UC Cooperative Extension will offer a virtual Alfalfa IPM Workshop on December 3rd and 4th. The workshop will run from 9am to 12pm on each day. Registration is required, and there is a $25 fee to help cover our costs of delivering a workshop virtually. Continuing education credits will be offered. (5 "Other" credits from DPR and 4 "IPM" credits for CCAs.)
Day 1. December 3 (9 am - Noon PST) Weed and Pest Management Strategies
- Price & Acreage Trends -- Josh Callan, The Hoyt Report, Twin Falls, ID
- California Regulatory Update--Dennis Albiani, Ag. Management, Sacramento, CA
- Key Agronomic Strategies for Pest Management--Dan Putnam, UC Davis
- Poisonous Weeds of Concern in Alfalfa--Larry Forero, UCCE, Redding, CA
- Weed Control Strategies for Establishment and Production -- Earl Creech, Utah State University, Logan, UT
- Recent Weed Control Trials in Alfalfa--Tom Getts & Giuliano Galdi, UCCE, Susanville and Yreka, CA
- Weed Mangement Strategies for Pastures--Josh Davy, UCCE, Redding, CA
Day 2. December 4 (9 am-Noon PST) Insect, Disease Management Strategies
- Process of Pesticide Regulation in California--Aron Lindgren, DPR, Sacramento, CA
- On-Line Tools for Pest Management Information--Jose Luiz Carvalho de Souza Dias, UCCE, Merced, CA
- Management of Insecticide Resistance in Alfalfa--KEvin Wanner, Montana State Univ.
- Biological Insect Control in Alfalfa: A Case Study--Ian Grettenberger, UC Davis
- Update on Low Desert Forage Insects--Michael Rethwisch, UCCE, Blythe, CA
- Summer Worm Management--Rachael Long, UCCE, Woodland, CA
- Potential Use of Drones for Insect Management--Ken Giles, UC Davis
- Key Diseases and Management in Alfalfa--Deborah Samac, USDA-ARS, St. Paul, MN
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.
As the Covid-19 pandemic persists, and as government and University recommendations maintain that we should limit social gatherings, I have come to the conclusion NOT to hold the annual Delta field meeting at the corn variety trial this year. The trial will be harvested in the next few weeks, and I anticipate having results ready and available on this blog by early November. It is regrettable not to be able to host the meeting this year because I know that seeing a trial can have a lot of meaning and impact. Let's hope that next year brings better circumstances. Thanks for your understanding, and please don't hesitate to reach out with questions.
SIGN UP TODAY!
Date: September 23, 2020
Time: 8:30 AM - 12:00 PM
Location: Zoom Meeting
Registration: Click here to register.
Registration fee: $9.23
What: UC Cooperative Extension will provide updates on applied research in alfalfa variety, irrigation, and pest management; sorghum and its use in dairy feeding; sugar beets and safflower as winter forages; and personal protective equipment in a time of Covid-19.
Who should attend: California alfalfa and forage growers, consultants and allied industry.
Continuing education units: Applied for California Department of Pesticide Regulation (DPR), Certified Crop Adviser (CCA), and Nitrogen Management credits
Full agenda: Click here for full agenda.
For more information, please contact:
- Julia Kalika, UC ANR Program Support Unit, (530) 750-1361, email@example.com, for registration logistics questions
- Michelle Leinfelder-Miles, firstname.lastname@example.org; Nick Clark, email@example.com; Joy Hollingsworth, firstname.lastname@example.org; or Anthony Fulford, email@example.com, for program content question
This event is open to the public. Our programs are open to all potential participants. If you require special accommodations, please contact Julia Kalika, UC ANR Program Support Unit, (530) 750-1361. The registration fee covers the technological costs of providing a virtual meeting. If the fee prevents your participation, please contact firstname.lastname@example.org for a fee waiver./h2>
Last week, I visited a baby lima field in the southwest part of San Joaquin County that had overall poor pod set. Pods were filling lower in the canopy, but flowers had not set higher on the plants. The field, which was planted in late-June/early-July had an excellent stand, and ostensibly, good fertility and moisture status (Figure 1). There were two possible reasons for the poor pod set that immediately came to mind: 1) lygus damage and 2) heat stress.
I checked data from the CIMIS stations nearest to this field, which are the Brentwood and Manteca stations. Between May 1st and August 31st, the Brentwood station recorded 16 days with a temperature over 100°F, and the Manteca station recorded 9 days over 100°F. Most notably, the heatwave in mid-August struck at perfectly wrong timing. This field was about 50 days after planting, which is generally the prime time for bean flowering. The heatwave brought daytime temperatures over 105°F and nighttime temperatures that barely, if at all, dropped below 70°F. In fact, it is the high nighttime temperatures that will impair pod development by hindering pollen movement and rendering it sterile. This is not just the case for limas; it can happen with other dry beans, as shown by Rachael Long in this blog post from a couple weeks ago. Had the heatwave occurred earlier in the summer, it could have caused a split set, which is not desirable. The mid-August timing, however, means that day length is now too short for further pod development, and yield will likely be lower than expected.
Naturally, one should ask what would be considered a ‘high' nighttime temperature? Rachael remembers having a conversation roughly 20 years ago with UC dry bean breeder of that time, Steve Temple, who said that nighttime temperatures above 68°F will cause poor pod set. This is corroborated by recent work out of the University of Delaware that indicates nighttime temperatures of roughly 70°F impairing pod set. CIMIS recorded nighttime temperatures in that range. The grower indicated that some nights stayed closer to 80°F, which is the temperature at which breeders screen varieties for heat tolerance.
So, what can a grower do during a heatwave? Obviously, we can't control the weather, but it's important to ensure that beans are not moisture-stressed at bloom, and especially not when bloom occurs during a heatwave. Check the top 12 to 24 inches of the soil profile, and irrigate if the soil is dry. If in doubt about how much water is needed, check the reference evapotranspiration (ETo) and irrigate to replace at least 120 percent of your daily ETo. Daily August ETo in the San Joaquin Valley ranges from 0.2 to 0.3 inches per day, so growers would want to apply 120 percent of that amount. In the field that I visited, the crop looked very healthy and non-stressed, so there is no clear suggestion for a management practice that could have saved the set during our recent heatwave.
For more information on lima bean production in California, please see the UC production manual.