Chairman's Report, 2019


Drew Rudd, Rice Research Board Chairman

Welcome to the 51st annual report to the California Rice Growers. In the following pages, we report on grower funded research from 2019 that is essential to the California rice industry. This report details progress on rice breeding, genetic improvement, variety trials, weed and disease management, fertilizer guidelines and remote sensing, invertebrate pest control and insect monitoring, water use efficiency, environmental concerns, and studies examining rice byproduct utilization.

California’s public rice breeding program is conducted and managed by scientists at the Rice Experiment Station (RES). The program has made 51,439 crosses and released 51 improved public rice varieties in 11 different market classes since its inception in 1969. Foundation seed headrows were grown for breeder seed of A-202, Calaroma-201, M-210, M-104, and Calamylow-201 in 2019. Headrows of experimental line 10Y2043, released as S-202 in early 2019, as well as headrows of 12Y2175 (M-211) and 14Y1006 (L-208), approved for foundation seed increase, were also grown. Read about the intensive work involved for new variety development in the Rice Breeding Program section.

Testing of promising experimental lines takes place at farm locations and at the RES. Top-yielding advanced lines are reported, along with yields of standard varieties. Testing advanced and preliminary lines under a variety of conditions is a critical aspect of new variety development. Results of this testing are described in the Rice Variety Trials section.

Geneticists continued research to select genes associated with reduced uptake of arsenic in rice. Progress has been made with experimental lines that could prove helpful in the development of rice varieties with reduced grain arsenic. Two experimental lines also demonstrated high stem rot tolerance. This work is reported in Genetics for Rice Improvement.

A new project examined ways to treat rice seeds to improve early plant growth. This could lead to multiple advantages in the rice crop. Read about this promising research in Treatment of Rice Seeds for Early Growth.

Fertilizer research in 2019 continued a focus on remote sensing of nitrogen status. Two methods are proving to be useful tools to determine when a top-dressed nitrogen application is needed. Other work on this project examined the potential for early season nitrogen loss through denitrification and as nitrous oxide. Experiments showed that 20 to 25 pounds/acre of fertilizer nitrogen can be lost through early season drainage events. Work also continued on fine-tuning the practice of alternating wet and dry conditions known as AWD. Read about this work in Improving Fertilizer Guidelines for California’s Changing Rice Climate.

Weed management research focuses on new and existing herbicides, alternative crop establishment methods, and herbicide resistance strategies. Several herbicide combinations delivered near-perfect weed control with great crop safety. Thirteen separate studies in 2019 evaluated different formulations and new active ingredients in continuously flooded rice systems. Clomazone has been used to control bearded sprangletop since 2004. However, its continuous use in some fields has resulted in resistance by certain populations of this weed. A survey helped pinpoint areas where this is a problem. This work is reported in Weed Management in Rice.

Scientists have been working with the industry since 2016 on weedy rice. A total of seven biotypes of weedy rice have now been identified. Soil sampling from rice fields shows that growers who have taken steps to reduce infestations tended to have lower seed counts. A competitiveness study has shown that all weedy biotypes have a significant effect on M-206, including aboveground biomass, panicle weight and number, and yield per plant. This research is reported in Weedy Rice Control. A related study is reported in Evaluating the Potential for Aerial Imagery to Detect Weedy Rice.

Within the past six years, a number of new weed species have been identified. The range of some of these species is unknown. Since the last weed survey was conducted in the 1980s, a project was initiated to provide the industry with more current information. Survey results are pending. Learn more in Emerging Weed Issues in Rice.

Rice diseases of concern to the California rice industry include aggregate sheath spot, stem rot, and kernel smut. In 2019 eight fungicide trials were conducted—five in Butte County, the others in Colusa, Glenn, and Sutter counties. In general, results indicate that reduction in stem rot, aggregate sheath spot or blast incidence and severity can be achieved with applications at midboot stage. Also a rice disease survey took place to authorize a burning program for 2020 to 2024. This work is reported in Rice Disease Research and Management.

Although rice water weevil (RWW) has been in California for more than 60 years, populations have been declining. Most growers and pest control advisers no longer consider RWW a key pest. Control studies have also become more challenging as a result. Armyworms, on the other hand, have become an increasing concern. Use of pheromone traps to improve detection has expanded the last two years. More frequent trap monitoring and use of other types of traps could also better time scouting and treatment needs. More testing also is needed to improve insecticide efficacy. A simulated defoliation study took place at the Rice Experiment Station, demonstrating impacts to panicle emergence and heading at different levels of damage. This, and related research, is reported in Protection of Rice from Invertebrate Pests.

Research on how rice pesticides degrade in the environment focused exclusively in 2019 on the the insecticide Coragen® (chlorantraniliprole), registered in California as a preflood treatment to control rice water weevil. Studies concentrated on simulated California rice field conditions and produced results suggesting that it may accumulate in soil because it degrades slowly. Read about this research in Environmental Fate of Rice Pesticides.

In work examining arsenic uptake during cultivation, researchers analyzed some of the minerals present in rice roots. Minerals that may bind easily to arsenic were found in the most intense AWD treatments. They also evaluated the potential for using magnetic biochar to remove metals from soil. Read about this research in the section Arsenic Speciation in Rice and the Environment.

Another project completed its previous work on water use in California rice systems, with three areas of accomplishment—a crop development model, quantifying salinity, and a better understanding of seepage and percolation rates. Attention is now focused on how land use changes in the Sacramento Valley are linked to water and what that could mean for the future of the rice industry. Data are presented on shifts in rice acreage and other crops. Read more in Identifying Opportunities for Improving Water Use Efficiency.

Engineers made improvements to a real-time insect monitoring and detection system for use in rice storage facilities. Research in 2019 focused on improved handling, convenience, effectiveness, and accuracy, as well as reducing energy use. Testing in the laboratory and at a rice storage facility were very positive, but further refinements are needed before scaling up to commercial application. Read about this research project in Insect Monitoring and Early Detection System for Rice Storage.

An ongoing project studying the conversion of rice straw components into nanomaterials and advanced functional products continues to produce impressive results. A diverse array of nanocelluloses have been fabricated, and a number of patents have been filed to facilitate technology transfer. This work is reported in Novel Nanomaterials and Performance Industrial Products.

A project at Chico State is studying potential applications for rice straw and hulls—one for an automotive interior part and the other for plastic bags. Addition of rice straw and hulls significantly improved properties of both the auto part and plastic bags. Read about this research in Potential New Uses for Rice Straw and Hulls.

There is a great deal of interest in the potential for using rice-based ashes in concrete to fill a growing need in the construction industry and to help meet carbon emission reduction requirements. Research examined different leaching methods to remove unwanted alkali metals from rice-based waste. To determine the benefits and constraints affecting economic feasibility, an industry survey revealed some of the concerns of bioenergy facilities, hullers, straw balers and concrete suppliers. Read more in Feasibility Assessment for Use of Rice Straw Ash in Concrete.

That’s a quick summary of grower funded research from 2019. With 50 years of progress behind us, it’s exciting to contemplate what the future holds and what the rice industry will look like at 100. Your support of the work the Rice Research Board invests in every year is crucial. As the world grapples with the realities of a pandemic, there’s no doubt about the essential role that California agriculture plays. The rice industry is an indispensable part of our food security, and we take pride in our work. Wishing you all the best for another safe and productive year in rice country.

—Andrew Rudd, chairman