With the produce season finally finishing, now is a good time to reflect on pest issues from last fall. The bagrada bug, Bagrada hilaris, first occurred on desert cole crops at damaging levels in the fall of 2010, and has since become an established pest. In an attempt to document the severity of bagrada bug infestations on direct-seeded and transplanted cole crops, and the intensity of chemical management, we have annually surveyed growers and PCAs from Yuma, Imperial and Maricopa counties since 2010. We recently conducted our annual survey in April. Since 2010, the cole crop industry has experienced widespread bagrada bug infestations throughout the desert from September into November, although some years have been less intense than others. Last fall (2015) was the lightest year we’ve seen to date. Based on seasonal population abundance studies of adults infesting non-treated broccoli plants at the Yuma Ag Center (see graph below), bagrada bug infestations in the fall 2015 were lower than what we had observed since the pest first showed up in the desert. Estimates of stand losses from bagrada bug infestations at stand establishment in both direct-seeded and transplanted crops have decreased by more than 50% over the past 5 years. The lower losses reported in 2015 are likely due to the lighter bagrada pressure experienced last season. Plant injury, defined as plants with multiple heads, forked terminals, and/or blind terminals resulting from Bagrada feeding, was also lower in 2015 compared to previous years. These data suggest that PCAs have adopted effective management programs to protect seedling crops during stand establishment. Insecticide usage to control this pest remains high, and the percentage of acreage was treated in 2015 was consistent with previous years. Pyrethroids remain the primary product used for controlling bagrada bug adults either via chemigation or with foliar spray applications. Based on survey results, products that have contact activity appeared to provide the most effective control against bagrada adults on both direct-seeded and transplanted cole crops. However, more neonicotinoid products (Venom) are beginning to be implemented into the PCAs IPM programs. Overall, the results of the PCA survey are consistent with results obtained in research trials conducted at the Yuma Agricultural Center over the past four years. A summary of the 2010-2015 survey results can be found in the following report: Impact of Bagrada Bug on Desert Cole Crops, 2010-2015.

As part of the SW Ag Summit that is taking place in Yuma this week, we are conducting a breakout session on Thursday, 22 February 2024 titled “Colorado River Water Shortage: Agricultural Perspectives”.  This session will start at 9:30 a.m. in MAC 106 at the Arizona Western College campus.
This session will provide a brief review of the background, the current situation on the Colorado River and very importantly it will include an outlook on the current discussions among the basin states to negotiate a new compromise for the guidelines of use under conditions of water shortage.  These new guidelines will go into place at the end of 2026.  The immediate goal is to draft proposals by March 2024.
This breakout session at the Southwest Ag Summit will provide up to date information and firsthand insight into the process.  The participants are uniquely qualified to offer valuable perspectives on these issues.  This will be a very good session.
The program outline is as follows:


2024 Southwest Ag Summit
Educational Program
Thursday – February 22, 2024
 
COLORADO RIVER WATER UPDATE AND PROJECTIONS
Location: MAC106
 
9:30-10:00a.m. Colorado River Background and Introduction 
Elston Grubaugh, Wellton-Mohawk Irrigation and Drainage District
 
10:00–10:30a.m. Colorado River Situation and Future Projections
Bart Fisher, Palo Verder Irrigation District and State of California Colorado River Water Board member, Fisher Ranch, Blythe CA
 
10:30–11:00a.m. Colorado River Situation and Future Projections
Hank Auza, Yuma County Water User’s Association President and Yuma Ag Water 
Coalition representative, Barkley Co. of Arizona, Yuma AZ
 
11:00–11:30a.m. Question & Answer / Discussion
 
Moderator: Elston Grubaugh, Wellton-Mohawk Irrigation and Drainage District

This study was conducted at the Yuma Valley Agricultural Center. The soil was a silty clay loam (7-56-37 sand-silt-clay, pH 7.2, O.M. 0.7%). Spinach ‘Revere’ was seeded, then sprinkler-irrigated to germinate seed Jan 18, 2024 on beds with 84 in. between bed centers and containing 30 lines of seed per bed.  All irrigation water was supplied by sprinkler irrigation.  Treatments were replicated four times in a randomized complete block design.  Replicate plots consisted of 15 ft lengths of bed separated by 3 ft lengths of nontreated bed.  Treatments were applied with a CO₂backpack sprayer that delivered 50 gal/acre at 40 psi to flat-fan nozzles. 
 

Month	Max	Min	Average	Rainfall
January	68	42	54	1.14 in
February	73	47	59	0.50 in
March	77	50	63	0.31 in

 
Downy mildew (caused by Peronospora farinosa f. sp. spinaciae) was first observed in plots on Feb 19  and final reading was taken on February 26, 2024. Spray date for each treatments are listed in excel file with the results.   Disease severity was recorded by determining the percentage of infected leaves present within three 1-ft² areas within each of the four replicate plots per treatment.  The number of spinach leaves in a 1-ft² area of bed was approximately 144. 

