Seed Coating

Calcium peroxide is an effective source of oxygen for rice germination and seedling emergence. When coated on seed, planting can be done with a grain drill, or seed can be broadcast and covered with soil before flooding. When oxygen deficiency is corrected and seeds are placed in soil, higher plant survival is obtained, seedling drift is eliminated, seedlings are well-anchored and growth is superior to water sowing. Calcium peroxide seed coating opens the door to bypassing the troublesome seed soaking procedure and offers potential new methods of weed control. In addition to more laboratory work, extensive field tests will be conducted in 1980.

Water Management

Continuous deep water (6 to 10 inches) depressed the grain yields of most new rice varieties at the Rice Experiment Station, Biggs. The deep water treatment decreased the yields. of M9, S-201, M-301 and L-201 but did not affect the yield of M-101. Deep water hastened the maturity of S6, S-201, M9 and L-201 but did not influence maturity of M-301, M5 and M-101. These data indicate that relatively shallow water (2 to 6 inches) is required for maximum productivity of the new short-stature varieties.

Improving Rice Harvest Equipment and Systems

Data developed in 1979 field experiments clearly showed that S6, M101 and L-201 yielded the best head rice appraisal (60 or better) when harvested at 22 percent moisture and with a 22-inch cylinder speed of 810 to 860 rpm. The slower cylinder speed is essential for L-201. Some USDA-UC genetic lines as well as some experimental varieties apparently have genetic characteristics which make it possible to maintain high head rice appraisals when harvested at moisture levels as low as 15 percent. Plant breeders are considering using these lines to improve the harvesting characteristics of new varieties.

To provide growers more timely, accurate information about the pre-harvest and harvest moisture content of their rice, the Dickey-John grain moisture meter, distributed by Deere and Company, has been field tested for two years. Provided a representative, trash free, sample is used, the portable field moisture meter is quite accurate and useful for scheduling harvest operations to maximize grain quality.

Residue Management

Funded by the Solid Waste Management Board, University of California agricultural engineers, plant pathologists and agricultural economists began a three-year rice crop residue management study in Colusa County to determine the economics of various ways of managing rice straw, including complete collection of rice straw for utilization.

The five different treatments in the 89-acre field experiment are:

1. Normal height combine harvest - spread straw - swather-windrower - bale - remove bales from field to stack - disc and/or plow.
2. Combine harvest at ground level - windrow - bale - remove bales from field to stack - disc and/or plow.
3. Normal height combine harvest - windrow - chop - incorporate by disc and/or plow.
4. Normal height combine harvest - spread straw - Haybine-windrow - chop or bale - remove bales from field to stack - disk and/or plow.
5. Normal height combine harvest - spread straw - burn field - disc and/or plow.

Even though weather conditions were reasonably favorable, commercial straw gathering and removal equipment did not work well on big straw windrows or on straw which had been packed against the soil by harvest equipment. Burning to remove the straw was the least costly method.

In a project funded by the Rice Research Board, work began on an economic analysis of residue management alternatives to open field burning of rice straw in the Sacramento Valley Air Basin (SVAB). Specifically, the primary objective is:

• To quantitatively evaluate the expected economic impacts of alternative strategies for rice straw management in the SVAB on rice producers and the rice-related agricultural economy.

Secondary objectives are:

• To qualitatively identify and discuss the probable impacts of decreased emissions on the public health and welfare of residents of the SVAB as alternative residue management strategies are substituted for open-field burning.
• To identify and discuss the economic impacts on the consumers of rice (both foreign and domestic) which could be expected with the implementation of such management alternatives.

Progress was made in planning the research program. No reportable findings are yet available.