Temperatures are still warm and worm pressure remains steady in most growing areas.   Here at the Ag Center, beet armyworm pressure is about average for early October, and still troublesome on new stands. Cabbage looper eggs are beginning to now show up. Pheromone trap counts for armyworm and loopers remain below average in most areas. However, diamondback moth larvae are present on broccoli and transplants at the Ag Center.  I’ve had several PCA reports of diamondback pressure in transplanted brassica crops in Wellton and Roll, and in the Yuma Valley. Trap catches have begun to increase also. So far, all insecticide products we’ve tested are providing good Lep control and no complaints from the field.  
 
Fortunately for local PCAs, several insecticide alternatives are available that provide excellent residual activity on Lep pests.   Perhaps equally important, many of the products have unique modes of action (MOA) that can be alternated throughout the growing season. This is important because the most fundamental way to reduce the risk of insecticide resistance is to eliminate exposure of multiple generations of Leps to the same MOA.   By using a different MOA on each subsequent spray application, you can minimize the risk of resistance by Lep larvae to these insecticide compounds. In contrast, repeatedly applying insecticide products with the same MOA for Lep control in the same area will significantly increase the risk of resistance.  This is particularly important with the Diamide group of insecticides (IRAC group 28). These products can be applied as both foliar sprays and soil systemic treatments, and currently 7 Diamide products are labeled for use in leafy vegetables - all with the same MOA (Coragen, Durivo, Besiege, Minecto Pro, Verimark, Exirel and Harvanta).  To avoid confusion among the Diamides, the IRAC group number (28) is placed on each label, adjacent to the product name.  Furthermore, applying a Diamide product (i.e., Coragen/Verimark) to the soil at planting or as a tray drench, and then subsequently applying Diamide foliar sprays (i.e., Harvanta/Besiege) on the same field is not a good idea as it can expose multiple generations of Leps to the same MOA.  For example, under ideal weather conditions, one could potentially expose 5-6 generations of BAW or DBM to the same MOA given the residual efficacy of the diamides.  That’s not a good way to use these products if you want them to remain effective.   Since the Diamides, as well as the other key products currently available (e.g., Radiant, Proclaim, Intrepid, Avaunt, Bts), are critical to effective management of Leps in leafy vegetables, PCAs should consciously avoid the overuse of any of these compounds. The most effective way to delay the onset of resistance by Leps in leafy vegetables is to consider the recommendations provided in the guidelines entitled Insecticide Resistance Management for Beet Armyworm, Cabbage Looper and Diamondback Moth in Desert Produce Crops.

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%). Variety: Deluxe (HMX2595) was seeded, then sprinkler-irrigated to germinate seed on March 20, 2024on 84 inches between bed centers. All other water was supplied by furrow irrigation or rainfall. Treatments were replicated five times in a randomized complete block design. Each replicate plot consisted of 25 ft of bed. Treatment beds were separated by single nontreated beds. Treatments were applied with a tractor-mounted boom sprayer that delivered 50 gal/acre at 100 psi to flat-fan nozzles spaced 12 in apart. 

Spray treatments were done on 05-21-2024, 05-31-2024, 06-07-2024 and 06-14-24. Powdery mildew was first seen on 06-05-24. Please see excel file for additional details.  

Disease severity of powdery mildew (caused by Sphaerotheca fuliginea and S. fusca) severity was determined 6-17-2024 by rating 10 plants within each of the four replicate plots per treatment using the following rating system: 0 = no powdery mildew present; 1 = one to two mildew colonies on leaves  ;2 = powdery mildew present on one quarter of leaves; 3 = powdery mildew present on half of the leaves; 4 = powdery mildew present on more than half of leaf surface area ; 5 = powdery mildew present on entire leaf. These ratings were transformed to percentage of leaves infected values before being statistically analyzed.

The data in the table illustrate the degree of disease control obtained by application of the various treatments in this trial. Most treatments significantly reduced the final severity of powdery mildew compared to nontreated plants. Quintec, Merivon, Tesaris, Luna Sensation, and V6M-5-14 V gave the best disease control. Phytotoxicity symptoms were not noted for any treatments in this trial.

ANR Webinar 10/17 click link for details.

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.

Area wide Insect Trapping Network

 

VegIPM Update, Vol. 10, No. 5, Mar 6, 2019

 

Results of pheromone and sticky trap catches can be viewed here

 

 

Corn earworm:           
Moth activity remains seasonably low, but noticeably increased in the North Yuma Valley.   Below average compared with previous seasons.

 

Beet armyworm:        
Moth activity remains seasonally moderate, particularly in Dome Valley, and are consistent with reports of larvae in fields.  About average compared with previous seasons.

 

Cabbage looper:         
Similarly, cabbage looper moth activity remains seasonally moderate in the Dome Valley and remains above average for this time of the year. About average compared with previous seasons.

 

Whitefly                      
Adult movement is relatively absent; typical for this time of the season.    

 

Thrips                         
Thrips activity remains seasonably low; but did spike in one location in the Yuma Valleys. Below average compared with previous seasons.

 

Aphids:                       
Area-wide aphid flights increased in the last 2 weeks. Most aphids found on traps were green peach aphid.   Above average movement compared with previous seasons.

 

Leafminers:                  
Adult activity remains seasonably low in all locations, and below average for this time of year.

 

Diamondback moth:  
Diamondback moth (DBM) counts in pheromone traps remained low in many locations with the exception of  the Yuma Valley.  Across all locations, trap counts remain higher now than trap counts recorded this time last year, but significantly lower than 2017 during the outbreak.   (See DBM Trap Network).