The Yuma agriculture community lost a legend with the passing of our friend and colleague, Vicki-Lynne Scott. Vicki was a friend to everyone she met and a mentor to countless people across our agricultural community, leaving a lasting impact on Yuma agriculture and University of Arizona Extension.

I was especially fortunate to work closely with Vicki these past few months as she brought me into conversations surrounding the diamondback moth challenges facing our vegetable systems. She believed in me as an entomologist and had confidence in my abilities before I fully recognized them myself. She cared deeply about helping growers and making sure the right people were at the table to move our industry forward. Vicki also loved the Veg IPM Newsletter and often referenced Dr. Jeff Silvertooth’s work and the value of University of Arizona Extension programs.

As our community moves forward, it is difficult to imagine facing these agricultural challenges without Vicki’s guidance. Her legacy will live on in the countless people she mentored and supported throughout her life.

Vicki never left any of us wondering how deeply she cared about the people and community around her. Thank you, Vicki, for believing in people, bringing us together, and leaving our agricultural community better than you found it.

Water is the first limiting factor in desert crop production systems, followed closely by bio-available nitrogen (N).  Nitrogen fertilizer application rates for desert vegetable crops typically range from ~ 150-300 lbs. N/acre.  This variation can be due to a lot of factors, including the residual soil N levels, crop rotations, length of the production cycle for the crop, etc.  
 
Due to the critical nature of N availability for the growth of a healthy and marketable crop with good yields in a timely manner, growers are alert to preventing a N deficiency in desert vegetable crop production.  Prices for fertilizer N are always a major factor in the crop production budget for any field and that is certainly turning out to be an important issue this year with higher fertilizer N prices.
 
Figure 1 shows the average North American fertilizer price gauge pattern from 2007-2021 with a distinct surge in 2021.  This surge in fertilizer prices is reminiscent of a similar pattern in 2008 and quite an increase in relation to average prices experienced in the past five years.  More specific to N fertilizer costs, Figure 2 shows the average weekly retail anhydrous prices in the U.S. 2019-2021 with a five-year average. 
 
The primary driving force in a higher average North American fertilizer price gauge is associated with N fertilizers.  Anhydrous ammonia is a good gauge for overall N fertilizer price since so many N fertilizers utilize anhydrous ammonia in the manufacturing process.  Nitrogen fertilizer price increases are being driven by the following major factors:
 

• Anhydrous ammonia plants in Louisiana were closed in September with Hurricane Ida’s landfall.  This resulted in supply disruptions.
• Natural gas prices have been increasing in recent months.  This is important because high demand of natural gas in the production of N fertilizers and it represents a major cost in manufacturing process
• On a national level, fertilizer prices are positively correlated with corn prices.  The use of corn in ethanol production has served to tighten the relationship between corn prices and fertilizer prices.
• Similar to many other products in the U.S. and abroad, general supply chain problems and labor issues associated with the COVID-19 has had a strong impact on all industries, including the fertilizer industry.

 
Collectively, this all translates to a more costly and perhaps challenging year for nutrient management in desert vegetable production systems.  These challenges can be dealt with by consideration of the 4R approach to plant nutrient application, consisting of:
 
 1.   Right fertilizer source at the
 2.   Right rate, at the
 3.   Right time and in the
 4.   Right place
 
The 4R nutrient stewardship approach utilizes the implementation of best management practices (BMPs) that optimize the fertilizer use efficiency by the crop. The primary objective of the 4R approach and BMPs is to match nutrient supply with crop requirements and to minimize nutrient losses from fields.  With higher fertilizer prices, this can be more important in crop production management for this year.

Figure 1.  North American fertilizer prices.


Figure 2. Average weekly retail anhydrous prices. Source: Progressive Farmer, 10 November 2021.

It’s been anything but a smooth Spring melon season this year. Mild winter temperatures have contributed to the persistence of weeds and whitefly populations culminating in high viral pressure observed from the very first melon plantings onward. Through a collaborative effort between the University of California, USDA, and University of Arizona we would like to invite growers, PCAs, farm managers, researchers, and other stakeholders from the desert melon production regions in California, Arizona, and Mexicali to join us for a stakeholder meeting to discuss field observations and disease management research priorities.  

