Extension, Research and Creative Activity

Extension, Research and Creative Activity

Section 1.Rice Productivity and Efficiency

1.1Rice Variety Adaptation and Cultural Practices

1.2Soil Fertility and Fertilizer Use in Rice

Section 2.RicePest Management

2.1Integrated Strategies to Manage Resistant Weeds and Reduce Herbicide Use in California Rice

2.2Occurrence and Management of Red Rice in California

2.3Impact and Management of Bakanae Disease

Section 3.Water Quality

3.1Development and Implementation of Cultural and Water Management Practices in Rice to Protect Downstream Water Quality

Section 4.Rice Production Workshop

4.1Cooperative Extension Rice Production Workshop

1.1 Rice Variety Adaptation and Cultural Practices (2004-2005)

Collaborators: Jim Hill (UCD Dept. of Plant Sciences), Cass Mutters (Butte Farm Advisor), Mick Canevari (San Joaquin Farm Advisor), Ray Wennig (UCD Staff Research Associate), California Rice Experiment Station staff, producers.

Grant support:California Rice Research Board ($109,394 - 2004, $111,685 - 2005)

Background, rationale and objectives: This UCCE statewide uniform variety-testing program is conducted throughout the California rice producing regions and is an ongoing research project initiated over 30 years ago. Over 90% of the rice acreage in California is planted to public varieties. The breeding staff at the California Rice Experiment Station in Biggs, CA, develops these varieties. The main purpose of the UCCE trials is to evaluate the adaptability of public varieties and advanced lines to different climatic zones and soil types. The objective is to develop reliable data on varietal performance under commercial production practices that allow producers and processors to make management decisions on the selection of appropriate varieties for different locations and planting times.

Research methods: One uniform advanced breeding line trial and one preliminary breeding line trial were conducted at each of eight locations throughout the major rice producing areas of California. The varieties for each trial are grouped as very early maturing, early maturing or intermediate/late maturing varieties and tests are established in commercial fields. The replicated trials typically consist of 30–50 entries. Cooperating farm advisors are responsible for planting the plots, taking notes on varietal performance and arranging harvest with a small-plot combine. Cooperating producers handle all other cultural practices as they normally do.

Extension methods: Information collected from these trials was disseminated through the publication of the Annual Report on Comprehensive Rice Research submitted to the California Rice Research Board. In addition, a summarized version of this report is distributed to producers and other industry representatives by the California Rice Research Board. Agronomy Fact Sheets are produced for newly released varieties to inform growers of the variety characteristics and suggested management guidelines. (Cross-reference non-peer-reviewed 17, 18, 19, 25 and 26; abstract 7; educational presentation 1/13/05).

My role: I was responsible for three of eight statewide trial locations (Colusa, Glenn and YoloCounties). My responsibilities included coordinating with cooperating producers to secure space in commercial production fields, scheduling and carrying out trial set-up and planting, coordinating with producers on field operations, evaluating trials throughout the season, and scheduling harvest. Along with other UCCE staff I contribute to the writing and editing of the Agronomy Fact Sheets, proposal and comprehensive reports submitted to the California Rice Research Board each year.

Results: The identification of appropriate rice varieties for cultivation in specific geographic locations, release of variety M-207 for commercial production, identification of special management guidelines for varieties, funds to maintain our small-plot combine that is used in other rice field experiments, and a strong working relationship with the California Rice Experiment Station personnel. M-207 is the first commercially released California rice variety with major gene resistance to the rice blast pathogen.

Impacts: Development ofnew rice varieties for California has allowed producers to remain competitive in a global market. Increased yields and development of specialty rice varieties have both contributed to grower returns. These new varieties are the result of many years of collaboration between UCCE and the California Rice Experiment Station. Variety trial results and management guidelines are widely used by producers to choose appropriate rice varieties for their specific situations. The release of M-207 will allow growers in rice blast prone areas an alternative to fungicide applications for disease management.

1.2 Soil Fertility and Fertilizer Use in Rice (2004-2005)

Collaborators:Chris van Kessel, Bruce Linquist, Kaden Koffler, Chris Hartley (all members of UCD Dept. of Plant Sciences), William Horwath (UCD Dept. of Land, Air and Water Resources), Cass Mutters (Butte Farm Advisor), producers.

Grant support:California Rice Research Board support ($44,403 - 2004, $59,592 - 2005)

Background, rationale and objectives:In the past, rice nutrient management decisions were based upon a system in which the rice straw was burned at the end of the growing season. California legislative action in 1991 mandated that the number of acres of rice straw burned be phased down over a 10 year period.Today, rice growers may only burn a maximum of 25 percent of their fields and only when significant levels of disease are present. Overall, the average amount of rice straw currently burned in any year is less than 15 percent. It has become apparent that nitrogen fertilization must be adjusted to account for changing soil nitrogen status to obtain optimal returns in a system that now commonly incorporates rice straw into the soil.The focus of the project was to evaluate the impact of grower management practices on nutrient cycling and to develop improved fertility management guidelines for rice growers.

