rice to
temperature of 60 °C with corresponding moisture removal of 2.17
percentage points during IR heating. The total moisture removal
after natural cooling reached to 3.37 percentage points without
additional energy input. IR drying did not show any adverse effects
on milling quality of dried rice. Additionally, it resulted in an
effective inactivation of lipase and consequent improvement in the
long-term storage stability of rough and brown rice. It is concluded
that the improvement in rough and brown rice stability during
storage can be achieved through drying rough rice using IR heating to
temperature of 60°C followed by tempering for 4 h and natural
cooling. IR drying provides a potential to store brown rice instead of
rough rice with extended shelf life and reduced cost.
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IMPACT OF INFRARED HEATING ON PHYSICOCHEMICAL
PROPERTIES OF RICE UNDER ACCELERATED STORAGE
CONDITIONS
C. Ding1,4, R. Khir1,2, Z. Pan1,3, K. Tu4 1Department of Biological and Agricultural Engineering, University
UCD, 2 Department of Agricultural Engineering, Faculty of
Agriculture, Suez Canal University,3 Healthy Processed Foods
Research Unit, USDA-ARS-WRRC4 College of Food Science and
Technology, Nanjing Agricultural University
Infrared (IR) radiation heating has shown a great potential to achieve
high drying rate, good milling quality of rough rice and effective
stabilization of rice bran. However, further study on the effect of IR
on physicochemical prosperities of rice during storage is needed. The
aim of this research was to characterize the changes in pasting,
thermal and cooking properties of infrared dried rice during storage.
Freshly harvested medium grain rice (M-206) with moisture content
of 20.0 ± 0.2% (w.b.) was used for this study. The samples were
divided into three potions and dried using infrared (IR) heating, hot
air (HA) and ambient air (AA). For IR heating, the samples were
heated to temperature of 60 °C using a catalytic emitter under
radiation intensity of 5348 W/m2 followed by 4 h tempering and
natural cooling. All of the dried rice samples were stored at 35 ºC for
ten months. The pasting and thermal properties and texture, water
uptake and volume expansion ratio and solid loss during cooking
were determined over the storage time. Similar trends were observed
in pasting properties for rice dried using IR, HA and AA. The peak
viscosity and breakdown increased within the first 4 months of
storage and then decreased for dried rice. The peak viscosity of rice
dried with IR was less than those of rice dried with HA and AA.
There was no significant alteration on thermal properties among rice
samples tested. Cooking properties including, volume expansion,
water uptake, solids loss and texture changed in similar fashions for
rice dried using IR, HA and AA. We concluded that the drying using
IR heating under conditions of temperatures of 60 ºC followed by 4 h
tempering and natural cooling has no adverse effect on
physicochemical properties of rice after storage.
19
EFFECTIVE DISINFECTION OF ROUGH RICE USING
COMBINED PULSED ULTRAVIOLET LIGHT AND HOLDING
TREATMENT
B. Wang1,3, R. Khir1,4, Z. Pan1,2, T. H. McHugh2, N.Mahoney2 1Department of Biological and Agricultural Engineering, UCD. 2
Healthy Processed Foods Research Unit, USDA-ARS West Regional
Research Center, 3School of Food and Biological Engineering, Jiangsu
University, 4Department of Agricultural Engineering, Suez Canal
University
There is a great need in developing environmental friendly
technologies for disinfecting rough rice to inhibit the production of
aflatoxins. The objective of this study was to investigate the
effectiveness of disinfection of rough rice against A. flavus using
integrated pulsed ultraviolet light (PUV) and holding treatment.
Samples of freshly harvested medium grain rice (M-206 variety) with
initial moisture content of 23.1±0.1% (w.b.) were used for conducting
this study. The inoculated samples were treated using PUV under
different light intensities ranging from 0.10 to 0.40 W/cm2 and
durations ranging from 10 to 40 s. After PUV treatment, holding
treatment was conducted by keeping the treated samples in an
incubator set at 60 ºC for 2 h followed by natural cooling. The
reductions on population size of A. flavus spores, moisture removal
and milling quality of rough rice were determined. The results
revealed that the PUV treatment under light intensity of 0.12 W/cm2
for 20 s led to temperature of 60 ºC and a reduction of 0.3 log cfu/g on
population size of A. flavus spores. After holding treatment, a 5.0 log
cfu/g reduction was achieved. The corresponding total moisture
removal reached to 4.1% point. There was no adverse effect of
integrated PUV and holding treatment on the milling quality of rough
rice. It has been concluded that simultaneous drying and effective
disinfection of rough rice can be achieved using combined PUV and
holding treatment.
20
THE CONTRIBUTION OF SACRAMENTO VALLEY RICE
SYSTEMS TO METHYLMERCURY IN THE SACRAMENTO
RIVER
C. Tanner, L. Windham-Myers, J. Fleck, K. Tate, S. McCord and B.
Linquist. UCD, United States Geological Survey, and UC Cooperative
Extension.
In anoxic, mercury-contaminated sediments, sulfate- and iron-
reducing bacteria convert inorganic mercury to more bioaccumulative
and toxic methylmercury (MeHg). MeHg biomagnifies in higher
trophic level fish, posing a health risk to fish-consuming humans and
wildlife. In the Sacramento Valley, the conjunction of over 500,000
acres of paddy rice and other anoxic wetlands with mercury-
contaminated soils enhances production of MeHg. This study sought
to quantify the contribution of rice in the Sacramento Valley to MeHg
entering the Delta through a meta-analysis of published MeHg
concentration data from 1996-2007. The analysis focused on sample
sites on agricultural drainage canals, and on the mainstream
Sacramento and Feather Rivers immediately upstream and
downstream of agricultural drainages. All sites showed lower MeHg
concentrations from June through October, and higher, more variable
MeHg concentrations November through May. The period of low
MeHg concentrations roughly corresponds to the rice growing season,
while rice fields are flooded to promote straw decomposition during
the more-variable winter period. Agricultural drainage canals had
higher MeHg concentrations than sites on the Sacramento and
Feather Rivers during both summer and winter seasons. While load
estimation was limited by gaps in flow data and low temporal
sampling density, load estimates supported patterns found in
concentration data, with larger loads from agricultural drainages
occurring during the winter season. These results suggest that rice
may be a source of MeHg to the Sacramento River. However,
comparison to a recent field-scale study in the Yolo Bypass shows
that the contribution of rice to MeHg in the Sacramento River at a
basin scale may be much lower than field scale measurements would
suggest. Future research efforts should seek to reduce the overall
contribution of rice to MeHg in the Sacramento River, particularly
during the seasonal period of higher MeHg concentrations and loads.
21
FIELD TOURS OF RESEARCH
RICE VARIETY DEVELOPMENT
The RES breeding program consists of four research projects. Three
rice breeding projects focus on developing adapted varieties for
specific grain and market types and are each under the direction of a
RES plant breeder. The rice pathology project, under the direction of
the RES plant pathologist, supports the breeding projects through
screening and evaluating varieties for disease resistance, rice disease
research, and quarantine introduction of rice germplasm for variety
improvement. All projects also linked with the DNA marker
laboratory and are involved in cooperative studies with other
scientists from the UC, USDA and industry, including off station field
tests, nurseries, quality research, and biotechnology. Brief highlights
of the RES breeding program are discussed here and will be
presented during the field tour of the breeding nursery.
Medium Grain
(V.C. Andaya, Plant Breeder, RES)
Medium grain varieties developed at the Rice Experiment Station,
commercially known as Calrose, are the predominant type of rice
grown in California. Calrose varieties are estimated to be planted to
more than 90% of rice acreage in the state, three of which, M-206, M-
205, and M-202, are widely grown early maturing Calrose varieties
planted by CA rice farmers. M-206 has superior grain and milling
yields and better cold tolerance while M-205 registers superior grain
yields in the warmer areas of the Sacramento Valley. Acreage of M-
202 is rapidly declining in favor of the better milling and higher
yielding varieties, M-205 and M-206, and some very early varieties.
