The Mexican area-wide trapping network is active at 15 locations across Mexicali and Sonora (Fig 1), giving us an early look at pest activity. Reporting frequency varies among sites, and sticky trap data for aphids, thrips, whiteflies, and leafminers are still being compiled, but these numbers offer a useful regional snapshot.

So far, diamondback moth (DBM) has shown the most ups and downs, while cabbage looper, beet armyworm, and corn earworm remain fairly low (Fig 2).

It’s still early, and the picture will get clearer as more data come in. The real value of the network is watching trends over time; the idea is to see what’s coming our way so we’re not reacting after it’s already here.

Most importantly, this work wouldn’t be possible without the cooperation and effort of our Mexican collaborators who help deploy, collect, and report from the field. We truly couldn’t do this without them, and we’re grateful for the partnership.

At the Veg IPM session at Southwest Ag Summit, I’ll share how we’re carrying this trapping network tradition forward, modernizing it and integrating it with new projects and data to strengthen IPM decision-making.

Session details below:

AFTERNOON BREAKOUT SESSION

Thursday, February 19, 2026 | 1:30 PM – 3:30 PM

Vegetable IPM

• Dr. Palumbo Veg IPM Insecticide Program: 2025–2026 Efficacy trials — Dr. Samuel Discua Duarte, Yuma Ag Center
• Insecticide Options for Insect Pest Management in Organic Vegetable Production — Dr. Wilfrid Calvin, UofA
• Area Wide Trapping Network: Program Update and Expansion — Macey Keith, UofA
• Advances in Vegetable Weed Management: Herbicides and Chemigation Strategies — Dr. Mazin Saber, UofA

*AZ and CA DPR CEUs have been approved for the Southwest Ag Summit. Check the agenda for what CEUs each breakout session offers. 

Figure 1. Locations of 15 pheromone traps across Mexicali and Sonora used to
monitor regional Lepidopteran pests. Orange circles mark each site and its trap
number.


Figure 2. Early-season pheromone trap averages (insects per trap per day)
across 15 Mexican trapping network locations. Diamondback moth has shown the
most variability, while other Lepidopteran pests remain low. 

Water and nutrient demands coincide with the fruiting cycle of most crop plants. The efficient management of irrigation water and plant nutrients is enhanced by tracking crop development in the field and making decisions on plant demand and condtion. The use of heat units (HUs) with 86/55 oF upper and lower thresholds can be applied to warm season crops in the desert Southwest in relation to the thermal environmental impacts on the development of all crop systems (Brown, 1989), including chiles, (Figures 1 and 2).

Crop Phenology Relationship to Water and Nitrogen Demand
Phenological guidelines have been developed for many crops, including New Mexico (NM) type chiles (Soto-Ortiz and Silvertooth, 2007 and Silvertooth, et al, 2010; Figure 1). This phenological guideline can be used to identify or predict important stages of crop development that impact physiological requirements. For example, a phenological guideline can help identify stages of growth in relation to crop water use (consumptive use) and nutrient uptake patterns (Figure 3).

This information allows growers to improve the timing of water and N inputs to improve production efficiency. For most crops HU based phenological guidelines can be used to project critical dates such as harvest or crop termination. Many other inputs and applications related to crop management (e.g., pest management) can be derived from a better understanding of crop growth and development patterns.

Arizona chile production, consisting of NM type chile varieties, is mostly located in Cochise County in southeastern Arizona. The 2025 Arizona chile crop has been progressing steadily in line with the basic phenological model shown in Figure 2. For a set of fields near Pearce, Arizona with several different NM type varieties and planting dates ranging from 2 – 22 April 2025, current heat unit accumulations after planting are 1,785 – 1,957 (Figure 4a-d). The crop is moving into peak bloom and the period of peak N and water demand.

This is very good time in the season to evaluate these fields in relation to current irrigation and N fertilization needs.

