The University of Arizona Vegetable IPM team is dedicated to delivering science-based solutions that help desert vegetable growers protect yield and quality while reducing reliance on broadly toxic pesticides. This mission comes to life each year through the Lettuce Insect Losses & Insecticide Use Workshop, where PCA surveys provide a snapshot of pest management practices across the desert.

At this year’s Lettuce Insect Losses & Insecticide Use Workshop, survey results continue to show the industry’s steady shift toward selective, reduced-risk products, while still relying on broad-spectrum tools when necessary. Paired with intensive scouting—nearly four visits per week—this approach allows PCAs to make smarter, more sustainable decisions that protect both crops and the environment.

Bottom Line: Twenty years of lettuce IPM research have given us stronger tools and smarter choices. Advances in chemistry, combined with the leadership of experts like Dr. John C. Palumbo have built grower confidence to lead with selective, reduced-risk products—protecting today’s lettuce crops while sustaining the tools we depend on for the future.

Figure 1. Survey results from the Lettuce Insect Losses & Insecticide Use Workshop
show total desert lettuce acreage treated with insecticides across three broad categories
of toxicity and selectivity: reduced-risk/selective, broad-spectrum, and broadly toxic.

CEU Event Coming 9/3
Don’t let the season slip by without meeting your CA and AZ PCA license requirements—UA Extension will host one more major session before the season heats up.The meeting will cover the highly desired Laws and Regs CA DPR category, giving you the chance to finish your renewals before the first pest outbreak of the season (hopefully). Details below:

2025 Laws & Regulations Update
Date: Tuesday, September 3
Location: Yuma Agricultural Center
Credits: 4 CA DPR Laws (requested) | AZDA hours pending
Time: 10:30a-3:30p

Agenda can be found HERE. We will need a headcount for lunch, please RSVP to Macey via email (maceyw@arizona.edu) or text (928-580-5785). 

If your schedule doesn’t allow for in-person attendance, UA Extension also offers online, on-demand CEU videos so you can earn credits at your convenience. You can find them here: Continuing Education Units | UA Cooperative Extension

In a recent article in this space, I provided a summary of some recent work from the Dr. J S. Famiglietti program at Arizona State University (ASU). Dr. Famiglietti is a Global Futures Professor and hydrologist with the School of Sustainability, and he serves as the director for ASU’s Arizona Water Innovation Initiative.

The work I recently summarized was published in the Geophysical Research Letters journal (Abdelmohsen et al., 2025) with the American Geophysical Union (AGU). That article describes the declining groundwater supplies in the lower Colorado River basin (LCRB). The methods for conducting this analysis are described in other publications (Rodell, Famiglietti et al., 2004; Rodell, Houser et al., 2004).

Additional work from the Famiglietti group has recently been published with their findings regarding a global review of terrestrial water storage (TWS) as a critical indicator of freshwater availability. In their methodology, they again used NASA GRACE/GRACE-FO data to show that the continents have undergone unprecedented TWS loss since 2002 (Chandanpukar, et al. 2025).

Some results of this study are summarized in Figures 1 and 2 revealing areas of intense TWS loss in this century. Mexico and Central America, the desert Southwest and other areas in the United States, i.e., California and the Ogallala Aquifer on the high plains, are clearly identified as having severe depletions of TWS, both surface and groundwater. These three regions are collectively identified as one large southwestern North American-Central American mega-drying region.

This work represents one piece of an ensemble of studies conducted by Famiglietti and his colleagues in recent years (Castle, 2014; Chandanpurkar, 2021; Famiglietti, 2014; Famiglietti, 2019; Famiglietti and Ferguson, 2021; Khorrami, 2023; Mohan, 2023; Rodell, 2018; Rodell, Famiglietti, 2004; Rodell, Houser, 2004; Scanlon, 2023;Voss, 2013; and Xu, 2023). Their methods are well-established, and they have been thoroughly scrutinized and reviewed.

Important conclusions from this study show that because of the increasing aridification along with increasing demand among many areas across the entire planet between 2002 to 2024, the availability of surface water and the levels of groundwater storage have substantially decreased.

The depletion of TWS is impacting many regions of the world. These depletions are particularly severe in many arid and semi-arid regions. As surface water sources have declined with increasing aridity in many areas, that has contributed to increasing demand for groundwater resources.

The current water crisis in Iran demonstrates the degree of severity that many parts of the world are experiencing, Kowser and Nader, 2025. The basic needs for Iran in dealing with their water crisis is like many other countries and regions. The key points that need immediate attention include improved and well-integrated agronomic programs (i.e., crop-soil-water management), incentive-based polices, strict legal enforcement, and ongoing evaluation and oversight. Like many regions, including Arizona and the desert SW of the U.S., the Iranians need immediate action, both short and long-term.