In 2011, RES released a very early maturing, semi-dwarf, glabrous,
high-yielding Calrose variety, M-105, as an alternative for cooler rice
growing areas where M-104 is commonly grown or where very early
varieties are desired. Its days to heading and yield performance are
in between M-206 and M-104. Resistance to cool temperature-induced
blanking, however, is not better than M-104. This new variety has
22
superior milling yield and stability, better than M-206 milling yields
even when harvested at lower harvest grain moisture. Based on rice
growers’ feedback and reports during the 2013 planting season in
Butte County, M-105 is competitive with the more popular Calrose
varieties and is superior to M-104 in yield and agronomic
performance. It is planted to approximately 14% of BUCRA’s rice
acreage, achieving head rice yield of more than 68%, outperforming
M-205, M-206 and M-104.
At RES, the breeding goals in the Calrose project are focused on the
development of varieties with high and stable grain yield, high
milling yield with excellent grain quality, cold tolerance, and disease
resistance. In the last several years, the project concentrated its
efforts in breeding and pyramiding new sources of blast resistance.
Mutation breeding is also used to find new variants with early
flowering, tolerance to certain herbicides, and improved overall plant
type. Moving forward, the project is taking serious steps to further
improve the grain quality and cooking attributes of Calrose to match
changing international market preference for better tasting rice while
still aiming for highest possible grain yields.
08Y3269, A high-yielding line
The advanced line 08Y3269 is a semi-dwarf, early maturing,
glabrous, and high-yielding Calrose advanced line is in the final
stages of evaluation and will be considered for release in 2015. It was
derived from a cross made in 2004 designated as R29174 with the
pedigree “M-205/3/90Y63/M-202//M-204”. It was first entered in
UCCE Statewide Test (SW) in 2010 and has undergone series of seed
purification in head row nurseries since 2012.
In 2014, a proposal for Foundation Seed increase of 08Y3269 was
submitted and approved by the CCRRF Board of Directors in
accordance with the RES Variety Release Policy and Protocol. If
released, this line may serve as an M-205 or M-202 replacement or
alternative. 08Y3269 is not recommended in areas where M-205 is
not successfully grown such as in cooler rice areas. 08Y3269
performed very well in the statewide yield tests, out-yielding M-202,
M-205, and M-206 by 8%, 6%, and 2%, respectively, using the 4-year
grain yield average. This entry performed best in Butte and Colusa
counties compared to M-205. It heads two days earlier than M-205,
with similar seedling vigor and plant height. In 2013, 08Y3269 was
entered in strip trials in Butte, Glenn, and Colusa where milling
samples were taken and evaluated. Milling yields, in terms of head
23
rice and total milled rice recovered, were similar to M-205 and M-206,
but may slightly drop if harvested at lower moisture levels. 08Y3269
has slightly larger kernels but has less chalky grains compared to M-
205 and M-206. 08Y3269 has better stem rot resistance score but has
no noticeable advantage to the other medium grain varieties in terms
of resistance to rice blast.
Disease Resistance
Stem rot and rice blast diseases are two of the more important rice
diseases in California. In response to the potential breakdown of
resistance in M-208, the medium grain project concentrated efforts in
breeding and pyramiding blast resistance genes that are effective
against the new blast race. In 2005, a backcrossing project was
initiated to introgress different blast resistance genes (Pi genes) into
M-206 background. Breeding lines were selected and advanced using
DNA markers linked to these genes, and the end-result were 10 near-
isogenic lines (NILs) of M-206 containing individual Pi genes. Stable
and uniform NILs were entered in preliminary yield tests to examine
if there are yield penalties and agronomic differences between these
isolines and M-206. Compared to M-206, agronomic performance and
grain characteristics varied depending on the resistance gene
introgressed.
Seven of these near-isogenic lines were entered in statewide test in
2013 and repeated in 2014. In 2013, 12Y113 (containing the Pi-z5
gene) yielded better than M-208 with an average yield of 9,600
lbs/acre. A notice of experimental increase was submitted for 12Y113
and the line is currently being purified in head rows.
Stem rot resistant lines that recovered the medium grain type of M-
206 were isolated from the stem rot resistance mapping project
spearheaded by Dr. Cynthia Andaya and Mr. Jeff Oster. Several of
these lines were entered in small plots for yield and agronomic
performance evaluation. Preliminary evaluation showed that few
stem rot resistant selections are significantly better in terms of
resistance scores compared to the M-206 but they still are later
maturing and low yielding. Resistant lines will be evaluated further
and will be used as parents for further crossing work.
Mutation Breeding
The Calrose project is continuously searching and evaluating traits
that may add value to rice varieties developed for California through
mutation breeding using chemical mutagens (EMS) and ionizing
24
radiation (gamma rays). By generating mutant populations derived
from M-202, M-205, M-206, M401, and other varieties, mutants were
isolated that are short, early maturing, and perhaps with tolerance to
certain herbicides. Generation of mutants and screening protocols are
currently handled by Dr. C. Andaya.
In previous years, early M-401 mutants were isolated from EMS-
treated seeds in the initial chemical mutagenesis experiment in 2010.
The mutants were purified and confirmed through DNA markers to
be true mutants of M-401. All the mutants identified are significantly
earlier maturing than M-401, but showed variation in terms of grain
quality, agronomic performance and eating quality. A high degree of
asynchronous heading that appeared to affect milling yields were
observed. Mutants were cross backed to M-401 for genetic analysis
and were also crossed to other early varieties for allelism testing.
Selected early M-401 mutants are entered in 2014 Statewide yield
test and will be further tested for grain and eating quality. Early
mutants of M-202 were also isolated and being tested in yield plots.
Premium Quality and Short Grain
(S. O. P.B. Samonte, Plant Breeder, RES)
Introduction
The Premium Quality and Short Grains Project encompasses the
improvement of the following rice varietal types:
• Short grain, premium quality (SPQ)
• Medium grain, premium quality (MPQ), and
• Short grain, conventional (SG)
• Short grain, waxy (SWX)
• Short grain, low amylose (SLA)
• Arborio or bold grain (BG)
All new lines are bred and selected for improved and stable grain
yield and yield-related traits, milling and cooking quality, reduced
delay in maturity and blanking due to cold temperature, lodging
resistance, very early to early and uniform maturity, and resistance
to diseases. In addition, there are specific trait parameters that are
selected to qualify a line into a specific grain type. Experimental lines
in nurseries and yield tests are compared against check varieties,
which include S-102 for SG types, Calamylow-201 (CA-201) for SLAs,
25
Calmochi-101 (CM-101) for SWXs, Calhikari-202 (CH-202) and
Koshihikari for SPQs, M-402 and M-401 for MPQs, and 87Y235 for
BGs. Selected lines must show improvements over their respective
checks.
Varieties and Elite Lines
Premium Quality Short Grain: Calhikari-201 and Calhikari-202
Calhikari-202, which was released in 2012, has continued to show its
yield advantage over CH-201 (released in 1999). In the Statewide
(SW) Tests conducted from 2010 to 2013, CH-202 had higher grain
yields than CH-201 in 26 out of 42 test environments, for a 4-year
average of 8,621 lb/acre, which was 4% higher than that of CH-201
(8,278 lb/acre). Based on the 42 test environments, CH-202 was the
higher yielder more frequently in RES, Yolo, and Yuba test locations,
CH-201 was the higher yielder more frequently in San Joaquin and
Colusa test locations, while both varieties were higher yielders on
equal occasions in Sutter, Butte, Glenn, and west Sutter test
locations. Head rice percentage averaged 64% across 2012 and 2013
for both CH-202 and CH-201.
This year, 3 elite SPQ lines are being evaluated in preliminary group
of the SW Tests. Among these, 12Y2167 was noteworthy because of
its higher yield, lower lodging, less blanking, and lower chalkiness
compared to checks CH-201 and CH-202.
Premium Quality Medium Grain: M-401 and M-402
M-401 and M-402, estimated grown in about 6.9 and 0.8% of the rice
acreage in California (http://www.crrf.org/ccrrf_res-v38_026.htm),
respectively, are the standard premium quality medium rice grain
varieties. Based on the SW Tests in 2012 and 2013, their average
grain yields were 8645 and 8238 lb/A, respectively, while head rice
were 59 and 67%, respectively.