Research methods:There were basically two components to this project. One involved changes in nitrogen fertility management following reductions in straw burning (component 1)and the other involved determining the efficiency of starter nitrogen fertilizer uptake under different straw management practices (component 2). 2005 was the third and final year of the first component and involved field trials in 71 fields in 2004 and 44 fields in 2005. Within each field, test plots were established to determine the impact of 25 lb N/ac increases and reductions in pre-plant aqua-ammonia fertilizer application rates on mid-season fertility indicators and yield under different straw management practices. 2005 was the first year of the second component. On-farm starter nitrogen trials were started in 2005 at five sites (10 fields)that had side by side straw burned and incorporated fields or checks, allowing usto compare the interaction between starter N uptake and efficiency and straw management.

Extension methods:Information collected from these trials was disseminated through the publication of the Annual Report on Comprehensive Rice Research submitted to the California Rice Research Board. In addition, a summarized version of this report is distributed to producers and other industry representatives by the California Rice Research Board. Findings from these trials have been presented by one of the team members at each of our UCCE Annual Rice Grower Meetingsand Rice Production for a combined total attendance of over 800 for 2004-2005. (Cross-reference non-peer-reviewed 21 and 27; abstract 9).

My role:My role is to help coordinate on-farm research trials and facilitate education and outreach methods.

Results:Results of nitrogen fertility trials have shown that under a system of continuous straw incorporation, initial fertilizer rates that are typically used when burning rice straw may be reduced by up to 25 lb N/ac with minimal effects on yield. Data are still being analyzed from the 2005 starter fertilizer experiment but it appears that starter nitrogen uptake and efficiency is higher in fields with straw incorporation than in burned fields.

Impacts:As straw management methods have changed over the years, the information from these studies has prompted growers to think more about their nitrogen management.Many growers have reduced pre-plant nitrogen applications and have begun to rely more on mid-season monitoring to determine if there is a need for topdressing. These practices allow growers to optimize yields/returns and reduce complications such as lodging and increased disease pressure due to excessive nitrogen.

2.1Integrated Strategies to Manage Resistant Weeds and Reduce Herbicide Use in California Rice(2004-2005)

Collaborators: Albert Fischer (UCD Dept. of Plant Sciences),Jim Hill (UCD Dept. of Plant Sciences), Marie Jasieniuk (UCD Dept. of Plant Sciences), Cass Mutters (Butte Farm Advisor), Mick Canevari (San Joaquin Farm Advisor), Ron Tjerdeema (UCD Dept. of Environmental Toxicology), Tom Tai (USDA/UCD Dept. of Plant Sciences), Jim Eckert (UCD Dept. of Plant Sciences),California Rice Experiment Station staff, producers.

Grant support:California Rice Research Board support ($99,290 - 2004, $100,241 - 2005), UCIPM Competitive Grants Program ($26,186 - 2004, $12,500 -2005), and UC ANR Core Issue Grant ($34,881- 2005)

Background, rationale and objectives: Widespread weed resistance to herbicides is challenging the sustainability of California rice production. Limited alternatives for rotation to other crops require that “within-rice-rotations” be developed to break weed cycles and limit weed recruitment. The vast majority of rice in California is direct water seeded. This project will develop alternative stand establishment methods to allow rice farmers to reduce the number of herbicide applications and the costs for weed control.In addition, we are working to map the incidence and spatial distribution of herbicide resistant watergrass species to determine which factors are associated with the spread of resistance.

Research methods:A long-term experiment was successfully established in 2004 at the Rice Experiment Station in Biggs, CA to examine the differences between weed populations under dry and water seeded systemsutilizing different tillage regimes. In conjunction with the weed studies we are also evaluating cultural practices and fertility programs to optimize production under each of the systems. For incidence and spatial distribution studies of herbicide resistant watergrass populations, collections of suspected biotypes have been made and resistance screening is being conducted. Distribution maps will be created from this data and historical cultural practice records will be assembled for these locations to help determine if the spread of resistance is due to seed dispersal or independent mutation.

Extension methods:Three field meetings were held for stakeholders at the trial location. In addition, there was a Resistant Watergrass Herbicide Trial Field Day in GlennCounty (8/30/04) and a half day UCCE Rice Herbicide Resistance and Management Meeting (4/5/05). Results were published in the Annual Report on Comprehensive Rice Research submitted to the California Rice Research Board.(Cross-reference non-peer-reviewed 15, 23 and 24; abstracts 4, 5, 10 and 11).

My role: Coordinateeducational activities, facilitate collection of cultural data from herbicide resistant locations, and participate in cultural decisions related to operation of the systems project.

Results: Preliminary results clearly show rotation of these cropping systems has the possibility of providing producers with another option for weed management by shifting species populations. Water-seeding rice (anaerobic environment) greatly reduces recruitment of barnyardgrass and sprangletop compared to drill-seeding. Conversely drill-seeding (aerobic environment) reduces recruitment of watergrass, broadleaf and sedge species. Mapping and distribution of herbicide resistant watergrass populations is proceeding well.

