Rice Variety Trials, 2017

 

Project Leader

Bruce Linquist, UCCE specialist, Dept. of Plant Sciences, UC Davis

Sixteen on-farm rice variety evaluation trials were conducted throughout the rice growing regions of California in 2017 by UC Cooperative Extension scientists in cooperation with plant breeders at the Rice Experiment Station (RES). Standard varieties were compared with preliminary and advanced lines in these tests to measure performance across a range of environments, farmer practices, and disease levels.

Six similar tests were conducted at the RES in Biggs—two from each maturity group. Average yields across varieties and locations in the advanced-line tests ranged from 8,960 pounds/acre in the very early tests to 9,180 pounds/acre in the early tests. In the intermediate/late tests, the advanced lines average yield was 8,980 pounds/acre.

The 2017 season was unusual because a very wet spring resulted in late planting and also warmer than average temperatures. These factors, among others (i.e. higher than normal pests and disease incidence and increased lodging), resulted in lower yields than have been reported in the past few years.

Several advanced lines in 2017 produced high yields and demonstrated advances toward other important breeding goals aside from yield, such as disease resistance, grain quality, and specialty types. Testing advanced and preliminary lines under a variety of conditions remains a critical aspect of releasing varieties adapted to changing cultural practices, markets, and pests.

Rice variety evaluations

Eight uniform, advanced breeding line trials and eight preliminary breeding line trials were conducted throughout the major rice producing areas of California. The RES rice breeders conducted six additional tests—two from each of the three maturity groups. Many of the experimental lines have been tested and screened in previous years and were advanced for further testing. The RES provided the seed for public varieties and experimental cultivars. No proprietary lines were tested. The following provides agronomic performance summaries for these tests.

Very early maturity

Eight advanced breeding lines and nine commercial varieties were compared in four very early advanced tests. The preliminary tests evaluated five commercial varieties and 29 preliminary lines evaluated in separate tests at each location. Commercial varieties at each location included S-102, CA-201, CH-202, CM-101, CM-203, M-104, M-105, M-205, M-206, M-208, M-209, L-206, and L-207.

Grain yields in the advanced tests averaged 8,960 pounds/acres overall, 9,930 pounds/acre at RES, 9,320 pounds/acre at Sutter, 8,930 pounds/acre at Yolo, and 7,650 pounds/acre at south Yolo. The three highest yielding entries on average were long grain L-207 (9,880 pounds/acre), long grain line 14Y1006 (9,680 pounds/acre), and advanced short grain line 10Y2043 (9,640 pounds/acre). Top yielding commercial varieties included L-207,

CM-203, M-105, and M-206. Averaged across three locations, yields for lines in the preliminary tests ranged from 9,340 pounds/acre to 6,710 pounds/acre.

Average grain moisture at harvest increased 0.2%, lodging decreased 12%, while average number of days to 50% heading decreased from 88 to 82 days compared to 2016. Seedling vigor and plant height were essentially the same as in 2016. Field preparation and planting were delayed because of the wet spring. Harvest was completed within the normal time frame. Yields were down 13% from 2016.

Comparing commercial standard entries over a five-year period and across locations, M-105, M-206, and M-104 were the highest yielding varieties at 9,263 pounds/acre, 9,067 pounds/acre, and 8,907 pounds/acre, respectively.

Early maturity

Nine advanced breeding lines and eight commercial varieties were compared in four early advanced tests. Preliminary tests included six commercial varieties and 32 preliminary lines evaluated in separate tests at each location. Commercial varieties at each location included S-102, CH-201, CH-202, CM-101, CM-203, M-104, M-105, M-205, M-206, M-208, M-209, A-202, L-206, and L-207.

Yields in the advanced lines averaged 9,180 pounds/acre overall, 10,660 pounds/acre at RES, 9,240 pounds/acre at Butte, 8,230 pounds/acre at Colusa, and 8,580 pounds/acre at Yuba. Advanced long grain line 14Y1006 was the highest yielding entry (10,330 pounds/acre) averaged over four locations in 2017. Advanced short grain line 10Y2043, long grain L-207, and medium grain premium quality 12Y2175 yielded second, third, and fourth, respectively. Top yielding commercial varieties included M-209, L-206, M-206, M-105 and CH-202.

Average number of days to 50% heading was 80. The commercial standard M-206 averaged 77 days over four locations. The average yield of M-105 decreased 12.6% compared to 2016. In the preliminary tests, CM-203 was the highest yielding commercial variety, with two experimental lines yielding higher.

Over a five-year period and across locations, L-207 was the highest yielding commercial variety at 10,200 pounds/acre, followed by M-209 at 9,468 pounds/acre, and L-206 at 9,415 pounds/acre.

Intermediate/late maturity

Four advanced experimental lines and eight commercial varieties were compared in three intermediate/late tests. Preliminary tests included four commercial varieties and 18 preliminary lines evaluated in separate tests at each location. Commercial varieties at each location included S-102, M-104, M-105, M-205, M-206, M-208, M-209, M-401, M-402, A-202, L-206, and L-207.

Yields in the advanced lines averaged 8,980 pounds/acre overall, 10,450 pounds/acre at RES, 8,940 pounds/acre at Butte, and and 7,550 pounds/acre at Glenn. The 2017 advanced over-location yield decreased 210 pounds/acre (2.3%) compared to the 2016 season average. The average yields at the Rice Experiment Station decreased 460 pounds/acre, increased 200 pounds/acre at Butte, and decreased 1,310 pounds/acre at Glenn. In the advanced tests, L-207 was the highest yielding commercial variety (9,600 pounds/acre). L-206 and M-209 were the next highest yielding commercial varieties. The long grain entry 14Y1006 was the highest yielding advanced entry across locations at 10,050 pounds/acre.

Average number of days to 50% heading decreased eight days compared to 2016. M-401 and M-402 were the latest among the commercial varieties at 111 and 108 days, respectively. Over a five-year period and across locations, L-206 is the highest yielding commercial variety in this group at 9,407 pounds/acre, followed closely by M-209 at 9,250 pounds/acre.

Other activities

This project was involved in the planting, sampling, and harvesting of more than 12 trial sites throughout the rice growing areas. Educational activities such as winter rice grower meetings, the annual field day at the Rice Experiment Station, and promoting work through fact sheets, publications, and the UC Cooperative Extension rice website are also important parts of this project.