This year, there are 8 advanced MPQ lines that are being evaluated
and compared against M-401 and M-402 in the SW Tests. Among the
MPQ lines, 11Y2183 has been outstanding. When averaged across
2012 and 2013, 11Y2183 yielded 9480 lb/acre, which was 15 and 10%
higher than M-402 and M-401, respectively. Compared to M-402 and
M-401, 11Y2183 had higher whole milled rice yield, similar seedling
vigor, earlier heading, less chalkiness, and better taste. MPQ
11Y2183 is undergoing purification and experimental seed increase
this year.
26
Conventional Short Grain Rice: S-102
S-102 is a very early maturing conventional SG variety. In the SW
Tests, its average grain yield (across 2011 to 2013) was 8470 lb/acre.
This year, there are 5 advanced SG lines that are being evaluated in
the SW Tests. SG 09Y2179 showed outstanding performance among
the SG lines. When averaged across 2011 to 2013, 09Y219 yielded
9690 lb/A, which was 14% higher than S-102. Furthermore, when
compared to S-102, 09Y2179 had higher whole milled rice yield,
higher head rice percentage, more days to heading (it is classified as
an early maturing line, unlike the very early maturing S-102), less
lodging, and better resistance to sheath spot. In addition, SG
09Y2179 has a glabrous grain compared to the pubescent S-102. SG
09Y2179 is undergoing seed purification and experimental seed
increase this year.
Waxy Short Grain Rice: Calmochi-101
Calmochi-101 (CM-101), the current standard SWX variety is
estimated to be grown in approximately 3.5% of rice acreage in
California (http://www.crrf.org/ccrrf_res-v38_026.htm). However,
varietal improvements in SWX rice are necessary especially for grain
yield. This year, the SG project is evaluating 4 advanced SWX lines in
the SW Tests, with SWX 09Y2141 being grown in all SW test
locations. SWX 09Y2141 is high yielding, semi-dwarf, early-maturing,
and glabrous. In comparison to the CM-101, 09Y2141 had
significantly higher grain yield in all 27 SW environments that it was
tested in from 2010 to 2013. Test locations were at Butte, Colusa,
RES, San Joaquin, Sutter, Yolo, and Yuba. The yield advantage of
09Y2141 over CM-101 ranged from 17 to 39%. Overall, grain yield
(averaged across 27 environments) was 10,000 lb/acre for 09Y2141
and 7,860 lb/acre for CM-101. Furthermore, when compared to CM-
101, 09Y2141 was similar in seedling vigor, taller by about 3 cm, it
required two more days to reach heading, and lodged 3% more. SWX
09Y2141 had a higher head rice percentage at 65%, larger grain size
dimensions, and lower viscosity when cooked. Blanking, which was
based on the San Joaquin Trials, was slightly higher in 09Y2141 than
CM-101. In 2013, some comments from the external evaluations on
cooking quality indicated that 09Y2141 was softer than CM-101, and
that it may be useful for soft Mochi such as Raw Mochi and Wagashi,
Japanese traditional confectionery. SWX 09Y2141 was purified in
isolated water-seeded headrows in 2013, and it is being grown in the
foundation seed increase field and headrows this year. The SW Tests
have shown that 09Y2141 is superior to CM-101, which was released
in 1985.
27
Low Amylose Short Grain Rice: CA-201
Calamylow-201 (CA-201) is the current SLA variety. However, its low
grain yield and high lodging percentage are unattractive traits that
need improvement. This year, 12 advanced SLA lines are being
evaluated in the Preliminary Yield Tests (PYT) at RES. Selections
that pass the PYT are advanced to the SW Tests.
Arborio or Bold Grain Rice
Arborio or bold grain rice types are grown on a small acreage in
California. RES has not released a BG variety, but it has released
87Y235 as a germplasm in 1994. The development of improved BG
lines is the first step to increase interest in this type of rice.
Currently, three advanced BG lines are being evaluated in the PYT at
RES.
Breeding for Disease Resistance
Reactions to stem rot, aggregate sheath spot, and blast by breeding
lines of the SG project that are entered into the PYT and SW Tests
are evaluated by RES pathologist Jeff Oster. In 2013, medium grain
lines pyramided with blast resistance genes by the Medium Grain
Breeding Project of Dr. Virgilio Andaya were used as parents in
crosses with lines and varieties of the Short Grain Breeding Project.
Marker-assisted selection for blast resistance in the resulting F2 and
F3 plants is being conducted in cooperation with Dr. Cynthia Andaya.
Long Grains
(Farman Jodari, Plant Breeder, RES) The objective of the long grain project is to develop superior
conventional long-grain and specialty long-grain varieties for
California. Main emphasis in the conventional (southern) long-grain
breeding category includes superior cooking quality, yield potential,
milling yield, milling yield stability, cold tolerance, seedling vigor,
and disease resistance.
L-206
This very early to early maturing semi-dwarf, conventional long-grain
variety was released in 2006. L-206 has shown improved cooked grain
texture and higher grain yield over earlier varieties. Average
heading date in 2014 statewide test at RES was 1 day earlier than
28
M206. Plant height is 11 cm shorter than M-206. L-206 has slightly
stronger amylographic profile, as shown by higher cool paste viscosity
and RVA setback values. Consequently cooked grain texture of it is
less sticky than L-204. Similar to Southern long grain, L-206 has
intermediate amylose and gelatinization temperature types.
L-206 is adapted to most rice growing areas in California except the
coldest locations of Yolo and San Joaquin counties. Average grain
yields of L-206 during 2006 to 2013 early statewide trials (RES,
Butte, Colusa, Yuba), was 9510 lb/A, as compared to 9380 for M-206.
Average head rice yield of L-206, however, is 62 %, which is 3% lower
than M-206. Fissuring studies indicate that L-206 is significantly
more resistant to grain fissuring than L-204, indicating a better
milling yield stability at lower grain moisture contents.
Results of a comprehensive study in 2012 sponsored by USA Rice
federation and conducted by Southern US experiment stations and
commercial milling companies have indicated that L-206 is highly
favored for packaging quality. Results indicated that L-206 was
ranked 1st among all US long grain varieties and hybrids for package
quality by the participating rice mills. The evaluation criteria that
were used included bran streaks, chalk, kernel color, uniform length,
and overall appearance. Concerted effort continues in the long grain
project to maintain and further improve the marketability qualities of
advancing long grain breeding material.
Among promising experimental long grain lines that are being tested
in 2014, entry 11Y1005 have shown excellent agronomic and quality
traits. Detailed performance of this line is included in RES annual
reports (http://www.crrf.org). In 2012 and 2013 very early statewide
tests average yield of 11Y1005 was 475 lb/A higher than L-206.
During the same period, 11Y1005 showed 2% higher head rice yield.
Cooking quality and grain appearance of these lines are similar to L-
206. Purification of 11Y1005 is currently underway. Currently this
line is being tested in all 8 of the statewide test locations.
The genetic base of long grain breeding material at RES has been
significantly expanded in recent years through the use of germplasm
from Southern US and world collection sources. This diversity is
being used to incorporate the desirable agronomic and quality traits
in the elite RES lines.
29
Specialty Long Grain
Breeding efforts continue in an accelerated pace, as market demand
for these types continues to increase. Currently, efforts are underway
to develop soft cooking aromatic jasmine, elongating aromatic
basmati, and conventional long-grain aromatic types adapted to
California. Specialty long grains currently occupy nearly half of the
long grain breeding nursery.
Calmati-202
This early maturing basmati type variety was released in 2006.
Quality improvements in this variety include more slender kernels,
higher cooked kernel elongation ratio, and more flaky grain texture.
Similar to Calmati-201 (CT-201) this variety is adapted to warm
growing areas. Grain yield of Calmati-202 (CT-202) has averaged
6740 lb/acre, which is 74% of M-202 yield potentials. Head rice yield
recovery of this variety is considerably lower than standard varieties
due to its slender grain shape, averaging 58%. It has a semi-dwarf
pubescent plant type with good seedling vigor. Maturity is similar to
CT-201 at 93 days to 50% heading. Milled kernels of this variety are
longer and narrower than CT-201 but not as slender as imported
basmati. Grain fissuring studies have shown that CT-202 is
susceptible to fissuring at low harvest moistures. Timely harvest and
proper handling is recommended to preserve milling as well as
cooking qualities of this variety. Due to slender grain shape and
pubescent hull and leaf, drying rate of the grain at harvest is
significantly faster than standard varieties. Recommended harvest
moisture is 18 to 20 percent.