Arizona agriculture will be continually forced to deal with the increasing urban population and the diminishing water supplies. The recent results coming from Abdelmohsen et al., (2025) provide a valuable assessment of groundwater supplies in the LCRB and Arizona and the importance of conservation measures. As groundwater supplies are further diminished, that will likely direct more attention surface water sources and intensify the competition for all TWS sources. The recent work from Chandanpukar, et al. (2025) further demonstrates the importance of our water conservation needs.

This also reinforces the critical need for Arizona to develop functional groundwater legislation for areas beyond the established AMAs. It is imperative that we manage the water resources we have with great care and discipline. No one is going to come save us and there are no other water resources we can draw from. We need valid and realistic information to work with (i.e. Chandanpukar et al., 2025) and we need practical and effective conservation guidelines employed.

Fig. 1. Global map of long-term TWS trends from GRACE/FO.

(A) Trends in TWS (cm year−1) from February 2003 to April 2024 (see Materials and Methods). Mega-regions (regions exceeding −0.2 cm year−1 and connecting previously reported TWS hot spots) are outlined in black and labeled 1 to 4 corresponding to the main text. (B) Zonal sum of TWS trends for all (black) and non-glaciated regions (red). Source: Chandanpukar, et al. 2025.

Fig. 2. Mapping robustness of TWS trends.

(A) Drying and wetting land regions from where the TWS trend sign has been persistent and less sensitive to the increasing GRACE/FO record length. (B) Ratio of local interannual variability of detrended TWS anomalies to their long-term local trends. The red and blue color bars indicate regions with decreasing TWS trend and increasing TWS trend from Figure 1. Source: Chandanpukar, et al. 2025.


References
Abdelmohsen, K., Famiglietti, J. S., Ao, Y.Z., Mohajer, B., & Chandanpurkar, H. A. 2025. Declining freshwater availability in the Colorado River basin threatens sustainability of its critical groundwater supplies. Geophysical Research Letters, 52,e2025GL115593. https://doi.org/10. 1029/2025GL115593

Castle, S.L., B.F. Thomas, J. T. Reager, S. C. Swenson, M. Rodell, J. S. Famiglietti. 2014. Groundwater depletion during drought threatens future water security of the Colorado River Basin. Geophys. Res. Lett. 41, 5904–5911.

Chandanpurkar, H.A., J. T. Reager, J. S. Famiglietti, R. S. Nerem, D. P. Chambers, M.-H. Lo,B. D. Hamlington, T. H. Syed. 2021. The seasonality of global land and oceanmass and the changing water cycle. Geophys. Res. Lett.48,e2020GL091248.

Chandanpukar, H.A.,Famiglietti, J.S., Gopalan, K, Wiese, D.N., Wada, Y., Kakinuma, K., Reager,J.T., and Zhang, F. 2025. Science Advances, Vol. 11, Issue 30, 25 July 2025. DOI:10.1126/sciadv.adx0298

Famiglietti, J.S. 2014. The global groundwater crisis. Nat. Clim. Chang. 4,945–948.

Famiglietti, J.S. 2019. A map of the future of water. Trend Magazine, 3 March2019.

Famiglietti, J.S. and G. Ferguson. 2021. The hidden crisis beneath our feet. Science 372,344–345.

Khorrami, M.,M. Sherzaei, K. Ghobadi-Far, S. Werth, G. Carlson, and G. Zhai. 2023. Groundwater volume loss in Mexico City constrained by In SAR and GRACE observations and mechanical models. Geophys. Res. Lett.50,e2022GL101962.

Kowsar, N. and A. Nader. 2025. Iran’s TapsAre Nearly Empty: After five straight years of drought, the country is running dry. Foreign Policy, 7 August 2025.

Mohan, C., T. Gleeson, T. Forstner, J. S. Famiglietti, I. de Graaf. 2023. Quantifying groundwater’s contribution to regional environmental-flows in diverse hydrologic landscapes. Water Resour. Res. 59,e2022WR033153 (2023).

Rodell, M., J. Famiglietti, D. N. Wiese, J.T. Reager, H. K. Beaudoing, F. W. Landerer, M.-H. Lo. 2018. Emerging trends inglobal freshwater availability. Nature 557, 651–659(2018).

