We’re excited to announce that the Proactive Resistance Management (PRM) app is officially live as of today! This tool has been many years in the making, with countless hours dedicated to reviewing and editing Arizona’s 1080 pesticide use data to ensure accuracy and reliability.

The PRM app translates community-scale pesticide use into easy-to-read charts that show temporal refuges—the periods when whiteflies are not exposed to a given mode of action. By visualizing these refuges, growers and PCAs can diversify chemistries, preserve susceptibility, and make more confident decisions for whitefly management across all crops.

If you’d like to learn more, or to schedule a tutorial on how to use the app with your farm or PCA team, please reach out to me.

To ensure the app is being used by the IPM decision makers—you must request access to use the app.

Request access here: http://PRM.extension.arizona.edu

Figure 1. Example temporal refuge chart from the Proactive Resistance Management
(PRM) web tool for a specific date and locality in Yuma, Arizona. Each colored bar
represents the proportion of temporal refuge (0–1) for a given Mode of Action (MoA) during
successive 90-day look-back periods. Higher refuge generally indicates fewer days of
exposure of whiteflies to that MoA, and thus lower resistance risk. These results are
interpretive, not prescriptive — refuge is one factor among many (including efficacy, crop
stage, and economics) that must guide product choice.

Click here to read more about the PRM app and learn how to put it to work in your fields.



To contact Macey Keith go to: maceyw@arizona.edu

The Colorado River Basin is managed in a complex and multi-level legal structure that involves many stakeholders. The Colorado River watershed is divided into the Upper and Lower Basins. The Upper Basin includes the states of Wyoming, Colorado, Utah and New Mexico. The Lower Basin includes Arizona, California and Nevada. A binational treaty governs the releases to Mexico from the Colorado River.

Within the overall structure of the Law of the River, the basin states and the Boulder Canyon Project Act water contractors must work collectively to address their water supply issues. In the Lower Basin, water supplies are administered by a federal water master, designated by the Secretary of the Interior working through the Bureau of Reclamation. In the Upper Basin, the Upper Colorado River Commission serves in the role of administering compliance with the 1922 Colorado River Compact. In addition, every basin also has its own unique set of law governing rights that apply within those states.

The 2007 Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for both Lake Powell and Lake Mead are set to expire in 2026. The seven Colorado River Basin states and stakeholders must work together to develop the new criteria that will replace those guidelines. At present, there is a gridlock in those negotiations between the Upper and Lower Basin states and it must be resolved in 2025 to replace those guidelines expiring in 2026.

As part of the 2025 SW Ag Summit program on Thursday, 20 February on the campus of Arizona Western College, two sessions will be held addressing the future of the Colorado River and management plans for water allocations that will be very important for agriculture in the lower Colorado River Valley in the next decade. This will include a keynote session in the morning and a breakout session will follow. The schedule for these two sessions is listed below.

Keynote Program, 7:30 a.m., 20 February 2025, College Community Center (3C)

The Future of the Colorado River

• Jeff Silvertooth, University of Arizona
• Tom Buschatzke, Director at Arizona Department of Water Resources
• J.B. Hamby, Chairman of the Colorado River Board of California and Colorado River Commissioner

 

Breakout Session – Colorado River Update, 9:30 a.m. MAC 106

Outlook on Basin wide Negotiations for the 2026 Operational Guidelines

• Introduction – Jeff Silvertooth, Moderator, University of Arizona
• Colorado River Perspectives - Principal and Water User Discussion
• Hank Auza, President, Yuma County Water Users Association
• Elston Grubaugh, General Manager, Wellton-Mohawk Irrigation and Drainage District
• J.B. Hamby, Chairman | Colorado River Board of California and Colorado River Commissioner | State of California
• Tom Buschatzke, Director, Arizona Department of Water Resources

Recently, we were notified that Dr. Bindu-Poudel is physically leaving Yuma. After approximately six years, she built a very productive and efficient plant pathology program, demonstrating strong commitment in serving the agricultural community in Yuma County and beyond. I had the opportunity to work with her as a postdoctoral researcher, and I can attest to how her work positively impacted all the aims of a land-grant university such as: education, research, and extension.

I received the great opportunity to become an Associate in Extension/Plant Pathology for the University of Arizona Cooperative Extension in Yuma. My primary goal here is to apply my professional knowledge (plant diagnosis, epidemiology, molecular biology, bioinformatics) and my passion for serving the Yuma agricultural community while learning from all of you.

At this time, I would like to take this space to say thank you for all your contributions and commitment to advancing our agricultural community, Dr. Bindu-Poudel, Once again, fair winds and following seas.

Last week, we initiated our first on-farm demonstration of soil steaming of the season with our self-propelled steam applicator. The machine is designed to inject steam into the soil and raise soil temperatures to levels sufficient to kill weed seed and soilborne pathogens (140°F for > 20 minutes). After the soil cools (< ½ day), the crop is planted into the disinfested soil.
In this trial, we are examining the viability of soil steaming for controlling weeds in organic carrot at the field scale level (plot size > ½ ac). The machine performed well in that it was able to reach target soil temperatures at reasonable travel speeds (> 0.4 mph), provide uniform temperature distribution across the bed and form nicely shaped beds suitable for subsequent planting. Stay tuned for reports of weed control efficacy, crop yield and overall profitability as compared to the grower standard. 
We are seeking collaborators to conduct similar field-scale trials/demos in Yuma, AZ. The primary objectives are to assess the viability of soil steaming at the field-scale level and obtain grower feedback on the device’s commercial potential. The machine can be adjusted to work with most bed configurations including narrow (40”, 42”) and wide (80”, 84”) beds, and is suitable for use in conventional or organic crops (soil steaming is organically compliant). To date, the device has been successfully trialed in iceberg lettuce, romaine lettuce, baby leaf spinach and carrot crops.
If you are interested in an on-farm demo of soil steaming, please let me know. I’d be happy to work with you.