A new series of basmati lines have been developed, including 5
entries that are currently being tested in 2014 statewide trials. These
lines have shown cooking qualities that are nearly indistinguishable
from imported basmati types. Grain and milling yields of these lines,
however, seem to be similar to or lower than CT-202. Current
breeding efforts are directed toward increasing both grain yield and
milling yield while maintaining their basmati quality traits. Their
adaptability thus far is limited to warmer rice growing region.
Efforts have significantly increased in jasmine type breeding and
currently occupy the largest section of the specialty nursery.
Conventional pedigree and mutation breeding methods are being
used. Jasmine type germplasm lines from southern breeding
programs and foreign introductions including the original Thai
Jasmine variety, ‘Khao-Dawk-Mali 105’, are being utilized. In 2014
30
statewide tests, 8 jasmine type selections are being tested. One entry,
11Y106, is currently being produced as headrow. It has shown good
cooking qualities with soft cooking texture and strong aroma.
Samples will be presented to marketing organizations in 2014 for
inputs regarding it market acceptability.
Quality testing was further expanded in 2013 for all advanced long
grain selections including conventional as well as specialty types.
Screening for amylographic profile through RVA was nearly doubled.
This is in an effort to match the cooking quality of conventional,
jasmine and basmati types to those of the current market.
Aromatic Experimental 11Y1049
This conventional cooking type aromatic line was released in January
2014, as variety ‘A-202’. This variety is intended to be a replacement
for the aromatic variety A-301. A-202 is early maturing, semi-dwarf,
and glabrous. Compared to A-301, A-202 is 9 days earlier, 4” taller,
and has significantly higher seedling vigor score. Average yields, in
lb/A in 2012 and 2013 ‘early’ statewide tests was 9100 and 7300 for A-
202 and A-301, respectively. Average headrice yields during the same
period were 60% and 53% for A-202 and A-301, respectively. Milled
kernels of A-301 are slightly bolder than A-301. The recommended
ratio of water to rice for cooking of A-202 is 2 to 1. Amylose content,
gelatinization temperature type and amylographic profile are similar
to A-301. Aroma volatilization of A-202 is slightly less during cooking
process. Flavor sensory of this variety, however, is similar to A-301.
Preliminary tests conducted in 2012 have also shown that under
organic production system A-202 has considerable yield advantage
over A-301 variety. A-202 is susceptible to cold induced blanking and
not recommended for production in cold locations. Areas of adaptation
for A-202 include Butte, Yuba, Colusa, Glenn, and Sutter Counties.
Stem Rot
Resistance breeding efforts continues in cooperation with RES plant
pathologist. The Oryza rufipogon source of resistance has been
incorporated to various long grain backgrounds. Majority of these
lines are early maturing and possess good level of cold tolerance.
Stem rot resistant experimental lines such as 10Y1008 continue to
produce consistently very high grain yields within the long grain
nursery. Milling quality improvement of these lines is currently the
primary breeding objective.
31
Rice Pathology
(J.J. Oster, RES)
The primary focus of the project is to facilitate the development of
improved disease resistance for the breeding projects by developing
and applying screening techniques to measure and score breeding
lines for selection, advancement, and data on breeding lines. This is
done by producing inoculum in the lab and managing disease
nurseries for optimal disease development. All advanced entries (646
entries, 2041 rows this year) in yield trials are evaluated for
susceptibility to stem rot in the field and aggregate sheath spot in the
greenhouse. Several years of testing are required to accurately
characterize the level of resistance in these entries.
The pathology project handles rice germplasm requests by the
breeders which must go through quarantine. All seed imported from
other countries is treated according to a permit issued by the USDA
and subject to inspections by CDFA to prevent introduction of new
pathogens/pests into California. Materials are then released for use
in the breeding program. This quarantine procedure ensures that the
breeders have access to traits important to the continuing
improvement of California varieties. In 2010, seven entries with cold
tolerance were introduced through quarantine.
M-208, was released in 2005, and gets its resistance from the major
gene, Pi-z. Major genes for disease resistance largely prevent
development of disease lesions on resistant rice. M-208 is resistant to
the IG-1 race found in California when the blast disease was first
found in California in 1996-7. In 2010, blast lesions were found on M-
208. Incidence was low (about 1 in 10000 plants was infected). The
blast fungus was isolated from these lesions. Inoculation tests on
differential varieties (varieties with different resistance genes) show
that not all the isolates are the same pathogenically, and that new
race(s) (pathotypes) now exist in California. One of these races can
defeat Pi-z and Pi-km/Pi-kh genes, even though Pi-k is not present in
any RES varieties. This race is similar to IB1. DNA tests at UC
Riverside on a different set of isolates taken from M-208 as well as
the original IG-1 isolates show that all the isolates have similar DNA
banding patterns (the isolates belong to the same lineage).
Worldwide, lineages often contain several pathotypes. So far, the IB1
race has not increased in frequency. It remains to be seen whether
these new races will spread and become more common. Additional
32
tests with IG-1 race isolates showed that M-208 is still resistant to
these isolates.
A backcrossing program started in 2005 has been completed after
seven backcrosses from donors with 10 different resistance genes into
M-206. These lines are very similar to M-206, but with a blast
resistance gene. The breeders have observed these lines in the field
and brown rice in the lab, and are being used in crossing. Many of
them yield more than M-208 and as much as M-206. They have also
been screened against sheath spot and stem rot, but are susceptible
to these diseases.
A similar backcross program was started in 2005 to transfer stem rot
resistance derived from Oryza rufipogon 100912 and O. nivara
105316 into M-206. Both long and short grain high yielding resistant
lines were used as donors in this transfer. Advanced generation
materials from each backcross level are screened in the field, where
the breeders can view resistant materials. Stem rot resistant
advanced generation materials were cross-screened against aggregate
sheath spot in the greenhouse. The result is lines with resistance to
both diseases. This material has been turned over to the breeding
projects. Currently, environmental effects and the need for multiple
years of testing greatly slow selection for disease resistance. A few
lines yielded as much as M-206 in 2013. Therefore, mapping
populations have been developed for both sources of resistance. Drs.
Virgilio and Cynthia Andaya are analyzing these populations to
develop markers for use in selecting for stem rot resistance. This
technology could allow for selection of resistant materials in early
generations and allow faster identification of resistant materials.
Finally, sheath blight resistance was found by southern researchers
in Jasmine 85, Te Qing, and MCR10277. Sheath blight is similar to
the aggregate sheath spot disease we have in California. There are
reports of dominant, single gene resistance in Jasmine and Teqing,
with the resistance gene being different in each variety. QTL studies,
however, indicate some genes in common, and some genes differing
between resistance sources. MCR10277 resistance is reportedly due
to 2 recessive genes. These three varieties are also resistant to sheath
spot. Unfortunately, Jasmine 85 and Te Qing are of the indica race,
which does not breed well with the japonica race grown in California.
A backcross program similar to that being followed for SR was started
in 2005 and is has been used to transfer this resistance into M-206
and L-206. Advanced generations from each backcross level have also
33
been screened against stem rot. A few lines have resistance to both
diseases. This material is now being turned over to the breeding
projects.
Preliminary data from Louisiana researchers found a major
resistance factor to sheath blight and that it is also present in the
stem rot and sheath spot resistant materials. Markers are available
to detect this factor. Eventually, molecular markers may be used to
detect resistance to all three diseases, greatly facilitating production
of the resistant varieties of the future.
Virgilio “Butz” Andaya is Director of Plant Breeding & Medium-Grain
Project Leader, Farman Jodari Long-Grain Project Leader, Stanley O.
P.B. Samonte is Premium Quality & Short-Grain Project Leader, Jeff
Oster is Rice Pathologist, and Cynthia Andaya, is Research Scientist
(DNA Lab) at RES.