Rodell, M., Famiglietti, J.S., Chen, J., Seneviratne, S. I., Viterbo, P., Holl, S., &Wilson, C. R.2004. Basin scale estimates of evapotranspiration using GRACE and otherobservations. Geophysical Research Letters, 31(20), L20504. https://doi.org/10.1029/2004GL020873

Rodell, M., Houser, P. R.,Jambor, U., Gottschalck, J., Mitchell, K., Meng, C.‐J., et al. 2004. The global land data assimilation system. Bulletin America Meteorology Social, 85(March),381–394. https://doi.org/10.1175/BAMS853381

Scanlon, B.R., S. Fakhreddine, A. Rateb, I. deGraaf, J. S. Famiglietti, T. Gleeson, R. Q.Grafton, E. Jobbagy, S. Kebede, S. R. Kolusu, L. F. Konikow, D. Long, M.Mekonnen, H. M. Schmied, A. Mukherjee, A. MacDonald, R. C. Reedy, M.Shamsudduha, C. T. Simmons, A. Sun, R. G. Taylor, K. G. Villhoth, C. J.Vorosmarty, and C. Zheng. 2023. Global water resources and the role of groundwater in a resilient water future. Nat. Rev. Earth Environ. 4,87–101.

Silvertooth,J.C. 2025. Groundwater assessment in the lower Colorado River basin. Universityof Arizona, Vegetable IPM Newsletter, Vol. 16, No. 14.

Voss, K.A., J. S. Famiglietti, M. Lo, C. R. de Linage, M. Rodell, and S.C. Swenson. 2013. Groundwater depletion in the Middle East from GRACE withimplications for transboundary water management in the Tigris-Euphrates-WesternIran region. Water Resour.Res. 49, 904–914.

Xu, L., J. S.Famiglietti. 2023. Global patterns of water-driven human migration. WIREsWater 10, e1647

Hi, I’m Chris, and I’m thrilled to be stepping into the role of extension associate for plant pathology through The University of Arizona Cooperative Extension in Yuma County. I recently earned my Ph.D. in plant pathology from Purdue University in Indiana where my research focused on soybean seedling disease caused by Fusarium and Pythium. There, I discovered and characterized some of the first genetic resources available for improving innate host resistance and genetic control to two major pathogens causing this disease in soybean across the Midwest.

I was originally born and raised in Phoenix, so coming back to Arizona and getting the chance to apply my education while helping the community I was shaped by is a dream come true. I have a passion for plant disease research, especially when it comes to exploring how plant-pathogen interactions and genetics can be used to develop practical, empirically based disease control strategies. Let’s face it, fungicide resistance continues to emerge, yesterday’s resistant varieties grow more vulnerable every season, and the battle against plant pathogens in our fields is ongoing. But I firmly believe that when the enemy evolves, so can we.

To that end I am proud to be establishing my research program in Yuma where I will remain dedicated to improving the agricultural community’s disease management options and tackling crop health challenges. I am based out of the Yuma Agricultural Center and will continue to run the plant health diagnostic clinic located there. 

Please drop off or send disease samples for diagnosis to:
Yuma Plant Health Clinic
6425 W 8th Street
Yuma, AZ 85364

If you are shipping samples, please remember to include the USDA APHIS permit for moving plant samples.

You can contact me at:
Email: cdetranaltes@arizona.edu
Cell: 602-689-7328
Office: 928-782-5879

Thank you all very much. I look forward to meeting you all soon.

It is with sadness and a sense of loss that we share the news that our friend and colleague, John Palumbo passed away last weekend. John and I have been office mates so to speak, only two doors apart, for the past 17 years. What I will miss most about John is his presence. Warren Buffet said that a key to becoming a better person was to surround yourself with people that are better than you. In other words, hangout with people who had traits and characteristics that you admire and want to emulate. John was one of those people. He made you want to be a better person. We will miss you, John. RIP.

Hi, I’m Chris, and I’m thrilled to be stepping into the role of extension associate for plant pathology through The University of Arizona Cooperative Extension in Yuma County. I recently earned my Ph.D. in plant pathology from Purdue University in Indiana where my research focused on soybean seedling disease caused by Fusarium and Pythium. There, I discovered and characterized some of the first genetic resources available for improving innate host resistance and genetic control to two major pathogens causing this disease in soybean across the Midwest.

I was originally born and raised in Phoenix, so coming back to Arizona and getting the chance to apply my education while helping the community I was shaped by is a dream come true. I have a passion for plant disease research, especially when it comes to exploring how plant-pathogen interactions and genetics can be used to develop practical, empirically based disease control strategies. Let’s face it, fungicide resistance continues to emerge, yesterday’s resistant varieties grow more vulnerable every season, and the battle against plant pathogens in our fields is ongoing. But I firmly believe that when the enemy evolves, so can we.

To that end I am proud to be establishing my research program in Yuma where I will remain dedicated to improving the agricultural community’s disease management options and tackling crop health challenges. I am based out of the Yuma Agricultural Center and will continue to run the plant health diagnostic clinic located there. 

Please drop off or send disease samples for diagnosis to:
Yuma Plant Health Clinic
6425 W 8th Street
Yuma, AZ 85364

If you are shipping samples, please remember to include the USDA APHIS permit for moving plant samples.