Fig. 1. On-farm demonstration of a self-propelled steam applicator for weed and
disease control

Acknowledgements

This project is sponsored and funded in part by the Arizona Specialty Crop Block Grant Program and the Propane Education and Research Council (PERC). We greatly appreciate their support.

In a letter from the EPA to AMVAC dated May 2, 2024 that you can find by clicking here: https://www.regulations.gov/document/EPA-HQ-OPP-2011-0374-0116 EPA "thanks AMVAC for voluntarily proposing to discontinue DCPA use on onions".
If DCPA is not available next season our options for onion weed control are reduced. Please read the work from Carl Bell https://escholarship.org/content/qt91w4d06x/qt91w4d06x.pdf?t=lnryxp&v=lg regarding combining bensulide and pendimethalin for weeds control  in onions. He did this research due to a similar situation with Dacthal in 1996.
We tested last season 2 qts of Prefar and 0.5 pt of Prowl and the weed control looked promising.  There appears to be a synergystic effect between these products. Some phytotoxicity was observed and stand was affected. Bell reported (2001) that "a reduced crop stand does not always equal a reduced yield, since onions compensate to some extent by producing larger bulbs". 

Some PCAs are planning IPM strategies and are suggesting for green onions: "Apply Goal  early post emergence with clethodim if you have grasses then Prowl at layby".
What do you think? keep sending your comments to the Veg IPM Team and let us know what you think.

Included below is a list of organic insecticides that you can consider for your organic IPM programs. Although there are few alternative organic insecticide options, it is important to rotate when possible. Like conventional insecticides, continuous exposure to the same biopesticides may pose some risk of further reducing their efficacy and leading to the development of resistance. 

A good organic insecticide rotation practice is to alternate selective organic insecticides with broad-spectrum organic insecticides. The use of selective organic insecticides favors the increase of beneficial arthropod populations which may help to keep the pest population in check and delay repeated application of insecticides. When the population of lepidopteran pests is low, spraying Bt-based insecticides first and pyrethrin or Spinosad-based products thereafter is a good strategy. Proper insecticide rotation is important because it can help reduce insecticide application frequency, resulting in reduced crop production costs. 

 Tank-mixing can help improve the efficacy of some organic insecticides against some target pests. Tank-mixing a Bt insecticide with pyrethrin, such as Xentari + Pyganic or Dipel + Pyganic, can be an effective combination for controlling lepidopteran larvae. Additionally, combining Pyganic and a neem-based insecticide like Aza-Direct can be a favorable combination for small lepidopteran larvae. Tank-mixing Entrust (spinosad) and M-Pede can help suppress flea beetles and bagrada bugs.

Lake Mead, the nation’s largest reservoir, continues to decline to historic lows, posing a critical hydrological challenge in the Southwest with significant implications for Arizona agriculture. Prolonged and severe drought across the Colorado River Basin has led to cascading water-use reductions, including a Tier 1 shortage that has cut central Arizona’s agricultural water allocations by 65%.

The drought situation in Arizona has intensified significantly since late 2024 (see Figures 1 & 2 to determine the differences in extreme drought expansion), with extreme drought (D3) conditions spreading across much of the state. Yuma, La Paz, Maricopa, Gila, and now Greenlee counties are fully engulfed in D3 drought, while the expansion has also reached parts of Pima, Mohave, Yavapai, Navajo, Apache, Santa Cruz, Graham, and Cochise counties. This alarming trend signals a severe water deficit, raising serious concerns about its impact on agriculture, water resources, ecosystems, and communities statewide. This crisis underscores the urgent need for innovative strategies to sustain agriculture and secure water resources in the region.

One approach to addressing this crisis is implementing conservative water management, which includes adopting advanced soil moisture monitoring technologies. This raises an important question: How do you select the right soil moisture sensors for irrigation management decisions?

A wide range of soil moisture sensors are commercially available for agricultural use. However, selecting the most suitable sensor for Yuma’s arid environment, where soils are characterized by a pH greater than 8 requires careful consideration of key criteria. The selection process should focus on two critical aspects:

(a) Operational Feasibility:

• Telemetry: Real-time data transmission capabilities for remote monitoring.
• Sensor Cost: Affordability and long-term investment viability.
• Data Logging Cost: Expenses associated with data storage and accessibility.
• Ease of Operation: User-friendliness, installation requirements, and integration with existing systems.

(b) Performance Accuracy:

• Orientation: Proper sensor placement based on soil type, whether horizontal or vertical, to ensure accurate readings.

Calibration: Consideration of factory calibrations versus site-specific calibrations for improved measurement precision.

Area wide Insect Trapping Network   VegIPM Update, Vol. 14, No. 2, Jan 25, 2023
 
Results of pheromone and sticky trap catches can be viewed here.
 
Corn earworm:           
CEW moth counts are down areawide average for this time of year. 
 
Beet armyworm:          
Trap counts increased in most ll locations; about average compared to previous years.
 
Cabbage looper:          
Cabbage looper counts increased in most traps and about  average for this time of season.
 
Diamondback moth:     
 DBM moths continue to increase in all areas. About average for this time of the year.
 
Whitefly:                      
Adult movement light and is typical for this time of year. 
 
Thrips:                         
Thrips adult counts beginning to slowly increase in the past 2 weeks. Currently, below average compared with previous years.
 
Aphids:                        
Aphid movement increased significantly in North Yuma and Gila Valleys consistent with winds and storms. About average for early January.
 
Leafminers:                  
Adult activity up in many locations, and above average for January.