34
Fifteen Years of Pyrethroid Insecticide Use in Rice
– Are These Products Still Effective? Are There
Viable Options Nearing Registration? What Is the
Future of IPM of Rice Invertebrate Pests?
(L. D. Godfrey, K. Goding, and M. Aghaee, and L.
Espino, UCCE and UCD)
Pyrethroid insecticides were registered for use in rice in California in
1999 with lambda-cyhalothrin being the initial product to market
quickly followed by (S)-Cypermethrin. These products, along with
Dimilin (diflubenzuron), replaced carbofuran that was phased out of
the market due primarily to non-target concerns. Over the last 15
years of use, pyrethroids now get about 99% of the insecticide use in
California rice.
The switch to pyrethroids in rice required a new management
approach compared with the use of carbofuran. Following a brief
learning curve in the late 1990’s to early 2000’s, the industry learned
how to best use these products and the cost:benefit ratio of these
applications has been excellent. Carbofuran primarily targeted the
larval stage of the rice water weevil whereas the pyrethroids provided
control by killing the adults thereby preventing oviposition and the
occurrence of the larval stage. Missing the window of application for
the pyrethroids resulted in very poor control so appropriate timing
was critical.
After 15 years of use in rice are the pyrethroids still effective, viable
products? Insecticides can be lost from the marketplace due to
regulatory and biological aspects. Pyrethroid insecticides are very
toxic to non-target organisms. However, the industry has been very
careful and diligent to prevent off-site application/movement of these
products and the concerns in this regard have been mitigated. The
California Department of Pesticide Regulation (DPR) started a
reevaluation of certain pesticide products containing one or more
pyrethroid active ingredients on August 31, 2006. This was primarily
done because monitoring surveys and toxicity studies revealed the
widespread presence of synthetic pyrethroid residues in the sediment
of California waterways at levels toxic to certain indicator aquatic
species. Additional data were required to address this topic/concern.
During the process of this evaluation, it was determined that there
was limited data on urban offsite movement compared to agricultural
35
use patterns. In July 2012, DPR put into place regulations designed
to reduce runoff from outdoor residential use of pyrethroids and this
reevaluation concluded in May 2014. DPR will continue to monitor
and address agricultural and indoor use patterns of pyrethroids, if
needed.
Insecticide resistance is a biological process that can compromise the
usefulness of insecticides. The dependence on the pyrethroid class of
chemistry in the rice system is one factor which could promote the
build-up of resistance. Reports from PCAs the last few years have
suggested the efficacy of the pyrethroid products may not be to the
level seen in previous years. In 1999, the susceptibility of rice water
weevil to lambda-cyhalothrin was determined via a laboratory
bioassay method. This was before this active ingredient had been
used to any extent for rice water weevil control. This same
evaluation was done in 2013 from weevils collected in Butte Co. and
these weevils were equally susceptible to lambda-cyhalothrin as in
1999. Therefore, there was no evidence of the build-up of resistance.
Although based on regulatory and biological aspects, pyrethroid
products are still viable and useful products, it is unwise to
completely rely on one class of chemistry for managing invertebrate
pests in rice. Resistance can “appear” quickly and regulations can be
imposed based on “new science” or public pressure quickly changing
the availability of products. Staying current and adopting the newest
and most advanced management tactics also has merit along with, as
much as possible, keeping up-to-date with the other rice producing
states.
Belay® (clothianidin) was registered for use in the 2014 rice season in
California. For rice water weevil control, research has shown that
this product is best applied at the 2 to 3 leaf stage. Control is from a
combination of effects on the adults as well as direct kill of the
damaging larval stage. There is also activity with a preflood as well
as a rescue (5 to 6 leaf stage application) but this control is not to the
level of the 2 to 3 leaf stage timing. As this product is used under
grower conditions, conditions, such as rate, timing, etc., needed to
optimize the cost-effectiveness can be fully determined. Our studies
have shown that this insecticide has minimal effects on other aquatic
non-target organisms. These are important components of aquatic
ecosystems as well as part of food webs that feed upon mosquito
larvae. Clothianidin is a neonicotinoid insecticide; this class of
insecticide has been suggested to be involved in the problems
impacting honey bee populations in recent years. However, use of
36
this active ingredient at the 3 leaf or earlier rice stage should
minimize exposure to bees as this is long before any floral attractants
are available for bees. Discussions with local apiculturists have
supported these ideas.
Coragen® (rynaxypyr) is another insecticide under development for
rice water weevil management. Our research has shown this
insecticide provides optimal rice water weevil management with a
preflood application. In the southern rice system, rynaxapyr is used
as a seed treatment and is highly effective against several insect
pests. However, in our water-seeded system, the seed treatment
application method has not been consistently effective. In contrast,
the preflood application of rynaxapyr is very effective.
Cruiser® (Thiamethoxam) is being evaluated extensively in ring plots
in 2014 as a seed treatment. This active ingredient is registered on
rice (including California) on dry-seeded rice. The performance
against rice water weevil on our more typical water-seeded rice is
being determined.
An environmentally friendly alternative biopesticide against rice
water weevil larvae has also been studied. This is based on the
bacterium Bacillus thuringienesis spp. galleriae (Btg). The Btg
granular formulation (Phy-4-12) performed as well as lambda-
cyhalothrin in greenhouse and field trials. Foliar formulations of Btg
applied after flooding were less effective.
With the upswing in tadpole shrimp populations in recent years and
the loss of the usefulness of copper sulfate in many areas, new
insecticides are needed for this pest. The products mentioned above
for rice water weevil, pyrethroids, Belay, and Coragen have activity
on tadpole shrimp but I would classify them as only moderately
effective. More active materials are needed.
Larry Godfrey is a UC Cooperative Extension Specialist and
Entomologist in the Agricultural Experiment Station, Department of
Entomology and Nematology, UCD; Kevin Goding is a Staff Research
Associate, Department of Entomology and Nematology, UCD;
Mohammad-Amir Aghaee is a Graduate Student Researcher,
Department of Entomology and Nematology, UCD, and Luis Espino is
a Rice Farm Advisor, Colusa Co, UCCE.
37
Rice Weed Control: Herbicide Programs, New
Chemicals, and Weed Management
(A.J. Fischer, W. Brim-DeForest, R. Alarcon-
Reverte, R. Pedroso, B.A. Linquist, C. Greer, L.
Espino, R.G. Mutters, Farm Advisor, Butte Co, J.E.
Hill, S. Johnson, and J.R. Stogsdill, SRA II, UCD
and UCCE)
Our field program includes the testing of herbicides, their mixtures
and sequential combinations for the rice growing systems that
currently prevail in California. At this years’ field day we will show
highlights of our weed control experiments conducted on the Rice
Experiment Station’s (RES) Hamilton Road field. Experiments in
2014 involved water seeded continuously flooded rice, early-drain
(pinpoint) systems, and drill seeded systems. In addition, our
research effort also includes areas in two cooperating grower’s fields
infested with multiple-herbicide resistant late watergrass (“mimic”)
and ALS-resistant sedges. We continue to test new products and to
assist the rice industry in the registration of new herbicides as
options become available. We have a strong emphasis towards the
diversification and sustainability of weed management in rice, thus
we continued work on the evaluation of different irrigation methods
and their impact on weed communities, as well as the development of
growth and emergence models, which will eventually be utilized to
create prediction tools for farmers to improve the timing of herbicide
applications. Our efforts seek to assist California rice growers in
their critical weed control issues of preventing and managing
herbicide-resistant weeds, achieving economic and timely broad-
spectrum control and complying with personal and environmental
safety requirements.
Here we highlight results from our 2014 field operation for the major
rice growing systems used in California. Efficacy comments mostly
reflect herbicide program performance by approximately 40 days after
seeding (DAS) rice, thus covering the critical period for weed control
in water-seeded rice determined at the RES.