This meeting will provide an opportunity to review this season’s observations and trends across production areas, hear research and strategy updates from plant pathology specialists, and, most importantly, create space for discussion among stakeholders to better understand what is happening and give input on the disease management research priorities you want to see pursued moving forward. Topics and invited speakers include:

• Bill Wintermantel (USDA-ARS) – Overview of cucurbit viruses affecting desert melon production
• Arun Babu (UCCE Imperial)– Whitefly populations and insecticide efficacy trials in Imperial Valley
• Samuel Discua (University of Arizona, Yuma) – Whitefly populations and insecticide efficacy trials in Yuma, Arizona
• Chris Detranaltes (University of Arizona, Yuma)– Viruses and other pathogens recovered from symptomatic melon plants in Yuma, Arizona
• Ana M. Pastrana (UCCE Imperial) – Viruses and other pathogens recovered from symptomatic melon plants in Imperial Valley, California

Meeting details:
Where: AgWest Imperial 485 Business Pkwy, Imperial, CA 92251
When: June 2, 2026 10:30 am – 12:30 pm (lunch to follow until 1:00 pm)

Lunch will be provided. Please register here if you plan to attend so we can have an accurate food count and seating estimate: Registration Survey

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:

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

The autonomous agricultural robot industry is an incredibly fast-moving space. Startups, established companies and academic researchers are continuously putting forth new ideas and products. It’s hard to keep up with. In November of 2020, Future Farming (Misset Publisher, BV, Doetinchem, Netherlands) published a Field Robots Catalogue that provides a comprehensive overview of the state of autonomous ag robots. The article provides brief summaries of 35 autonomous ag robots that are currently commercially available. Along with a brief paragraph about what each robot does, the article presents information about how many robots from a particular manufacturer are actively being used, the cost of the machine, and links to a video of the device in action. Most of the robots are for weed management in vegetable crops. Kill mechanisms range from spot spraying to mechanical weed removal to electrocution.  Several of the robots featured are applicable and relevant to Arizona vegetable production, and some are currently operating in the U.S. If you’re interested in ag robots and want to get up to date, this article is an excellent resource and quick read. The article can be found at the link provided below.

Title: Future Farming Field Robots Catalogue
https://misset.com/field-robots/field-robots/
Publisher: Misset Publisher, BV, Doetinchem, Netherlands.

Almost all the herbicides used on lettuce, cole crops and melons have restrictions on how soon wheat can be planted in rotation after they have been used. Experience has demonstrated, however, that safe intervals can vary considerably based upon many factors and are almost always much longer than they need to be. The most important factors are rate applied, irrigation practices and tillage. For example, when Kerb used to be banded at 2 to 4 lbs. per acre after planting and incorporated with furrow irrigation, it was common to see treated strips across wheat fields which followed. This is uncommon now that lower rates are Chemigated. We still see some Balan injury at ends of fields or in overlaps especially when sudan is planted. Wheat it not very sensitive to Prefar and carryover injury is uncommon.

VegIPM Update Vol. 17, Num. 2

Jan. 21, 2026

Results of pheromone and sticky trap catches below!!

Corn earworm:  Few CEW moths were found in traps over the last two weeks; about average for mid-January.

Beet armyworm: BAW were collected across all locations over the last two weeks; and activity slightly increased in most areas. Above average for mid-January.

Cabbage looper:  Cabbage looper moth activity remains at all locations and above average for mid-January.

Diamondback moth: Adult activity slightly decreased across most locations. About average for mid-January.  

Whitefly: Adult activity remains low across all locations, about average for this time of year.

Thrips: Thrips adult activity remains low across locations, about average for this time of year.

Aphids: Winged aphid numbers increased over the last two weeks; below average for mid-January.

Leafminers: Adult leafminer activity remained low over the last two weeks, about average for this time of season.