Steven L. Dennis, Chairman
The California rice industry has evolved into one
of the most productive and efficient commodities in the state. We owe most
of this progress to the scientific studies we continue to fund through the
Rice Research Board. As the diversity of the studies summarized in this 22nd
annual report will attest, however, that dedication extends also to
maintaining the quality of our environment.
The value of the rice breeding program can't be understated. The overwhelming majority of California rice acreage is planted with the 25 improved public varieties developed by the Rice Experiment Station. Average statewide yields stand now at nearly 8,000 pounds per acre-that's a 69 percent increase over 22 years ago. The overall increased production is estimated at 39 million hundred pounds worth $391 million. A comparison of gross returns attributed to improved rice varieties and total expenditures for the rice breeding program shows a current return on investment of approximately $38 for each dollar invested.
Highlights from last year's work include the release of a new, higher yielding long grain, 'L-203'; the introduction of more than 90 new foreign germplasm lines; Foundation seed increase for an early maturing medium grain; and a strong effort to improve premium quality short grains through a number of approaches. Other developments are also reported.
RES plant breeders and University of California farm advisors continue to monitor the progress of promising new lines through statewide variety trials. In last year's trials, some experimental and commercial cultivars produced more than 11,000 pounds per acre. The new long grain, 'L-203,' also performed admirably at over 10,000 lbs/acre.
Research into weed control showed that an experimental post-emergence foliar applied herbicide looks promising as a new tool for watergrass control. Ongoing studies of Londax® indicate that it may be used at lower rates and with later timing. Additionally, researchers report on combinations of Londax® with other herbicides.
In contrast to 1989, growers last year weren't faced with extensive Rice Water Weevil infestations. Nonetheless, researchers report encouraging results from their efforts to develop new tools to control this pest. An experimental pyrethroid insecticide showed control of adult weevils comparable to carbofuran. The nematode, Steinernema carpocapsae, continues to show good control of RWW larvae. Finally, cultural controls showing promise include late flooding, early drainage and weed management.
Progress in efforts to control rice diseases, especially stem rot, are also reported. Most significantly, researchers isolated one fungus that slightly increased decomposition of rice straw, and fungi capable of parasitizing stem rot were isolated for the first time. Results of a comparison of how different commercial cultivars react to stem rot is also contained in this report.
Soon rice growers will be able to more efficiently customize management strategies with CALEX for rice, an "expert" computer system similar to a program in use by San Joaquin Valley cotton growers. It is currently under evaluation by UC rice advisors.
Another project has developed a mathematical model that quantifies the factors that control growth rates of different rice cultivars. These scientists also measured differences in cold tolerance for potential use in genetic screening.
The inheritability of plant characteristics that affect head rice yield are also reported. Panicle and kernel characteristics were found to be highly heritable, while milling quality characteristics were not..
Three projects in the general area of product development are also reported. The first study refuted conventional wisdom that rice is inferior to corn as a brewer's adjunct. Indeed, the opposite was determined to be the case in many respects.
Meanwhile, the USDA Agricultural Research Service reports that studies of both human and animal subjects continue to show rice bran has a positive impact on serum cholesterol. They are also studying new methods of processing rice flour and new methods of predicting rice flour characteristics.
Finally, researchers began exploring ways to develop a fat-protected rice bran product for the dairy industry to enhance the nutritional characteristics of milk intended for human consumption. Initial efforts have. not been successful.
A significant amount of your research dollar is also spent to maintain environmental quality. One project continues to evaluate the environmental fate of the chemical tools we need to remain competitive. This last year it determined that diflubenzuron (Dimilin®) can be classed as a non-persistent pesticide and that Londax® breaks down within two days in water but persists longer in sediment. These scientists are also developing new research methods to analyze persistence and fish toxicity
A new research project is attempting to find alternative methods of rice straw disposal while incorporating the use of green manure. In the first year of this multi-year study, observations from both the field and the greenhouse gave no indication that a green manure crop will accelerate straw decomposition. However, purple vetch used as green manure showed greater nitrogen efficiency than preplant fertilizer.
The rice industry has also responded to air quality concerns by funding two additional studies. The first is attempting to analyze the components of rice smoke both in the field and in a wind tunnel that simulates field conditions. The second study is analyzing the respiratory health of rice growers and their workers. Findings from the survey are due in fall 1991, with a project report expected in December 1991.
Meanwhile data from the agricultural burning program shows that despite persistent atmospheric inversions last fall, air quality remained good during the season. The success of the program over the last 10 years is graphically illustrated in this report. Suggested refinements in the program are also included.
In summary we can be proud of past accomplishments, but we must maintain our commitment to the research that will ensure our economic prosperity and environmental quality.