Continuously flooded rice
This system intends to maximize weed suppression by flooding,
notably the elimination of barnyardgrass and sprangletop as
problems. After seeding into a flooded field, water depth is
38
maintained at 4 inches throughout the season. When late post-
emergence applications are needed, water is lowered to expose about
70% of weed foliage to the herbicide spray, but fields are never
drained. Watergrass (early and late) were the predominant weeds,
followed by ricefield bulrush, smallflower and ducksalad. All weeds at
our field site are susceptible, but we discuss and give herbicide
options for fields with both resistant and susceptible populations.
For control of multiple-resistant watergrass in locations with
susceptible sedge and broadleaf populations, an application of a tank
mixture of Abolish + Regiment (1.5qt/a + 0.53oz/a + 2.0% v/v UAN +
0.2% v/v NIS) at the 5 lsr (leaf stage of rice) provides good control.
Options for early sedge and susceptible grass control include Granite
GR alone (15lb/a) at the 2-3 lsr, or Cerano (day of seeding at12lb/a)
followed by Granite GR (15lb/a) or Butte (7.5lb/a at 1 lsr) at the 2-3
lsr. All three options provide excellent control of ricefield bulrush,
smallflower and ducksalad. The combination of Cerano followed by
Granite provided the best watergrass (susceptible) control (100%).
Butte is a good option for sites with ALS or propanil resistant sedge
populations.
Bolero is a granular into-the-water herbicide that can be used to
begin an herbicide program in which it helps with sprangletop
(although this weed should be uncommon in continuously flooded
rice) and with ALS-inhibitor and/ or propanil-resistant smallflower
umbrellasedge control. A program with Bolero applied at 23 lb/a at 1
lsr followed by Regiment (0.8oz/a at 3-4 lsr) provided good watergrass
and ricefield bulrush control (93%) and excellent smallflower
umbrellasedge control (100%). Regiment at the highest label rate is
an option for fields with multiple-resistant watergrass. In susceptible
watergrass fields, a good alternative is also to follow Bolero with
Granite SC + SuperWham (2oz/a + 6 qt/a + 1/25% v/v COC) at the 3-4
lsr. Watergrass control was good (92%), while ricefield bulrush,
smallflower umbrella sedge and ducksalad control were excellent
(100%). When Bolero was followed by SuperWham alone (6 qt/a +
1/25% v/v COC) at the 3-4 lsr, control of ricefield bulrush was also
good (96%), as was control of ducksalad (92%).
An alternative granular formulation to control susceptible sedges and
watergrass is Granite GR (15lb/a) at the 1 lsr followed by
SuperWham (6 qt/a + 1/25% v/v COC) at the 3-4 lsr. It provided 100%
control of sedges and ducksalad, and good grass control (97%).
39
Shark H2O is a good herbicide for a program aimed at controlling
ALS inhibitor- and/or propanil-resistant sedges (thus delaying the
evolution of resistance to those herbicides. Shark H2O alone into the
water (7.5oz/a) at the 1 lsr had good early control of bulrush (86%) but
late-emerging bulrush was not well controlled. Smallflower control
was good and lasted until 40 days after seeding (86%). Abolish +
Regiment (1.5qt/a + 0.53oz/a + 2.0% v/v UAN + 0.2% v/v NIS) at the 5
lsr provided 91% control of watergrass (this mixture is also good for
the control of multiple-resistant watergrass). Regiment at the 5 lsr
will also suppress resistant watergrass. When Cerano was applied
day of seeding (DOS) (12lb/a) followed by Shark H2O and then by an
Abolish+Regiment mixture, control of watergrass increased to 96%.
When Granite GR (15lb/a) and Shark H2O (7.5oz/a) were applied
together at the 2.5 lsr, control of all weeds was excellent (100%).
To increase control of ricefield bulrush for sites with heavy
populations, another option is to combine Shark H2O + Halomax
(7.5oz/a + 1.33oz/a) for in into the water treatment at the 2-4 lsr.
Control of both ricefield bulrush and smallflower was excellent
(100%) and the control of watergrass by Cerano (12lb/at DOS) was
enhanced by this mixture. Any escapes can be controlled with a
follow-up application of SuperWham at the 1-2 tiller stage (6qt/a +
1.25% v/v) (98% watergrass control).
Bolero and Cerano are two good options for early grass (watergrass
and sprangletop) control in a Shark H2O-based program in a
continuous flood. Bolero (23lb/a) applied at the 1 lsr had good
watergrass control (95%), as well as good ricefield bulrush and
smallflower control (80% and 96%, respectively). When Bolero was
followed by Shark H2O + Halomax (7.5oz/a + 1.33oz/a) at the 2-3 lsr,
control of sedges increased to 98%. Cerano (10lb/a) at DOS alone
controlled 92% of watergrass; when followed by Shark H2O +
Halomax (7.5oz/a + 1.33oz/a) at the 2-3 lsr, watergrass control
increased to 99%. Sedge and broadleaf control was excellent (100%).
Stand reduction was a problem in the Bolero-based treatments.
Early drained water-seeded rice
Often, cold weather or windy conditions in spring require early field
drainage to favor rice establishment. Also, fields are often drained
for use of foliar-acting early post-emergence herbicides.
40
Pinpoint flood
In this experiment weeds were controlled by foliar herbicide
treatments applied during a period of field drainage for good weed
exposure to the herbicides. Prevailing weeds were early and late
watergrass, ricefield bulrush, sprangletop and ducksalad.
A tank mix of Clincher + Granite SC (13oz/a + 2oz/a + 2.5% v/v COC)
at the 3-4 lsr provided good control of sedges and excellent control of
sprangletop (100%). For sites with multiple-resistant watergrass, a
follow-up of Abolish + Regiment (1.5qt/a + 0.53oz/a + 2.0% v/v UAN +
0.2% v/v NIS) or Regiment (0.8oz/a + 2% v/v UAN + 0.2% v/v) at the 1
tiller stage of rice provides control of watergrass escapes. A 3-way
tank mix of Clincher + Granite SC + Abolish (13oz/a + 2oz/a + 1.5qt/a
+ 2.5% v/v) showed comparatively reduced efficacy on the sedges (89%
control of ricefield bulrush and 95% control of smallflower), and
sprangletop (81%).
For sites with susceptible sedge and grass populations, there are
several good programs. Regiment (0.67oz/a + 2% v/v UAN + 0.2% v/v
NIS) at the 3-4 lsr followed by SuperWham + Clincher (6qt/a + 13oz/a
+ 2.5% v/v COC) at the 1 tiller stage of rice provided excellent broad-
spectrum control. Clincher (13oz/a + 2.5% v/v COC) at the 3-4 lsr
followed by SuperWham + Grandstand (6qt/a + 8oz/a + 1.25% v/v
COC) provided excellent watergrass and sprangletop control (96%
and 100%, respectively) and good ricefield bulrush and smallflower
control (94% and 80%, respectively). Granite SC (2oz/a + 1.25% v/v
COC) followed by SuperWham + Clincher (6qt/a + 13oz/a + 2.5% v/v
COC) controlled watergrass (99%) and sprangletop (100%). Efficacy
on sedge and broadleaves was excellent (greater than 97%). As in
previous years, a tank mixture of Clincher and SuperWham (13oz/a +
6 qt 2.5% v/v COC) at the 3-4 lsr provided good broad-spectrum
control of all weeds except for broadleaves, but the antagonism
between the two herbicides lowered their efficacy slightly (control of
sprangletop was only 75%).
Drill seeded rice
This is the system that offers flexibility for herbicide use when
proximity to sensitive crops imposes restrictions to aerial
applications. Drill seeding favors weeds adapted to dryland seedbeds
(sprangletop is typically problematic, as are barnyardgrass and
smallflower umbrella sedge) and is less favorable for aquatic species
(ricefield bulrush, ducksalad, and redstem). Thus dry seeding is
useful for alternation with water-seeded systems when the pressure
41
of aquatic weeds becomes problematic. Main weeds in the experiment
were the Echinochloa complex, sprangletop, and some smallflower
umbrella sedge. Before heading, the Echinochloa complex is difficult
to differentiate. Later weed ratings will determine the percentage of
one species versus another.
