Statewide results will be available from the UC Rice webpage (https://rice.ucanr.edu/Reports-Publications/Agronomy_Papers/). Table 1 (below) shows the San Joaquin County results. Among the entries, M-206 is the most commonly planted variety in the Delta, followed by M-105. The average yield across all commercial varieties and advanced lines was 10,129 lb/ac. When interpreting the results, the CV, or coefficient of variation, is a measure of variability in 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.
This trial helps to support the Delta rice industry, which has a different production system from the Sacramento Valley. We plan to continue trialing rice varieties in the Delta again in 2022. Please don't hesitate to reach out if you have questions about Delta rice production, and good luck this season!
Table 1. 2021 San Joaquin County very early rice variety test (advanced lines and varieties).
Results for the 2021 UCCE Delta field corn variety trial are now available. This annual trial takes place on Tyler Island. The trial was planted on April 20th and included sixteen varieties submitted by seed companies and the cooperating grower. We evaluate varieties across three replicate blocks for performance under Delta conditions, including high organic matter soils and pest pressures typical for the region. Of note for 2021, Fusarium ear rot incidence was very low compared to previous years. The trial was harvested on October 1st.
Twelve varieties yielded similarly well, based on statistical analysis, and varieties that yielded lower in the trial had a higher incidence of head smut disease. In addition to yield, there were also statistical differences in days to bloom, head smut, ear height, grain moisture, and bushel weight. A table of results, as well as more information about the experimental design, data collection, and statistical analysis are available from the full report.
The 2020 UCCE Delta field corn variety trial, located on Tyler Island, was planted on April 21st by air planter and consisted of three replicate blocks of seventeen varieties. The seventeen varieties included fourteen varieties submitted by seed companies and three submitted by the grower. All varieties were glyphosate tolerant. Over the course of the season, we evaluated stand count, bloom, disease incidence (Fusarium ear rot, head smut, common smut; Fig. 1), lodging, and yield. The field was harvested on September 25th.
Table 1 presents mean values for the three replicates. The statistical method used to compare the means is called the Tukey's range test. Varieties were considered statistically different if their P value was less than 0.05, or 5 percent. Twelve varieties have a letter “a” following their mean yield, which means that those twelve varieties all yielded similarly in the trial.
In addition to yield, there were also statistical differences among varieties in Fusarium ear rot, head smut, common smut, ear height, grain moisture, and bushelweight. The CV, or coefficient of variation, is the standard deviation divided by the mean, or a measure of variability in relation to the mean. For the diseases, the variability among the three replicates was very high.
For a printable report with more description of the trial, please visit my website. Special thanks go to the cooperating growers, Gary and Steve Mello, and the participating seed companies.
Figure 1. Diseases monitored in the UCCE Delta field corn variety trial: A) Fusarium ear rot, B) head smut, and C) common smut. These three diseases are generally managed by variety selection.
Table 1. 2020 UCCE Delta field corn variety trial results. Results for each variety are expressed as the average across three replications.
* Data were transformed for analysis. Arithmetic means are presented.
‡ Yield adjusted to 15% moisture.
Stand counts were made approximately two weeks after planting. The stand was assessed in the center two rows of each four-row plot, counting the plants along a 10-foot length. Bloom was assessed over the week of July 15th. We monitored disease incidence and plant lodging in late September. Disease incidence, particularly Fusarium ear rot, was lower in 2019 compared to 2018. A sign of Fusarium ear rot is white fungal mycelium around the kernels. The disease is usually introduced to the ears by corn earworm or by thrips that travel down the corn silks at pollination. Incidence may be reduced in varieties with longer or tighter husks that prevent insect infestations. Planting earlier in the season may also reduce incidence, as the crop may reach pollination before insect pests are prevalent. Head smut, a disease that replaces ears with dark brown spores, had low incidence this year. These two diseases are generally managed by variety selection.
The table presents mean values for the three replicates. The statistical method used to compare the means is called the Tukey's range test. Varieties were considered statistically different if their P value was less than 0.05, or 5 percent. What this means is that when differences between varieties exist, we are 95% certain that the two varieties are actually different; the results are not due to random chance. Differences between varieties are indicated by different letters following the mean. For example, a variety that has only the letter “a” after the mean yield value is different from a variety that is followed by only the letter “b”, but it is not different from a variety whose mean value is followed by both letters (“ab”). Similarly, a variety whose mean yield is followed by the letters “ab” is not different from a variety whose mean yield is followed by the letters “bc”. Eight varieties have a letter “a” following their mean yield, which means that those eight varieties all performed similarly in the trial. In other words, based on this research, we cannot attribute numerical differences to varietal differences.
In addition to yield, there were also statistical differences among varieties in days to bloom, Fusarium ear rot, head smut, ear height, grain moisture, and bushelweight. The CV, or coefficient of variation, is the standard deviation divided by the mean, or a measure of variability in relation to the mean. For the diseases, the variability among the three replicates was very high.
For a printable version of this report, please see: https://ucanr.edu/sites/deltacrops/Corn/. Special thanks go to the cooperating growers, Gary and Steve Mello, and the participating seed companies.
The Delta trial was planted on November 15, 2018 and consisted of 38 common wheat varieties and 10 triticale varieties in three replicate blocks. Following a tomato rotation, the trial was planted on 60-inch raised beds, and no nitrogen fertilizer was applied to the field ahead of planting small grains. Neither was irrigation applied during the season, as rainfall amounted to approximately 22.5 inches over the season (Staten Island CIMIS station).
Trial results can be viewed interactively from the Agronomy Research and Information Center Small Grains page. Regional summaries are based on 3 years of trial data across multiple locations. The Delta location is grouped with the Sacramento Valley. These multi-year, multi-environment summaries are what we recommend using for making variety selection decisions because any unusual circumstances in a single year (as from weather) can have a tremendous influence on variety performance.
Single-site summaries are also available and provide data across multiple years. These summaries allow more customized exploration of the data and also allow users to examine genotype by environment patterns in the data. (See heat map below.)
Both interactive sites have features that allow users to view, filter, and sort information. For the best experience, we recommend viewing these sites using a laptop or desktop computer with an up-to-date version of Firefox, Chrome, or Microsoft Edge web browser. (Microsoft Explorer will not work.) All results can also be viewed and downloaded as static tables and figures, with additional information about site characteristics and crop management here.
As we usher the 2019 harvest season, the 2019-20 small grains season is upon us. Don't forget to attend the Delta corn and small grains field meeting on October 15th. I wish everyone fruitful harvest and planting seasons!