Objective

To develop adapted new high yielding varieties that resist blanking, are earlier maturing within each maturity group, have good seedling vigor, are short statured and lodging resistant, have disease and insect resistance, and have superior grain qualities.

The first commercial seed field of the new short-statured pearl S-201 is being inspected prior to harvest in October, 1979. Grower Thomas W. Carlson is in overalls. Plant breeders who developed the variety are (left to right): Drs. Howard L. Carnahan, Carl W. Johnson and S.T. Tseng. Experiment station director Morton D. Morse is far right.

New Varieties In 1979 California rice growers . established a new all-time yield record estimated at 6,450 pounds per acre. This is nearly 640 pounds per acre higher than the 1977 record. Statewide in 1979 the new short-stature varieties occupied an estimated 51 percent of the acreage as follows: M9 - 29 percent, M7 -15 percent and Calrose 76 - 6 percent. Occupying 61 percent of the rice acreage in Butte County in 1979, the new short-statured varieties yielded 1,113 pounds per acre more than the tall varieties. These new varieties undoubtedly played a major role in the attainment of the new yield record, although good weather was also an important factor. The short-stature varieties generally lodged much less than tall varieties, thereby offering an additional benefit to growers. Even so, straw strength of the short-stature varieties needs further improvement, and we are working toward this goal with some encouraging results.

The third benefit of the short-stature varieties is the reduced amount of straw produced per acre. This, in turn, results in less smoke per acre from the necessary burning of straw and stubble.

Registered Seed

Approximately 200 acres of registered seed of the new very early maturing short-stature, smooth, medium-grain M-101 was grown by seed growers in 1979. Foundation seed was also produced. M-101 is about four days earlier than Earlirose.

With excellent seedling vigor and good cold tolerance, it should become a popular variety in the colder areas of the state where M-9 should not be grown. It should also provide flexibility in that it can be seeded late or be used for re-seeding in warmer areas. It should not be seeded early in the warmer areas because ripening during high temperatures may result in a low head rice percentage. Harvesting at 22 percent moisture or higher might minimize this problem.

Registered seed from approximately 100 acres of the new early-maturing, smooth, intermediate-height, long-grain L-201 was produced in 1979. Foundation seed was also produced. In 1979 statewide trials it averaged slightly higher yields than M-9 (8,344 pounds per acre vs. 8,163 pounds per acre). Part of this L-201 seed will be milled for further market acceptability testing.

Rice Experiment Station scientist Dr. S.T. Tseng directs the plant breeding program to develop better long-grain varieties for California production.

L-201 is best suited for the warmer areas of the state. It is susceptible to high rates of Ordram, but economic injury has not been observed at three pounds active ingredient of Ordram per acre. After heading, the seed of L-201 matures 7 to 10 days faster than the short- and medium-grain varieties. Additionally, it threshes easily at a 22-inch cylinder speed of around 500 rpm. Since it is difficult to get good head rice in long-grain varieties, it is important to harvest L-201 when it is between 23 and 25 percent moisture.

Registered seed from about 200 acres of an early-maturing, smooth, tall, sweet rice otherwise quite similar to S6 was grown in 1979. This is considered an interim variety that will be replaced by a short-stature variety, so no foundation seed was produced.

Registered seed from about 300 acres of a new intermediate-maturity (M5 maturity), smooth, short-stature, medium-grain variety was produced. Certification is pending. Based upon its performance in 1978 and 1979, it has been named M-301 and released. It has averaged around 800 pounds per acre higher yield than M5 and has lodged much less. It has good seedling vigor and resistance to blanking and will replace M5 very rapidly.

USDA researcher Dr. J. Neil Rutger (left) and UCD researcher Dr. M.L. Peterson examine new short-statured genetic lines at the UCD rice research facility which the Rice Research Board helps maintain. These two scientists cooperate on basic genetic and physiological studies essential for the general rice research program.

Foundation Seed

Fifty-eight acres of foundation seed of a new short-stature early-maturing (S6 maturity), smooth, short-grain variety was produced in 1979. It produced 8,200 pounds per acre of dry paddy. It has been named S-201 and will be released to seed growers. The amount of clean-seed available should permit the seeding of approximately 3,000 acres in 1980 for registered seed production. This should provide enough seed for 100,000 acres in 1981.

S-201 will replace S6. During the last two years in statewide tests, it has yielded over 1,100 pounds per acre more than S6. In 1978 it yielded the same as M9 but averaged 470 pounds per acre more than M9 in 1979. It has good seedling vigor and a little more resistance to blanking than S6.

Visitors to the Rice Experiment Station variety breeding plots are being shown potential long-grain varieties. From left to right: Milton D. Miller (Rice Research Board consultant); Rice Experiment Station plant breeders, Drs. Howard L. Carnahan, S.T. Tseng and C.W. Johnson; Mitzi Ayala, rice grower and writer; Dr. Ted H. Johnston of the USDA.

