- Author: Michelle Leinfelder-Miles
- Author: Mark Lundy
The Delta trial was on a Gazwell mucky clay soil, which has approximately 10 percent organic matter in the top two feet of soil. Approximately 25,000 acres in the Delta have the Gazwell classification. The 2021-22 season was characterized as being very wet from October through December, followed by very dry starting in January. An atmospheric river event dropped over six inches of rain at the end of October, according to a nearby CIMIS weather station, which delayed trial planting until December 1st. Over the course of the season, the site received approximately 10 inches of rain, and the site was not otherwise irrigated. The previous crop in the field was corn, and a pre-plant soil nitrate quick test indicated adequate nitrogen fertility at planting. The field received approximately 140 lb N/ac with in-season applications.
Under the 2021-22 conditions, the top-yielding wheat varieties (Table 1) in the Delta were UC 1961 (4.1 tons/ac; 11.2% protein), WB 9725 (4.0 tons/ac; 11.9% protein), and WB 9990 (3.8 tons/ac; 12.2% protein), and the top-yielding triticale varieties (Table 2) were UC Atrea (4.2 tons/ac; 10.6% protein), APB T470308 (4.1 tons/ac; 11.0% protein), and UC Bopak (3.9 tons/ac; 11.4% protein). The barley varieties were preferentially damaged by birds, and yields were impacted. Of what was left to be harvested, the top-yielding barley varieties (Table 3) were UC 960 (2.8 tons/ac; 8.0% protein), UC 933 (2.5 tons/ac; 8.9% protein), and Ishi (2.2 tons/ac; 7.4% protein). Please see the website for complete results.
Since environmental conditions vary from location to location and year to year, we advise making variety decisions based on aggregated data from three-year summaries. The results for the Delta best align with those from the Sacramento Valley. Thus, the Delta results are incorporated into the three-year summaries for the Sacramento Valley. The UC Davis team has developed web tools that allow us to view trial data in a more interactive way. There are two websites – one with the multi-year, multi-site summary data and another that summarizes each trial individually. We recommend using the multi-year, multi-site tool for variety decision making, and we suggest using these interactive tools on a computer, rather than a phone. Please reach out if you have questions on the trials or the web tools. Happy harvest, and good luck with your small grains crops this season!
Table 1. Delta common wheat trial results.
Table 2. Delta triticale trial results.
Table 3. Delta barley trial results. This trial had severe bird damage, and results shown are only for those varieties with sufficient yield to harvest.
The Delta trial was on a Rindge muck soil, characterized by over 20 percent organic matter in the top foot of soil. Approximately 56,000 acres in the Delta have the Rindge classification (USDA-NRCS). Over the course of the season, the site received approximately 11.5 inches of rain, and the site was not otherwise irrigated. (Precipitation data is from the Staten Island CIMIS station.) The previous crop in the field was triticale during the 2016-17 season.
The results from the 2017-18 Delta trial are summarized in table form for wheat and triticale. The top-yielding wheat varieties were WB 7566 (4.6 tons/ac; 11.7% protein), LCS 12SB0224 (4.5 tons/ac; 11.6% protein), and UC Patwin 515 (4.2 tons/ac; 12.9% protein), and the top-yielding triticale varieties were WB Pacheco (5.9 tons/ac; 11.1% protein), NS Trical 115T (5.2 tons/ac; 9.3% protein), and NS Trical 158EP (4.8 tons/ac; 9.6% protein). Of note, there was volunteer triticale from the previous year that grew in the plot. We ended up only harvesting one replicate (of four) where we rogued the triticale by hand.
Since environmental conditions vary from location to location and year to year, we advise making variety decisions based on aggregated data. For example, the Delta trial had very wet conditions in 2016-17 when California received record-setting rainfall. While conditions in 2017-18 were closer to “normal”, we still suggest reviewing three-year summaries when making variety decisions. The results for the Delta tend to align better with those from the Sacramento Valley compared to the San Joaquin Valley. Thus, the Delta results are incorporated into the three-year summaries for the Sacramento Valley, available for wheat and triticale.