The data (found in the accompanying Excel file) illustrate the degree of disease reduction obtained by applications of the various tested fungicides. Products that  provided effective control against the disease include Orondis ultra, Thrive 4 M, Fungout, Cevya, Eject and Zampro. No phytotoxicity was observed in any of the treatments in this trial.

Keeping up to date with the latest developments in automated weeding machines is challenging. It’s a very fast-moving space with significant private and public investment. At the 2024 Southwest Ag Summit “Ag Tech: Innovations in Weed Control Technologies” breakout session, university experts and cutting-edge innovators will provide updates on laser weeding, high precision smart spot sprayers, robotic/automated weeders and band steam (agenda below).The session will be held TOMMOROW Thursday, February 22^nd from 1:30-3:30 pm at Arizona Western College in Yuma, AZ.
As I mentioned in the last newsletter, there will also be a Field Demo where several of these technologies and other state-of-the-art automated weeders will be demonstrated operating in the field. The Field Demo is scheduled for TODAY, Wednesday, February 21^st. Breakfast will be served at 7:00 am and demonstrations begin at 8:00 am. The event will also be held at AWC.
We will also have our 3^rd generation prototype steam soil disinfestation machine on display at the event (Fig. 3). It is a self-propelled machine designed for commercial field scale operations. The device injects steam into the soil prior to planting to raise soil temperatures to levels sufficient to kill soilborne pathogens and weed seed (typically 140 °F > 20 minutes). We have had very good results with our previous prototypes and would like to demonstrate soil steaming to interested growers next season with the new machine. In addition to obtaining grower feedback on the viability of soil steaming, a second objective is to validate our small plot research results at the field scale level. If you are interested in the technique and would like a demo on your farm, please let me know. I would be happy to collaborate with you.
For more information about the Southwest Ag Summit, visit https://yumafreshveg.com/southwest-ag-summit/.

Fig. 1. Agenda for the “Ag Tech: Innovations in Weed Control Technologies”
educational session at the 2024 Southwest Ag Summit. The session will be held
Thursday, February 22nd at Arizona Western College, Yuma, AZ.


Fig. 2. 2024 Southwest Ag Summit Field Demo agenda. The event will
be held at Arizona Western College in Yuma, AZ.


Fig. 3. Self-propelled machine designed for injecting steam into the
soil prior to planting to raise soil temperatures to sufficient levels to
control soilborne pathogens and weed seed. Unit will be on display at
the 2024 Southwest Ag Summit, Yuma, AZ. (Photo credit: Peter de
Groot).

The SW Ag Summit is taking place in Yuma this week. We will have the Weed Control breakout session on Thursday, 22 February 2024 at 1:30 pm in room AS 115 of  the AWC campus. Here’s what are we going to cover:
Do you know what the IR-4 Project is? 
Established in 1963 by the U.S. Department of Agriculture and land-grant universities this project helps ensure that specialty crop farmers have legal access to safe and effective crop protection products and contributes to developing data necessary for the registration products for best pest management. Do we have this project in Yuma?
A Weed Scientist and Principal Biologist from IR-4 and NC State University will explain what this process of making more tools available to growers takes.
 
Additionally, we will have a representative from BASF chemical company who will present NEW WEED CONTROL TECHNOLOGIES as well as active ingredients developed by his company.
 
We all know with the loss of DCPA (Dacthal) herbicide our weed management tools were reduced. You asked the Veg IPM Team to look for ALTERNATIVES for Broccoli and Onion. We are doing some Trials at the UA Yuma Ag Center with products Such as Napropamide (Devrinol), which has the Devrinol DF XT dry formulation and the Devrinol 2-XT liquid. 
Which one is more aggressive? How does water incorporation affect it? How good is it on goosefoot, lambsquarter, knotweed?
Other treatments we are looking at on broccoli are Goal Tender, Prefar, Prowl, Treflan, Enversa, Rinskor.
For direct seeded onion we are testing Prefar, Etothron SC, Dual, a combination of PREFAR+PROWL PREEMERGERGENCE at low rates, Outlook+Prowl.
 
We would like to share our observations if you honor us coming to our session. Again, it is TOMORROW Thursday, 22 February 2024 at the Arizona Western College AS 115 room. This session will start at 1:30 pm.

Get your free copy of the Weed Seedling Identification Pocket Guide at the Yuma Agricultural Center.

Results of pheromone and sticky trap catches can be viewed here.

Corn earworm: CEW moth counts down in most traps over the last week; about average for early October.

Beet armyworm: Trap counts increased in several areas last week, and about average for early October.

Cabbage looper: Cabbage looper trap counts increased in most locations, but still below average for this time of the season.

Diamondback moth: Adult activity spiked 2 weeks ago, particularly in the Yuma and Dome Valleys, but down over the past week. Average for this time of season.

Whitefly: Adult movement increasing Tacna consistent with melon harvests; overall about average for early October.

Thrips: Thrips adult movement peaked 2 weeks ago but down ovr the past week, overall activity above average.

Aphids: Winged aphids beginning to show up the north Yuma and Gila Valleys; below average for October.

Leafminers: Adult activity increased significantly last week in several locations, above average for this time of season.