A premium-quality, smooth, short-stature, late-maturing, medium-grain experimental has large translucent seeds. It is not as resistant to blanking as M7, nor is the straw as good as M7. However, during the last two years it has yielded as much as M7 and about 1,300 pounds per acre more than the tall commercial variety with which it was compared. Foundation seed will be produced in 1980 in anticipation of releasing it as M-401. It should complement, but not replace, M7.

An early-maturing, short-stature, smooth, experimental sweet rice with short grain gave high yields in 1979 statewide tests. It averaged 8,898 pounds per acre as compared to 6,958 for Calmochi-201, an advantage of more than 1,900 pounds per acre. Foundation seed will be produced in 1980 in anticipation of releasing it in 1981 as a replacement for Calmochi-201 if quality evaluations are acceptable.

 

Table 1. Current public rice varieties in California (Short-stature varieties are in italics.)
Variety	Grain Type	Maturity*	Remarks
Colusa	Short	Early	Released in 1918; grown on 2% of acreage in 1979
S6	Short	Early	Released in 1974; grown on 30% of acreage in 1979
S-201	Short	Early	Released in 1980
M-101	Medium	Very Early	Released in 1979; grown on 0.1% of acreage in 1979
M9	Medium	Early	Released in 1977; grown on 29% of acreage in 1979
M5	Medium	Intermediate	Released in 1975; grown on 7% of acreage in 1979
M-301	Medium	Intermediate	Released in 1980
Calrose	Medium	Late	Released in 1948; grown on 7% of acreage in 1979
M7	Medium	Late	Released in 1977; grown on 15% of acreage in 1979
Calrose 76	Medium	Late	Released in 1976; grown on 6% of acreage in 1979
L-201	Long	Early	Released in 1979; grown on 0.1% of acreage in 1979
Calmochi-201	Sweet	Early	Released in 1979; grown on 0.1% of acreage in 1979
*Very early, <90 days (100 series)      Early, 90-99 days (200 series)      Intermediate, 100-105 days (300 series)      Late, >105 days (400 series)

Promising Materials

A new combine, provided by research contract funds through your Rice Research Board, cleans up experimental plots which had just been hand harvested at the Rice Experiment Station. This new equipment can be quickly modified to harvest yield trials of the most promising, superior experimental lines. The greatly expanded rice seed bin drying and storage facility in the background insures that pure seed arrives on your farm for your use.

An experimental early, short-stature, medium-grain of M9 maturity looks very promising. It ranked first in yield among 77 entries tested at Biggs in 1978 and averaged 1,185 pounds per acre above M9. In 1979 tests at Biggs it averaged 9,738 pounds vs. 8,374 pounds for M9. Its yield in Yolo County was also above M9 but lower than M9 on red soil in Yuba County. An additional outstanding feature of this experimental is that it lodged less than one percent while M9 averaged 45 percent lodging in the same tests. Because the experimental is a likely replacement for M9, one acre of breeder seed will be grown in 1980.

A very early short-grain that headed a week earlier than Earlirose ranked first in yield among 73 very early entries tested at Biggs in 1978. It was compared with M9, M-101, and 25 other rices in statewide trials in 1979. In this warm year, it ranked first and averaged 8,566 pounds per acre, which was 870 to 1,035 pounds per acre more yield than the average of the two named varieties. This very early short-grain will be compared with additional very early pearls in 1980, and a preliminary seed increase of one or more of these may be initiated in 1980.

In 1979 the usual number of crosses were made to bring together desired characteristics. In addition, selection pressures were put upon the many lines selected in previous years to derive the most promising ones for further testing and eventual seed multiplication. The nursery in Hawaii is being continued in order to get two generations each year on selected lines and, thereby, get the new varieties out to growers at the earliest possible date after discovery and proof of superiority.

Foundation seed of M-301, a short-straw replacement for M-5 is being harvested. Rice Experiment Station scientists are responsible for increasing supplies of seed they develop to foundation seed quantities.

Breeding Program

There are many steps between the time when an idea or a seed germinates and when it reaches fruition. Rice growers had a dream, and some 10 years ago they set it in motion by establishing firm financial support for the breeding program. Following that action, the administrators of those funds wisely established priorities and enlisted scientific personnel to get the job done. Scientists from the California Cooperative Rice Research Foundation, University of California, USDA, and California Crop Improvement Association have all contributed. The breeders have streamlined methodologies and used virtually every plant breeding tool available. Cooperative Extension rice specialists and area farm advisors have contributed to varietal development by conducting many variety and cultural tests annually in our rice districts. Results of these tests are used in selecting new varieties for grower use.