Figure 1. Typical relationship between the rate of plant growth and development and
temperature. Growth and development ceases when temperatures decline below the
lower temperature threshold (A) or increase above the upper temperature threshold (C).
Growth and development increases rapidly when temperatures fall between the lower
and upper temperature thresholds (B).


Figure 2. Basic phenological guideline for irrigated New Mexico-type chiles.


Figure 3. Basic phenological guideline for irrigated New Mexico-type chiles with periods
of peak water and nutrient demand, including optimum N application window.


Figure 4a. New Mexico type chile, variety Carne Duro, 31 July 2025.


Figure 4b. Crown set chiles, Carne Duro variety, 31 July 2025.


Figure 4c. Early fruit set, Carne Duro variety, 31 July 2025.


Figure 4d. Mid-canopy fruit set, Carne Duro variety, 31 July 2025.

References

Brown, P. W.  1989. Heat units.  Bull. 8915, Univ. of Arizona Cooperative Extension,
College of Ag., Tucson, AZ.

Silvertooth, J.C., P.W. Brown, and S. Walker.  2010.Crop Growth and Development for
Irrigated Chile (Capsicum annuum).  University of Arizona Cooperative Extension
Bulletin No. AZ 1529

Soto-Ortiz, R. and J.C. Silvertooth.  2007. A Crop Phenology Model for Irrigated New
Mexico Chile (Capsicum annuum L.) The 2007 Vegetable Report. Jan 08:104-122. 

It’s unfortunately a very great season to be a plant pathologist…

We have confirmed the first sample of Fusarium wilt on lettuce submitted to the Yuma Plant Health Clinic from Yuma County. The stunted seedlings looked like any other typical case of damping-off at the seedling stage. When plated on culture media, subsequently confirmed Fusarium colonies grew abundantly from the declining plant tissues. If you’re not already on guard and scouting, this is a warning that Fusarium is active in Yuma County.

Adding on to this early alert, we’ve received a surge of submissions of young brassicas to the clinic. Several severely wilted and declining plants from around Yuma County have cultured positive for Pythium, likely as an opportunistic invader coming in on the back of all the early-season rain that brought stress to seeds and young transplants. Growers may want to consider oomycides, but only if the seedling disease is first confirmed to be Pythium. Remember, many seedling diseases caused by true fungi are indistinguishable from those caused by Pythium.

If you have any concerns regarding the health of your plants/crops please consider submitting samples to the Yuma Plant Health Clinic for diagnostic service or booking a field visit with me:

Chris Detranaltes
Cooperative Extension – Yuma County
Email: cdetranaltes@arizona.edu
Cell: 602-689-7328
6425 W 8th St Yuma, Arizona 85364 – Room 109

At the 2025 Southwest Ag Summit Field Demo a couple of weeks ago, many of the latest technologies were demonstrated in the field. Most were related to pest control. Several of the technologies demonstrated are new to the Yuma, AZ area. The recent technologies presented included two types of high precision spot sprayers for weeding and applying beneficial pesticides (Fig. 1a, Fig. 1b) and an AI based lettuce thinner. Manufacturers stated the technologies will be getting even better/more versatile soon. Both precision spot sprayer companies are developing models for small lettuce so that the machines can also be used for lettuce thinning. Also new was that the AI lettuce thinner technology is being further developed so that the device can be used also be used as a weeder. Several “older” pest control technologies also seemed to garner a lot of interest. These included an implement designed for cultivating high density crops (Fig. 1d), a camera guided cultivator equipped with in-row weeding tools (Fig. 1e) and a field scale drone sprayer (Fig. 1f).

Fig. 1. Newer pest control technologies demonstrated at the 2025 Southwest Ag Summit
Field Demo included a) Ecorobotix1 Ara high precision spot sprayer, b) Verdant Robotics
Sharp Shooter, c) Niqo Robotics AI based lettuce thinner, d) Oliver high density
cultivator, e) Steketee IC Light camera guided cultivator and f) DJI Agras T50 drone
sprayer.

