UC Cooperative Extension collaborates with the California Rice Experiment Station to evaluate commercial varieties and advanced breeding lines. The San Joaquin County Delta location was one of seven locations in the 2022 statewide trial. The Delta is a test site for very-early maturing varieties because it has cooler growing conditions than other rice growing regions of the state. The trial was drill-seeded on April 19^th at a rate of 150 lb/acre and harvested on October 2^nd. Plot size was 150 ft², and varieties were replicated four times. Table 1 (below) shows variety results at the Delta location (advanced breeding lines omitted). Among the entries, M-206 is the most commonly planted variety in the Delta and across the state. It has good agronomic characteristics and consistent quality across different harvest moistures. Some Delta growers also plant M-105, which is a very-early variety that has yielded well in Delta trials but may be slightly more susceptible to rice blast disease than M-206. Among the newer varieties, M-210 is early maturing, blast resistant, and may be a good option for the Delta. Variety M-211 is not as well adapted to cooler environments, like the Delta, and quality appears to decrease below 18 percent harvest moisture. One of the advanced breeding lines, which is not shown in the table below, but which yielded better the M-206 in the Delta trial, will become CH-203. For a comparison of yield across all seven trial locations, please see the recent edition of the UCCE Sutter-Yuba newsletter. Special thanks go to our grower cooperators for hosting the variety trials. If you have questions about the Delta trial or about Delta rice production, please don't hesitate to reach out to me.

UCCE will host two upcoming meetings for the rice industry:

1. The 2023 Rice Production Workshop will be held March 15-16 at the Lundberg Family Farms facility in Richvale (5311 Midway, Richvale, 95974). This is an in-depth workshop that covers the principles and practices of rice production in California. The workshop is directed toward folks who are new to growing rice or serving the rice industry. The program is available here. Registration is limited, so please sign up early. The registration fee covers the workshop manual and lunches both days. We have applied for DPR, CCA, and CDFA nitrogen management continuing education credits.

2. The Cover Crops in Rice Field Demonstration Day will be held March 27 from 10:00am to 12:00pm. The field day will be held at the corner of Hwy 45 and White Road, Colusa, 95932 (38.969148, -121.866552). At the field day, we will discuss the CDFA Healthy Soils Program, and attendees can walk through the cover crop trial. No registration is required. We have applied for CCA and CDFA nitrogen management continuing education credits. The agenda is attached below.

Table 1. 2022 San Joaquin County rice variety trial results.