With spring melon harvest quickly approaching, it is probably a good idea to be extra vigilant in scouting for Lepidopterous larvae feeding on developing and mature fruit.  Beet armyworm (BAW) are becoming more abundant throughout the area. I’ve had numerous reports of BAW egg masses and larvae showing up in alfalfa and cotton, and our BAW pheromone trap counts increased sharply over the past 2 weeks, particularly in Dome Valley and Yuma Valley where traps peaked at almost 25 moths / trap / night. Although cabbage looper (CL) and corn earworm (CEW) trap counts are lower, they have been steadily increasing over the past month. So be on the lookout for these Lep species, all of which can cause significant economic damage to smooth and netted melons by feeding on developing fruit in the following manner.    
BAW: Although primarily foliage feeders, larvae will cause economic damage to watermelons and other smooth skinned melons by attacking immature fruit. The injury caused by fruit feeding is superficial, but results in cosmetic blemishes left on mature fruit (see image below) and fruit rot that may occur from secondary pathogenic organisms that enter the wounds.  The larvae will occasionally develop inside the fruit, causing abnormal development and abortion of the fruit. 
CL:     In cantaloupes, feeding on crown leaves often leaves a ragged appearance. Although this damage may not be yield limiting, larvae may move to the mature fruit and feed on the netted surface causing cosmetic blemishes (see image below).  Similarly, in watermelons and honeydews larger larvae will feed on the outer rind of maturing fruit causing large silver-colored or darkened scars.
CEW: Damage to cantaloupes and watermelons is not common, however larvae may feed on foliage and burrow in the stem. When larvae are present, they may feed on the developing fruit. Larvae are known to begin to burrow into fruit, feed only for a short time, and then move on to attack another fruit. 
Monitor fields by checking developing fruit for larvae and feeding damage. Treat with insecticides if feeding is observed on the fruit, or larvae can readily be found feeding on leaves. You have several options for controlling these Lep species.   It’s always best to spray when the populations are just building, as larvae often feeding on the melon near the soil surface and are difficult to reach with insecticides. To conserve natural enemies important for suppressing other pests (leafminers, whiteflies) consider using a selective insecticide (e.g., Intrepid, Coragen, Dipel/ Xenari). If whiteflies also require control, consider using Exirel or Minecto Pro, or tank mix-with a whitefly material (e.g., PQZ, Venom/Scorpion, Sefina, IGRs).   It is recommended that you avoid using Radiant or Lannate to prevent unnecessary exposure to western flower thrips. Whichever product you use, be aware of honeybees 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.  For more information visit Lepidopterous Larvae Control in Desert Melon Crops 2021.

Everything we eat and much of what we are surrounded by in our daily lives have a common base from water and the production of green plants.  Anything made of carbon, even if the immediate source of carbon is a petroleum-based product, has an original derivation that starts with green plants and water. 
 
Green plants perform the miraculous process of photosynthesis that captures light energy from the sun to combine with water (H₂O) taken up from the soil through the root system, carbon dioxide (CO₂) from the air, forming a simple 6-carbon carbohydrate compound (C₆H₁₂O₆), and liberating free oxygen (O₂) into the atmosphere. 
 
Photosynthesis involves a complex system of biochemical reactions, but the fundamental photosynthesis process can be reduced to very simple terms as outlined in Figure 1.

Figure 1.  Basic photosynthesis reaction.  (Source: Collegedunia).

Figure 2 offers a little more detail in the photosynthetic process and there is still more to the story.  But the essentials are outlined in Figures 1 and 2.

Figure 2.  Connections between photosynthesis and plant respiration.

The process of taking CO₂ from the atmosphere and “fixing” the carbon in a larger and more complex form as a basic carbohydrate (simple sugar compound) is referred to as “carbon fixation” and green plants provide most of this primary function in the earth terrestrial, or land-based ecosystems.  
 
Carbon fixation is conducted by organisms containing chlorophyll and green plants do most of this work.  There are also some species of algae and cyanobacteria that can fix carbon from the atmosphere.  But green plants, using energy from the water and water from the soil are the real workers in our world in this regard.
 
Water is essential in this process of fixing carbon through photosynthesis.  In fact, six units of water are required for every unit of carbohydrate that is produced (Figure 1).  
 
Additional water is used by the plant in the transpiration process, which is the movement of water from the soil through the root system, through the conductive tissues of the plant.  This provides for good cellular hydration and biological function.  In the transpiration process water moves out of the plant and escapes into the atmosphere as gas through the stomates, which are small openings in the underside of plant leaves (Figure 3).

Figure 3.  Plant transpiration.  Source: Premium Vector

Through this process of photosynthesis, water and green plants serve as the backbone of all terrestrial life.  These are fundamental facts and critical functions that we manage in crop production systems.  Essentially, every field with a green crop growing is a photosynthetic factory and water is always an essential component.  
 