Over the past two years, the UC Davis team has developed web tools that allow us to view some of the trial data in a more interactive way. There are two websites – one with the multi-year summary data and another that summarizes each trial individually. We suggest using these interactive tools on a computer, rather than a phone.
Please let us know if you have questions about the trials or the web tools.
The meeting showcased the UC Davis wheat and triticale variety testing program for the Delta, and presentations were given by UC Cooperative Extension and USDA-NRCS scientists. UCCE Grains Specialist, Mark Lundy, demonstrated a soil nitrate quick test and how it can be used in small grains fertility programs. UCCE Cropping Systems Specialist, Jeff Mitchell, described tillage research taking place at the UC Westside Research and Extension Center and demonstrated how no-till plots had better soil aggregation and tilth than conventionally tilled plots. USDA-NRCS Director, Margaret Smither-Kopperl, described winter and summer cover cropping trials at the Plant Materials Center in Lockeford, CA.
Additionally, Brenna Aegerter and I described an upcoming cover cropping trial that we will conduct on Staten Island. We were awarded a CDFA Healthy Soils Program grant with our farm advisor colleagues in the Sacramento and San Joaquin Valleys – Sarah Light, Amber Vinchesi, and Scott Stoddard – along with Jeff Mitchell and Will Horwath at UC Davis. On Staten Island, we will trial legume cover cropping versus no cover cropping treatments for soil health properties, greenhouse gas emissions, and grain yield from 2018-2020.
The trial will take place in a field that is in small grains (wheat and triticale) rotations, with soil classification Valdez silt loam. Cover cropping will take place in the summer months following the small grains harvest. Initial soil sampling will take place after wheat harvest and subsequent tillage. We will take baseline soil samples, measuring bulk density, pH, salinity, total C and N, aggregate stability, infiltration, and active C (a measure of the carbon available as an energy source for soil microbial communities) in the top foot of soil. At deeper depths, we will also test bulk density and total C. We will soil sample each fall, at the end of the cover crop season, to evaluate changes in soil properties over the three years. Greenhouse gas (N2O and CH4) monitoring will allow comparative evaluations of cumulative emissions between the soil management systems. Small grains yields will also be determined.
We look forward to this trial and will share results as we have them. We want to thank Dawit Zeleke and Morgan Johnson at The Nature Conservancy's Staten Island, Margaret Smither-Kopperl and Valerie Bullard at the USDA-NRCS Plant Materials Center, and Tom Johnson at Kamprath Seed for their collaboration on this trial.
For more information on UCCE or USDA-NRCS programs, please visit the following blogs and websites:
- Author: Michelle Leinfelder-Miles
- Contributor: Mark Lundy
- Contributor: Nicolas George
Fall has arrived, and for many crops, this means that it is harvest season. For small grains, however, the season starts anew. The UC Davis small grains variety evaluations are conducted across the state, including a site in the Delta. The results of last year's evaluations are now available, and we invite you to take a look as you prepare to plant your new crop.
To understand trends over time, we suggest reviewing the 3-year summaries, which are available from the link “Yield and Protein Summary” for common wheat and triticale. These summaries indicate which varieties performed consistently well over time. For these summaries, the Delta is grouped with other Sacramento Valley locations. The data indicated that the varieties performed similarly between the Sacramento Valley and the Delta, compared to the San Joaquin Valley and the Delta. This is probably due to similar climatic considerations, like rainfall and temperature. The 3-year summaries rank the varieties for both yield and protein. In the future, rather than tables, the research team will develop an online tool to assist with variety selection that will take both yield and protein into account. Stay tuned for more information on this tool.
Keep in mind that disease ratings are important considerations. Disease ratings are found here, where “S” indicates susceptible varieties and “R” indicates resistant ones. Additionally, some of these varieties are in initial stages of testing, so not all of them are commercially available. Look for whether the variety is “released”, which is indicated on the data tables.
Barley and durum wheat were also evaluated at certain locations but not in the Delta. We will continue trialing small grain varieties in the Delta in 2018.