My name is Mazin Saber, and I serve as an Associate in Extension specializing in Weed Management at the School of Plant Sciences, University of Arizona/Yuma County Cooperative Extension, based at the Yuma Agricultural Center. My work focuses on developing innovative site-specific weed management strategies tailored to specialty crop systems in desert agriculture, aiming to establish effective and sustainable weed control programs. I currently lead a new weed control research initiative at the Yuma Agricultural Center.

My academic background includes a Bachelor’s degree in Agricultural Mechanization and a Master’s degree in Agronomy from the University of Basrah, Iraq. I also hold an M.E., and Ph.D. in Agricultural and Biological Engineering from the University of Florida, where my doctoral research focused on designing automated mechanical intra-row weed control system for row crops.

Previously, my research has involved quantitative assessment of crop water-use and salt balance in the Lower Colorado River region. By utilizing advanced tools such as Eddy Covariance to measure evapotranspiration across 14 major crops over multiple seasons on commercial farming, I have contributed to improving water use efficiency and enhancing the sustainability and competitiveness of desert agriculture.

As I build my weed management program, I am conducting an assessment survey to identify the most pressing weed management challenges. Your feedback is crucial to ensure this program meets your needs. Please take a few minutes to complete the survey using the link below.

https://uarizona.co1.qualtrics.com/jfe/form/SV_4Od09r4hPLThLz8

I am available for any discussions about weed issues on your farm and I am happy to arrange field visits or ride-alongs to better understand your specific challenges. Please feel free to reach out to me directly.

Email Mazin

As the desert vegetable season ramps up, organic growers face tough pest management challenges with limited insecticide options. To help address this, University of Arizona researchers at the Yuma Agricultural Center conducted field trials during the 2024–2025 season, testing OMRI-listed products on six key pests in leafy greens and Brassicas.

This article highlights results for products like Entrust, Pyganic, XenTari, and M-Pede, evaluated for their performance against diamondback moth, beet armyworm, whiteflies, green peach aphid, pale striped flea beetle, and western flower thrips. The results can help growers fine-tune their spray programs and make more informed decisions this season.

As we approach the start of the upcoming season, it's a perfect time to revisit irrigation efficiency strategies, a critical component for both conventional and organic cropping systems across Arizona.

Extension professionals in Central Arizona requested a resource to help growers better understand how to manage irrigation more effectively. In response, we developed a short video explaining key strategies for efficient water use, including how to integrate weather station tools into your decision-making process.

This video provides simple, practical guidance on:

• Selecting the nearest meteorological station to your farm
• Using real-time weather data to inform when and how much to irrigate
• Incorporating agronomic practices to maximize water conservation and crop performance

Arizona is fortunate to have a robust network of weather stations called Arizona Meteorological Network (https://azmet.arizona.edu/). I highly encourage you to identify the one closest to your location and start leveraging it as part of your irrigation planning and scheduling. These data-driven strategies can help you make more informed, sustainable, and profitable decisions in the field. If you have any questions or need help getting started, please feel free to reach out.

Wishing you a productive and water-wise season for your organic/conventional cropping systems ahead!

Watch the Video: Irrigation Efficiency for Farms (YouTube)

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

Corn earworm: CEW moth counts remain at low levels in all areas, well below average for this time of year.

Beet armyworm: Trap increased areawide; above average compared to previous years.

Cabbage looper:  Cabbage looper counts decreased in all areas; below average for this time of season.

Diamondback moth: DBM moth counts decreased in most areas. About average for this time of the year.

Whitefly: Adult movement beginning at low levels, average for early spring.

Thrips: Thrips adult counts reached their peak for the season. Above average compared with previous years.

Aphids:  Aphid movement decreased in all areas; below average for late-March.

Leafminers: Adults remain low in most locations, below average for March.