Consumers directly benefit from the water used to produce the crops with all the fruits and vegetables that come from them.  Healthy animals require good food, which all comes from plants, i.e., alfalfa.  Everything we consume has a significant water footprint and much of that involves supporting plant photosynthesis.
 
The inescapable fact is that we need the plants, and the plants need water to grow and produce.

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.

AI is in the news all the time being touted as the most influential human innovation in history. Why? I’m not sure exactly as generally few specifics are given, but recently came across an article that gave me some insight as to what the experts are talking about. The piece focuses on a project by Google DeepMind¹: two AI robots playing soccer (Paul, A., 2024). There’s a couple of things that struck me most about the robots. The first was how human-like their behavior and actions were. They reminded me of a couple of 5-year-olds playing soccer. The second is the manner in which they learned. Unlike traditional programming methods where every action is meticulously coded, these robots were given the objective of scoring a goal and only provided instructions on how to stand up and kick a ball. The rest they taught themselves using deep reinforced learning (AI) methods. The news program 60 Minutes also reported on the AI soccer playing robots (Fig. 1). Check out the article here and the 60 Minutes segment in the video below. I think you’ll be impressed.

Fig. 1. 60 Minutes Segment: Google DeepMind demos AI training robots to play soccer / football. (Credit: 60 Minutes). References

References
Paul, A. (2024). Watch two tiny, AI-powered robots play soccer. Miami, Fla.: Popular Science. Available athttps://www.popsci.com/technology/deepmind-robot-soccer/.
____________________
[1] Reference to a product or company is for specific information only and does not endorse or recommend that product or company to the exclusion of others that may be suitable.

Why is it that the summer months we spray herbicides, and they don’t work for some weed species. 

For example, during the hot time of the day and when desert weeds are stressed for moisture even the highest rate of Glyphosate sometimes is not effective.
Some desert weeds develop physical characteristics and growth habits that equip them to survive hot and dry conditions. We have seen that some species have different response to herbicides in cool areas than our low desert. 

Weeds in the desert have a thicker skin to preserve water. The stomates, which are the pores found in the epidermis of leaves, stems, and other organs, controlling the rate of gas exchange between the internal air spaces of the leaf and the atmosphere are closed¹. Plant transpiration is reduced, and this interferes with the translocation of herbicides in the weeds.

Take as an example Purslane, which has very succulent leaves and stems and can survive incredibly high hot and dry conditions. Then when weather is more favorable it comes out of survival mode to start growth again at the presence of moisture.

Other perennial species have underground structures that help them survive such as Nutsedge and bermudagrass have tubers, and rhizomes.
Lundkvist² stated:” The conclusion is that environmental conditions that promote growth rate of the weed stand will also increase the herbicide effect. The results were based on data from two field experimental series performed at six sites in southern Sweden during 1991–1994”.



 References:
1. https://simple.wikipedia.org/wiki/Stomata
2. A. Lundkvist,
Predicting optimal application time for herbicides from estimated growth rate of weeds,
Agricultural Systems,
Volume 54, Issue 2, 1997,

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 many kinds of 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 that are approved for organic crop production are not very effective as a stand-alone tactic. Therefore, it is essential to use a combination of pest management techniques 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. When planning your IPM programs targeting pests in organic crop production, it is important to consider planting resistant/tolerant varieties, scouting regularly, implementing economic thresholds (when possible), practicing cultural control, physical/mechanical control, and biological control, and applying biopesticides when necessary. 

• 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 cause the diversion of insect pests. Early or late planting, crop rotation, and variety with early maturity traits can favor the avoidance of 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. 

• Biopesticides: Biopesticides are based on botanical extracts, entomopathogenic fungi, entomopathogenic bacteria, or entomopathogenic viruses that have adverse effects on insect pests. Entrust, Bt, Pyganic, AZA-Neem, M-Pede, Celite, and Venerate are commonly used insecticides for insect pest control in organic crops grown in Arizona. 

The implementation of IPM permits to manage pests economically 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 all the IPM tactics are not always viable in all situations (IPM is not a one-size-fits-all). Therefore, the management techniques choice for an IPM program should be done on a case-by-case basis. 

Area wide Insect Trapping Network   VegIPM Update, Vol. 15, No. 21, Oct 16, 2024

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

Corn earworm: CEW moth counts increased in most traps; about average for early October.

Beet armyworm: Trap counts increased in most areas last week, and about average for early October.

Cabbage looper: Cabbage looper trap counts still most locations, below average for this time of the season.

Diamondback moth: Adult activity increasing, particularly in the Yuma and Dome Valleys.  Above average for this time of season.

Whitefly: Adult movement increasing Tacna, Dome Valley and Yuma Valley; overall about average for early October.

Thrips: Thrips adult movement picking up in all areas, overall activity above average.

Aphids: Winged aphids beginning to show up the north Yuma and Gila Valleys; about average for early October.

Leaf miners: Adult activity light in all areas, about average for this time of season