Impacts:The immediate impact of this project is that farmers are starting to consider these system options in dealing with herbicide resistant watergrass populations. There has been strong attendance at our field meetings. With widespread weed resistance, some of the more progressive California rice growers are experimenting with alternative stand establishment systems.This project will allow us to develop recommended long-term management practices for herbicide resistant weed management.

2.2 Occurrence and Management of Red Rice in California (2004 - 2005)

Collaborators: Jim Hill (UCD Dept. of Plant Sciences), Albert Fischer (UCD Dept. of Plant Sciences), Cass Mutters (Butte Farm Advisor), Kent McKenzie (California Rice Experiment Station Director), Bob Stewart (California Crop Improvement), Tom Tai (USDA/UCD Dept. of Plant Sciences), California Rice Commission, County Agricultural Commissioners, producers.

Grant support: None

Background, rationale and objectives: Red rice was widespread in California prior to establishing a certified seed program for rice more than 40 years ago. Since that time there have been sporadic reports of red rice. Large patches of this troublesome weed were identified in a GlennCounty field in late 2003. Red rice poses a serious risk to the California rice industry and has the potential to impact rice yield and quality if this weed is allowed to spread and establish populations throughout the state. After no positive identifications of red rice in 2004, this weed was identified in four fields in Glenn and ColusaCounties in 2005. The objectives of this project were to survey for red rice populations and determine the distribution, develop a management plan for red rice, and educate California rice growers and PCAs about identification and management of red rice.

Research methods:A management plan was developed for the affected grower by doing some background research and consulting with colleagues in the Southern U.S. Field surveys were conducted in the immediate vicinity of the original infested field in 2004 and educational presentations were given to enlist the help of growers and PCAs in identifying new occurrences of red rice. Once new fields were identified, neighboring fields were scouted closely.

Extension methods: Much of the work so far has been in extending information about red rice in an effort to familiarize producers and pest control advisors with the identifying characteristics and biology of this weed. I have encouraged them to be on the look out for red rice and to notify their local Agricultural Commissioner or myself if they suspect this weed in their fields. I have written one newsletter article and have given several presentations to educate pest control advisors and producers about the risk this weed poses to the rice industry and the characteristics used to identify this pest. (Cross-reference newsletter article 12; Appendix 1 presentations 1/27-29/04, 2/27/04, 3/11/04, 11/09/05).

My role: My role in this project has been in taking the lead for UC to coordinate other scientists, producers, and the Agricultural Commissioners’ staffs in a proactive approach to this problem.

Results: Management guidelines developed for the original affected field were quite successful. The grower left the field fallow with flushing and two Round-up applications in 2004 but was adamant about planting rice in 2005. Management practices for 2005 followed our recommended guidelines but red rice again returned but at about 1% of the population size in 2003. We approached this field aggressively and mechanically removed all visible red rice plants from the field. Three other fields were also confirmed with red rice in 2005 and I assisted in facilitating an aggressive approach to removing the plants from these fields.

Impacts:I feel I have done an impressive job in raising awareness to the issue and educating the rice industry. The issue of red rice is gaining more attention with the discovery of three more infested fields in 2005 and I have been able to solicit the help of CDFA personnel for a 2006 survey. In addition, I will be submitting proposals to several funding agencies to determine the distribution of red rice in California fields and develop an aggressive management plan to prevent the spread and establishment of this weed.

2.3Impact and Management of Bakanae Disease (2004-2005)

Collaborators: Cass Mutters (Butte Farm Advisor), Jeff Oster (California Rice Experiment Station plant pathologist), Bob Webster (UCD Plant Pathology Department), producers.

Grant support: Various donors support of $5,000

Background, rationale and objectives: The purpose of this project was to quantify yield loss and develop a more practical seed treatment method for bakanae disease in California. This is a continuation project from 2003. This fungal disease is seedborne and was first identified in California in 1999. In 2003, Ultra Clorox received a label amendment for soaking rice seed as a control for bakanae disease. The label specifies a 2-hour seed soak time in a 5% Ultra Clorox solution followed by draining and soaking in water for at least 22 hours. Some seed handlers soaked seed in reduced rates of Ultra Clorox (2%) for 24 hours in an effort to save labor and material costs. The efficacy and safety of this practice was not known because there was not enough experimental data available. Experiments were designed to determine if reduced Ultra Clorox concentrations and longer soak times were safe and effective.

Research methods: Three identical small plot trials were conducted in 2004 and two identical small plot seed treatment trials were conducted in 2005 to evaluate different seed treatments (materials/rates/treatment times) for bakanae management. Plots were also included in the trials to evaluate the potential yield losses due to bakanae disease. These plots were planted with seed that was artificially inoculated with different concentrations of spores of the pathogen to determine yield losses at different disease infestation levels. Trials were established in commercial fields. Plots were seeded by hand and data were collected on stand establishment, seedling vigor, and disease incidence throughout the season. Plots were harvested with a small-plot combine to determine yield. Cooperating producers handled all other cultural practices as they normally do.