For early weed control, some herbicides are applied before rice
emergence. For a delayed pre-emergence application, the field is first
drill seeded into dry soil. The field is flushed once, to moisten the soil
and imbibe the rice seed, and then a liquid herbicide is applied onto a
moist soil surface. Prowl (2 pt/a) is a pre-emergence herbicide that
can protect from weed emergence after seeding rice during the period
prior to the permanent flood. Abolish is another option as a pre-
emergence herbicide. Both herbicides should be active against
watergrass, barnyardgrass, and sprangletop; Abolish is more active
on smallflower umbrellasedge than Prowl. Prowl H2O (2pt/a) applied
alone at delayed pre-emergence (DPRE) provided only partial (34%)
Echinochloa suppression, 75% control of sprangletop and 85%
smallflower umbrellasedge control, indicating it is not a stand-alone
herbicide but that it can be a useful mixing partner to limit weed
emergence from soils (does not have foliar activity). Abolish (1.5 qt/a)
provided poor late watergrass control (only 5%) but better early
watergrass/barnyardgrass control (up to 76%) and controlled
sprangletop by 70%. Abolish alone in DPRE control smallflower
umbrellasedge by 93%. A follow-up application of a tank mixture of
Abolish and Regiment (1.5qt/a + 0.53oz/a + 2.0% v/v UAN + 0.2% v/v
NIS) provided excellent watergrass grass control (up to 95% of late
watergrass).
The tank mixture of Prowl H2O (2pt/a), SuperWham (4qt/a) and
Clincher (13oz/a) applied with 2.5% COC at the 2-3 lsr is a standard
mixture that controlled emerged grasses (94% control of late
watergrass, 61% control of sprangletop by 40 days after seeding rice,
DAS) and smallflower umbrella sedge (85% control by 20 DAS) while
Prowl suppressed the emergence of germinating weeds. The tank
mixture of Prowl H2O (2pt/a), Granite SC (2oz/a) and Clincher
(15oz/a) applied with 2.5% COC at the 2-3 lsr was another good
option, providing overall best grass control (99% watergrass control,
82% sprangletop control) although control of smallflower was poor
(47%) and would have required a follow-up application.
42
New Compounds
Wetcit® (crop oil based surfactant) By Oro-Agri
Under a continuous flood, SuperWham (6 qt/a) + Wetcit® (1.25% v/v)
applied at the 1-2 tiller stage of rice controlled watergrass (71%),
ricefield bulrush (93%), smallflower (100%) and ducksalad (74%).
When applied with a generic crop oil concentrate, at the same timing
and rate, control of watergrass, ricefield bulrush and ducksalad were
slightly lower (66%, 90%, and 58%, respectively).
RiceEdge® (dry flowable mixture of propanil and halosulfuron) by
RiceCo, LLC
RiceEdge® was tested under a continuous flood and a pinpoint flood
(drained for one week at the 3-4 lsr). In both trials, it was applied at
the highest label rate, of 10 lb/a (+ 1.25% v/v COC) at the 1-2 tiller
stage of rice. In the continuous flood, it controlled watergrass (68%),
and had excellent control of both ricefield bulrush and smallflower
(99% and 100%). In the pinpoint, the same rate and timing controlled
60% of watergrass, and had excellent control of ricefield bulrush and
smallflower (95% and 100%). Phytotoxicity was low (5% tip burn).
The mixture did not perform well when applied at a later timing (40
DAS).
League MVP® (granular mixture of thiobencarb and imazosulfuron)
By Valent
This year, we tested a new League MVP® formulation with a higher
concentration of both thiobencarb and imazosulfuron (11.67% +1%) in
comparison to the current commercial formulation (10% +0.43%).
Under a continuous flood, League MVP® (30lb/a) of the currently
commercial formulation applied into the water at the 1 leaf stage of
rice (lsr) fully controlled ricefield bulrush, smallflower and ducksalad.
Control of watergrass was excellent, at 98%. Applied at 30lb/a at the
2 lsr, the current commercial formulation continued to give excellent
broad-spectrum control, although phytotoxicity was higher than at
the 1 lsr (some stand reduction). The new formulation with 11.67%
thiobencarb +1% imazosulfuron, applied at the same rate (30lb/a) had
excellent control of the same weed species at both the 1 lsr and 2 lsr.
Higher stand reduction was observed with the higher percentage of
thiobencarb. For fields with multiple-herbicide-resistant watergrass,
a follow-up application of Regiment (0.8 oz/a) at the 1-2 tiller stage of
rice will improve control. At a later timing (3 lsr), both formulations
provided excellent control of watergrass (over 97%), ricefield bulrush
and smallflower (100%), though ducksalad control was lower than at
43
the earlier timings (58% in comparison to over 90%). Phytotoxicity
was low at the later application timing (3 lsr).
Butte® (granular mixture of benzobicyclon and halosulfuron) By
Gowan
Butte® was tested under a continuous flood, both alone and in a
program. Phytotoxicity on rice was very low. The granular
formulation of Butte (7.5lb/a) applied at the 1 lsr had good watergrass
control (97%) early in the season and excellent ricefield bulrush,
smallflower and ducksalad control. By 40 days after seeding,
watergrass control was 88%. Follow-up treatments applied at the 1
tiller stage helped maintain the early high level of watergrass control.
Thus SuperWham + Grandstand (6qt/a + 8oz/a+ 1.25% v/v COC),
Regiment (0.67oz/a + 2.0% v/v UAN + 0.2% v/v NIS), or Granite SC
(2oz/a + 1.25% v/v COC) provided 100% watergrass control. Redstem
control was best when Grandstand was used. Rice bleaching was high
and some stand reduction observed, but broad-spectrum weed control
was best with the sequence of Cerano (12lb/a) followed by Butte (7.5
lb/a) at 1lsr.
Weed Management
The evolution of herbicide resistance in major weed species of
California rice, including Cyperus difformis L. (smallflower
umbrellasedge) and Echinochloa phyllopogon (Stapf) Koss (late
watergrass), has necessitated the search for alternative management
options, including alternate herbicide modes of action and tillage
practices in conjunction with the use of a stale seedbed. In addition to
the prevailing water seeding and continuous flooding in rice, reduced
irrigation schemes are being explored for water conservation, which is
expected to alter the usual weed recruitment patterns.
Weed Germination, Emergence and Growth Models
To establish appropriate timing of weed control interventions under
variable field conditions, it is necessary to be able to predict the
dynamics of weed germination and emergence under those conditions.
Laboratory-generated models of germination and emergence for C.
difformis and E. phyllopogon have accurately predicted timing of
germination and emergence in controlled environments by
incorporating information about water potential and temperature
into population based threshold models (PBTM). The models use
hydro- and thermal- time (accrual above a base temperature and base
water potential) to predict population-level germination and
emergence events. Since the ultimate use of these models is to
44
facilitate better management decisions in the field, we are evaluating
them under field conditions. In 2013, observed values in the flooded
systems varied considerably from predicted (laboratory-generated)
values, particularly when comparing initiation of emergence and 90%
emergence. Predicted values of 90% emergence for C. difformis under
flushed conditions were 138 Growing Degree Days (GDD in °C d),
whereas under field conditions, the value was 145 GDD. 90%
emergence of E. phyllopogon under flushed conditions was predicted
to be 227 GDD, and the actual value was 323 GDD. Differences could
be due to a number of factors, including overwintering conditions in
the field, which may affect seed dormancy status differently than the
stratification conditions (wet-chilling) on which the laboratory models
were based. Fields were not flooded over the winter, which may have
resulted in the seeds not being fully imbibed at the onset of irrigation,
causing an increase in GDD in the field in comparison to laboratory
models. The observed differences in the flooded fields could also be
explained by slow emergence due to seedling growth inhibition under
anoxia. Our validation work continued in 2014.
Weed Population Dynamics in Alternative Irrigation Systems
Due to looming water resource issues in California, we have also been
evaluating the dynamics of weed emergence in alternative irrigation
systems. Since 2013, we have been evaluating three systems: i)
Water-Seeded Alternate Wet and Dry (WS-AWD): Flooded for initial
seeding by air, and until canopy closure of the rice, subsequently
allowed to drain and then flushed again when Volumetric Water
Content (VWC) reached 35%; ii) Drill-Seeded Alternate Wet And Dry
(DS-AWD): Drill-seeded, then flushed again when VWC reached 35%;
and iii) Water-Seeded Conventional (WS-Control): permanent flood of
10-15 cm, which was maintained until the field was drained
approximately one month prior to harvest. We will continue to
evaluate the system for at least 2 more years. Preliminary results
confirm earlier results from other dry- versus wet-seeded systems.
