|Variety Adaptation and
Project Leader and Principal UC Investigators
James E. Hill, Cooperative Extension specialist and associate in the Agricultural Experiment Station, UC Davis
The varietal adaptation and cultural practices project is conducted by Cooperative Extension and is responsible for testing new breeding materials developed by the Rice Experiment Station and by privately funded rice breeders. Yield and other agronomic characteristics such as time of heading, lodging, and seedling vigor are determined in grower fields under different environmental conditions. Cultural practices such as fertilizer management and seed coating are also studied. The project also provides professional assistance to other field research projects and an equipment pool for planting, fertilizing and harvesting field experiments.
Statewide Uniform Rice Variety Trials
Thirteen variety evaluation trials were conducted in ten locations from Butte to Stanislaus counties. A total of 82 experimental cultivars were tested. Additional public and proprietary varieties were included to serve .as standards and to develop information on their performance.
Very early variety trials were conducted in three locations, but only the trials at the Rice Experiment Station and in Sacramento County are reported. Seventeen of 25 varieties yielded over 10,000 pounds per acre when averaged over the two locations Among the commercially available varieties, Calpearl and M9 yielded 10,490 pounds per acre.
Several experimental varieties are in the second, third, or fourth years of off-station testing. The goals are to find an improved variety to replace M-101, a cool region medium grain substitute for M9 or M-201, and a very early pearl. One experimental variety (81-y-124), a medium grain variety for cool regions, is being increased in anticipation of its possible release.
Early variety trials were conducted at five locations, one of which was at the Rice Experiment Station. Not all varieties were included at the station trials. Consequently, some comparisons must be made separately for fiveand four-location experiments. Calpearl was the highest yielding commercial variety for the off-station trials, with an average yield of 9,330 pounds per acre. Over the five locations, excluding Calpearl, the top yielding commercial variety was S-201 which produced 9,310 pounds per acre. California Belle was the lowest yielding variety in the five-location trial of commercial varieties, with an average yield of 7,570 pounds per acre.
A number of experimental varieties produced very high yields, indicating potential for further improvement in new varieties. The variety 81-y-124, also included in the very early variety trial, yielded approximately the same as Calpearl in the four-location average.
One of the goals of the rice variety program has been to develop and test high yielding long grain types with acceptable market quality. One of these selections is being released as L202. It is a semi-dwarf which yields approximately 1,500 pounds per acre better than California Belle.
Intermediate and late variety trials showed that the leading late variety among commercial varieties was M401, which yielded 9,660 pounds per acre compared with 8,660 pounds per acre for M7. Although a number of late experimental cultivars look promising, none has been identified as a candidate for release. The move toward early and very early varieties is widely accepted by the rice industry, so emphasis is being placed on the release of needed varieties in these earlier maturity groups.
Long grain variety trials included California Belle, L-201, and the medium grains M-201 and M-302 as check varieties. Nine experimental long grains in addition to M-201 yielded over 10,000 pounds per acre. The new variety L-202, ranked fourth in the long grain test at 10,550 pounds per acre. It was approximately the same as M-201 and nearly 1,000 and 2,000 pounds per acre over L-201 and California Belle, respectively.
Evaluation of Rice Seed Coating
Replicated trials compared standard soaking with commercially coated seed. The coating contained talc, wood molasses, zinc oxide, and a fungicide. Preliminary results indicate differences among various measurements, but it would be premature to 'draw conclusions without further studies.