With the produce season essentially finished, it’s time to begin thinking about insect management in melons. Spring melon crops are rapidly growing, and so are insect pest populations. Cabbage loopers and leafminers are becoming evident in some areas, and PCAs should start ramping up their monitoring and sampling. More importantly, whitely populations are quietly becoming abundant on the spring melons of all sizes. Adults can easily be found on recently planted melons located at the Yuma Ag Center, and reports from local PCAs suggest that adult populations are beginning to show up on older plantings. As temperatures increase and crops/weeds mature, avoidance of excessive feeding from whitefly nymphs should be the primary concern on all melon types. Although CYSDV does occur in later spring melons, it is rarely yield limiting. But honeydew and sooty mold contamination on cantaloupes, mixed melons and watermelons can significantly reduce quality and marketability is whiteflies are not adequately controlled.  Our research has shown that to prevent fruit yield and quality losses on spring melons, a foliar insecticide treatment should be applied on threshold; that is, when average adult numbers exceed 2 per leaf when averaged across an entire melon field. At this level of adult abundance, immature populations are beginning to colonize. Timing sprays based on the adult threshold has been shown to significantly reduce the chance of yield / quality losses during spring harvests.  This threshold applies for the use of recommended IGRs (Courier, Knack, Cormoran, and Oberon), foliar applied neonicotinoids (Assail, Venom, Scorpion), neonicotinoid-like compounds (Sivanto prime and Transform), diamides, (Exirel and Minecto Pro) and the feeding disruptors (PQZ and Sefina).  For more information on whitefly management and available insecticides, go to these documents on Insect Management on Spring Melons: Whiteflies and Whitefly Control Chart-Spring Melons -2024. Also, be aware of honey bees and other pollinators in or around melon fields. If bees are present, be sure to carefully read labels and determine bee safety of a product before making an application in a melon field.  If applications are necessary during bloom, only apply a product that is considered bee safe (e.g., PQZ, Sefina, Sivanto, Assail). We also recommend that insecticides only be applied when honeybees are not actively working in the field (e.g. 10:00 pm – 3: 00 am).

Some major events and developments have taken place recently in the Colorado river water shortage arena.  As a result, we are entering into a series of substantial and complicated legal aspects associated with the Colorado River situation.  
As part of the SW Ag Summit that is taking place in Yuma this week, we are conducting a breakout session on Thursday, 23 February 2023 titled “Colorado River Water Shortage: Agricultural Perspectives”.
This session will provide a brief review of the background and current situation on the Colorado River and very importantly it will include perspectives from members of the lower Colorado River agricultural community including the Palo Verde Valley, the Imperial Valley, and the Yuma area irrigation districts.   
The program outline is as follows:
 
 
2023 Southwest Ag Summit
Educational Program
Thursday – February 23, 2023
 
Morning Breakout Session
9:30 am – 11:30 am
 
 

1. Colorado River Water Shortage: Agricultural Perspectives       

(Requesting 2 CCA)
 
9:30 – 10:00    Colorado River Water Shortage: Introductory Overview      
                                    Jeff Silvertooth, University of Arizona, Tucson, AZ
 
10:00 – 10:30 Colorado River Water Shortage: Palo Verde Valley Perspective
Bart Fisher, Fisher Ranch, Blythe, CA           
 
10:30 – 11:00  Colorado River Water Shortage: Imperial Valley Perspective
                        Larry Cox, Lawrence Cox Ranches, Brawley, CA
 
11:00 – 11:30  Colorado River Water Shortage: Yuma Perspective
Elston Grubaugh, Wellton Mohawk Irrigation & Drainage District, Wellton, AZ 
 
            Moderator:      Jeff Silvertooth

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 2023 Southwest Ag Summit “Innovations in Weed Control Technologies” breakout session, university experts and cutting-edge innovators will provide updates on the latest advances in high precision smart spot sprayers, towed automated weeders and autonomous weed pulling robots (agenda below). The session will be held TOMMOROW Thursday, February 23^rd from 9:30-11:30 pm at Arizona Western College in Yuma, AZ.
As I mentioned in the last newsletter, we’ll also be demoing our band-steam applicator for controlling soilborne diseases and weeds at the Southwest Ag Summit Field Demo Day (Fig. 2). It is simpler in design and has a higher capacity steam generator as compared to our first prototype. This will increase travel speed and thereby work rate. The event is scheduled for TODAY, Wednesday, February 22^nd from 10:00 am – 4:30 pm.
For more information about the Southwest Ag Summit, visit https://yumafreshveg.com/southwest-ag-summit/.
Hope to see you there!

Fig. 1. “Innovations in Weed Control Technologies” breakout session agenda at
the 2023 Southwest Ag Summit. Session will be held Thursday, February 23^rd at
Arizona Western College, Yuma, AZ.


Fig. 2. Band-steaming demo plots prior to planting in preparation for the 2023
Southwest Ag Summit Field Demo Day, February
22^nd (https://yumafreshveg.com/southwest-ag-summit/).

On Thursday February 23, 2023, the afternoon the SWAS breakout sessions dedicated to Integrated Weed Management and Impact to Desert Agriculture (Located at AS 113) will have participation from Jesse Richardson from Corteva Agriscience.  He will give us the historic perspective of Kerb Chemigation research.  Samuel Discua Duarte from the U of A has conducted a weed survey for INSV virus hosts for a couple of years and will inform the results in his lecture.
Jose L. Carvalho de Souza from the University of Arizona Maricopa Agricultural Center will give us a lecture on the management of Palmer amaranth, the King of weeds. And I will inform some of the results from our Prefar trials at the Yuma Agricultural Center.
You are cordially invited to the session as well as the other breakout Southwest Ag Summit sessions organized by our Arizona Vegetable IPM Team…hope to see you there!.
 
 

INTEGRATED WEED MANAGEMENT AND IMPACT TO DESERT AGRICULTURE
(Requesting 2 CEU and 2 CCA)
Location: AS 113
Sponsor: Green Valley Farm Supply, Inc.

1:30-2:00p Insights from Early Kerb Chemigation Research
Jesse Richardson, Corteva Agriscience, Mesa, AZ

2:00-2:30p Survey of Weeds as Hosts of INSV in Yuma County – Results From Two Year Survey
Samuel Discua Duarte, University of Arizona, Yuma,AZ

2:30-3:00p Integrated Weed Management – Palmer Amaranth
Jose L. Carvalho de Souza, University of Arizona, Maricopa, AZ

3:00-3:30p Herbicide Evaluations at Yuma Agricultural Center
Marco Pena, University of Arizona, Yuma, AZ

Moderated by Marco Pena

 Areawide Insect Trapping Network   VegIPM Update, Vol. 15, No. 16, Aug 7, 2024
 
Results of pheromone and sticky trap catches can be viewed here.
 
Corn earworm:            
CEW moth counts decreased areawide; about average to previous years.
 
Beet armyworm:        
BAW moth counts decreased; comparable to previous summers.
 
Cabbage looper:         
Cabbage looper numbers are low consistent with previous years and higher temperatures.
 
Diamondback moth:     
DBM moths were not caught in any trap; average for this time of the year.
 
Whitefly:                     
Adult movement continues to decrease, average for this time of the year.
 
Thrips:                          
Thrips adult activity continues to decline, average for early August.
 
Aphids:                       
Aphid movement is absent and consistent with what we typically see during the summer.
 
Leafminers:                   
Adult activity declining and below average for early August.