The dry-seeded system was dominated by grasses (particularly
barnyardgrass and sprangletop) with a small population of
smallflower umbrella sedge. The wet-seeded systems were dominated
by aquatic weeds: primarily ducksalad, ricefield bulrush, and some
watergrass. With full-control of weeds, yields were the same across
all systems (10 t/ha). Without weed control, yields in the dry-seeded
system were 0 t/ha. In the two water-seeded systems. yields were not
significantly different from each other; the WS-AWD yielded slightly
lower (5 t/ha) than the WS-Control (7 t/ha).
45
Herbicide Resistance in Smallflower Umbrella Sedge
Smallflower umbrella sedge (Cyperus difformis L.; CYPDI) is a
troublesome annual weed (Cyperaceae) commonly found in rice fields
worldwide. In CA, CYPDI management was complicated by the
evolution of resistance to acetolactate-synthase (ALS)-inhibiting
herbicides in 1993; ALS-resistant (R) CYPDI populations are now
widespread throughout CA rice fields. In the wake of resistance to
ALS inhibitors, the post emergent photosystem II (PSII)-inhibiting
herbicide propanil (3,4-dichlopropionanilide) has been extensively
used to control ALS-R CYPDI and other weeds of rice. Lack of proper
control following propanil spraying was detected in 2012 suggesting
resistance to this herbicide might have also evolved in rice fields. The
objectives of this research were to confirm resistance to propanil,
ascertain resistance levels, and establish the underlying mechanisms
of resistance in CYPDI biotypes collected in rice fields of California.
Our results indicate that a number of CYPDI populations collected in
CA rice fields displayed a high level of resistance to propanil (R/S
ratio equaled 14). When rice cv. M-206 and propanil-susceptible (S)
and –R CYPDI were sprayed with propanil jointly with the insecticide
carbaryl (a known propanil synergist that inhibits propanil
degradation in plants), all plant species except propanil-R CYPDI
experienced significant growth suppression, suggesting propanil
metabolism is not the mechanism of resistance in the R biotypes
used. Interestingly, propanil-R CYPDI biotypes are also cross-
resistant to other PSII-inhibiting herbicides (diuron, atrazine,
bromoxynil, and metribuzin), although resistance to atrazine is weak.
These results suggested propanil resistance might involve the PSII-
inhibitor binding site at the target protein D1 of PSII. Therefore, we
sequenced the herbicide-binding region of the chloroplast psbA gene,
which codes for propanil’s target site (e.g. the D1 protein), where a
valine to isoleucine substitution at amino acid residue 219 was
identified. This mutation had already been found in Poa annua
biotypes resistant to diuron and metribuzin and is not associated
with resistance to atrazine in agreement with our results. Therefore,
unlike resistance in grasses and selectivity in rice - at which
resistance is attributed to enhanced propanil degradation, resistance
to propanil in CYPDI from CA is endowed by a single mutation at the
D1 protein, which affects binding of propanil at its target-site. For
control of propanil-R CYPDI (and given the widespread resistance to
ALS inhibitors in CA rice fields), it is thus necessary to switch
herbicide modes of action away from PSII and ALS inhibitors, and
prevent spread of resistant populations by preventing seed
contamination by performing proper cleaning of tillage and harvest
46
machinery. Further research has also indicated that other herbicides
used in rice are effective against propanil-R CYPDI, such as
carfentrazone, benzobicyclon, and thiobencarb.
Herbicide Resistance in Sprangletop
Two subspecies of sprangletop (Leptochloa fusca spp. fascicularis and
Leptochloa fusca spp. uninervia) are native to California. Preliminary
surveys indicate that there are differences between the two
subspecies in their distribution: fusca is spread throughout rice fields,
and uninervia appears closer to the edges. Only a few herbicides are
available to control sprangletop in California. The two active
ingredients most widely used are clomazone (commercial names
Cerano, Bombard) and cyhalofop-butyl (Clincher). Clomazone is a
DXP synthase inhibitor, and cyhalofop-butyl is an ACC-ase inhibitor.
In the past two years, we received grower field-collected samples that
were tested for resistance (2012 and 2013) to these two active
ingredients. We confirmed independent populations with resistance
to clomazone and cyhalofop-butyl, but have no confirmed cases of
multiple-resistance. All samples tested and confirmed resistant are
from the spp. fusca, not spp. uninervia. Preliminary results indicate
that resistance to cyhalofop-butyl also confers cross-resistance to
quizalofop, but not to clethodim (also ACC-ase inhibitors). Further
research is needed to determine possible mechanisms of resistance.
Abolish (thiobencarb) and Prowl H2O (pendamethalin) used as pre-
emergent herbicides still offer good control in dry-seeded systems,
while Bolero (thiobencarb) offers control in water-seeded continuously
flooded systems.
47
Herbicides used and their active ingredient
% ai lb ai/gal
Abolish (thiobencarb) 84 8.0
Bolero Ultramax (thiobencarb) 15 NA
Butte (benzobicyclon + halosulfuron) 3+0.64 NA
Cerano (clomazone) 5 NA
Clincher (cyhalofop-butyl) 29.6 2.4
Granite SC (penoxsulam) 24 2.0
Granite GR (penoxsulam) 0.24 NA
Grandstand (triclopyr) 44.4 3.0
Halomax (halosulfuron) 75 NA
League MVP (thiobencarb+imazosulfuron) 10+0.43 NA
Londax (bensulfuron-methyl) 60 NA
Prowl H2O (pendimethalin) 42.6 3.8
Regiment (bispyribac-sodium) 80 NA
RiceEdge (propanil + halosulfuron) 60+0.64 NA
Sandea (halosulfuron) 75 NA
Shark H2O (carfentrazone) 40 NA
SuperWham (propanil) 41.2 4.0
Albert J. Fischer, Professor, Weed Science Program, Department of
Plant Sciences; Whitney Brim-DeForest, PhD Student; Rocio Alarcon-
Reverte, Post-doctoral fellow; Rafael Pedroso, PhD Student; Bruce A.
Linquist, Assistant Cooperative Extension Specialist, Department of
Plant Sciences; Chris Greer, Farm-Advisor, Yuba-Sutter Co.; Luis
Espino, Farm Advisor, Colusa-Glenn Co.; Randal G. Mutters, Farm
Advisor, Butte Co.; James E Hill, CE Specialist, Department of Plant
Sciences; Steve Johnson, SRA I; and J. Ray Stogsdill, SRA II, at UCD
and UCCE.
48
ACKNOWLEDGMENTS The generous support of the Rice Field Day and Rice Research
Programs by the following organizations and individuals made this
field day possible. We appreciate their cooperation and support.
FINANCIAL SUPPORT
Dow AgroSciences
Rue & Forsman Ranch Partnership
Farmer’s Rice Cooperative
Associated Rice Marketing Cooperative
K-I Chemical USA, Inc./Kumiai Chemical
California Rice Commission
RiceCo, LLC
R. Gorrill Ranch Enterprises
Koda Farms Milling, Inc.
USA Rice Federation
BUCRA
FMC Corporation
Gowan
ADM Rice, Inc.
American Commodity Company, LLC
California Agricultural Aircraft Association
SunFoods, LLC
Far West Rice, Inc.
AMVAC Chemical Corporation
Colusa Rice Company, Inc.
49
TRUCKS
John Taylor/Wilbur Ellis Company
BUCRA
Delta Industries
Helena Chemical Company
Big Valley Ag Services
PRODUCT/SUPPLIES
Biggs Farming Group (Straw Bales)
Butte County Mosquito & Vector Control District
Brandt (Copper Sulfate Crystals)
John Taylor/Wilbur Ellis Company (Cerano®)
FMC Corporation (Shark H2O®)
RiceCo (Super Wham®)
EQUIPMENT DISPLAY
Valley Truck and Tractor
Holt of California
SWECO