Tables 1 and 2, respectively, show the results of the 2015 San Joaquin County rice variety trial and a 5-year yield summary of very early maturing commercial varieties. The statewide trials are a cooperative effort of the California Cooperative Rice Research Foundation, Inc., the United States Department of Agriculture, and the University of California. The trials compare advanced breeding lines with commercial varieties. The San Joaquin County test site is located in the Delta. It is a test site for very early maturing varieties because San Joaquin County is cooler than other rice growing regions of the state. The varieties were drill-seeded on April 29^th at a rate of 140 lbs/acre and harvested on October 13^th.

When interpreting the results, consider the following. The mean represents the average of all varieties. The CV, or coefficient of variation, is a measure of variability of the data in relation to the mean. The LSD (.05), or least significant difference at 95%, is used to compare means of different varieties. When the difference between two varieties exceeds the LSD value, we are 95% certain that the two varieties performed differently; the results are not due to random chance. For example, the LSD of the grain yield at 14 percent moisture is 640. This means that if the yields of two varieties differ by at least 640 lbs/acre, then we can conclude that the two varieties yielded differently. In this case, the top six varieties in Table 1 had statistically similar yields. In Table 2, yield means are averaged across all locations and years and compared to M-104, a standard very early variety. Over the five years, and across the four very early variety locations, M-206 – a common variety in this area – yielded 2.2 percent higher than M-104.