You can contact me at:
Email: cdetranaltes@arizona.edu
Cell: 602-689-7328
Office: 928-782-5879

Thank you all very much. I look forward to meeting you all soon.

Integrated pest management (IPM) involves the utilization of a combination of several tactics for the effective management of pests. This concept was developed by entomologists and is currently adopted by pest managers to target various pests, including insects, weeds, and pathogens. Most IMP tactics fit well in both conventional and organic crop production. It is not uncommon that most pest management techniques (for organic or conventional production) are not very effective as a stand-alone tactic. Therefore, it is essential to use a combination of tactics that will complement each other to control the pests adequately. This is like a “many little hammers” approach, where each of the management tactics is a little hammer hammering on the pests, resulting in a cumulative suppression.

When developing an IPM program, it is important to prioritize planting resistant or tolerant crop varieties and adopting agricultural practices that promote plant health and resilience. Other practices, including physical, mechanical, or biological control, can be implemented to further reduce the pest populations. It is critical to conduct regular scouting to monitor pest populations and use economic thresholds to guide insecticide application decision-making.

Figure 1. Integrated pest management cycle. 1st:pest identification; 2nd: prevention;
3rd: monitoring; 4th: select options; 5th: control action; 6th: evaluation.

Below are some IPM tactics that can be considered in your organic IPM programs:

• Resistant varieties: Resistant varieties are crucial for effective IPM in organic crop production. When available, the use of resistant varieties should be the first line of defense against pests. Resistant varieties help save on production costs and mitigate environmental impacts associated with insecticides and their applications.

• Cultural control: Cultural control includes cropping systems (trap cropping and push-pull), planting date (early planting or late planting), crop rotation, and growing of crop varieties with early maturity traits. Implementing trap cropping and/or push-pull systems can help divert insect pests. Early or late planting, crop rotation, and variety with early maturity traits can help mitigate damaging insect pest pressures.

• Scouting: Proper and timely scouting helps determine the levels of pest infestations, allowing the pest manager to trigger control action in a timely fashion. Scouting also helps to prevent unnecessary insecticide applications.

• Economic thresholds: The economic threshold determines the pest or injury level at which control action should be taken. The economic threshold works side by side with scouting. This helps to determine when a management action should be triggered, allowing a reduction of unnecessary insecticide utilization, which will consequently help in delaying or mitigating resistance.

• Physical/mechanical control: This method includes establishing physical barriers, plowing, and sanitation (elimination of volunteer crops and other potential hosts). Plowing can help to bury soil insect pests deep into the ground, directly kill them, and expose soil insects to adverse weather conditions, birds, and other predators, which will adversely impact these pest populations.

• Biological control: This method involves using insect pests’ natural enemies, including predators such as spiders, lady beetles, syrphid fly larvae, big-eyed bugs, pirate bugs, lacewing larvae, and parasitoids such as parasitic wasps and flies.

• Bioinsecticides: Bioinsecticides are based on botanical extracts, entomopathogenic fungi, entomopathogenic bacteria, or entomopathogenic viruses that have adverse effects on insect pests. Entrust, Bt (Dipel, XenTari, Agree), Pyganic, Aza-Direct, M-Pede, Celite, Surround, Botanigard, Botanigard maxx, Venerate, and more are commonly used insecticides for insect pest control in organic crops.

Implementing IPM will result in economic benefits while preserving the environment and reducing negative impacts on human health. In other words, IPM aims at managing pests in an economically viable, socially acceptable, and environmentally safe manner. It is important to note that not all the IPM tactics are always viable in all situations, and IPM is not a one-size-fits-all solution. 

Therefore, the selection of management techniques for an IPM program should be done on a case-by-case basis.

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)

Trapping Network Continues with New Expansion

The Arizona Iceberg Lettuce Research Council has awarded funding to continue Dr. John Palumbo’s area-wide insect trapping network. For years, this system has provided PCAs and growers with real-time pest monitoring to guide sustainable management decisions.

New this year, the network is expanding into northern Mexico through partnerships with local cooperators. Their involvement allows us to track pest pressures across the border, showing where insects are coming from and giving Arizona growers an early warning of what to prepare for in the fall.

In the meantime, we’ll share general trapping updates, but soon the newsletter will once again feature the historical data and graphs that PCAs and growers have come to rely on.

Results of pheromone and sticky trap catches coming soon!!

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

Beet armyworm: Numbers remain low in all areas; below average compared to previous years.

Cabbage looper: Cabbage looper counts remain low in all areas; about average for this time of season.

Diamondback moth: DBM moths were not caught in any trap. Normal for this time of the year.

Whitefly:  Adult movement increased at all sites, about average for this time of year.  

Thrips: Thrips adult activity continues to increase, average for August.

Aphids: Aphid movement is absent and consistent with what we typically see during the summer.

Leafminers: Adult activity increasing and about average for August.