With the impending loss of the endosulfan registration on melons (July 2012), PCAs are faced with the difficult challenge in managing whiteflies and CYSDV on fall melons. Since the early 1990s, the synergized pyrethroids (e.g., Brigade+Thionex) have been the most efficacious insecticide treatments for control of adult whiteflies. Either insecticide product applied alone often provides only marginal adult activity, but when combined, the mixture consistently provides enhanced efficacy. This activity is a result of one insecticide active ingredient (endosulfan) interfering with the metabolic detoxification of another insecticide (bifenthrin) at its site of action in the insects nervous system. Thus, these pyrethroid tank-mixtures are effective because of the synergistic effects of certain organophosphate, carbamate, and organochlorine insecticides that bind to the active site associated with esterase enzymes responsible for detoxification of pyrethroid insecticides. Over the past several years we have been evaluating a number of OPs and carbamates as tank mix partners to be used as synergists for pyrethroids for adult whitefly control. A study just completed at the Yuma Ag Center compared several OPs, carbamates and other chemistries as synergists with pyrethroids in spring melons. The results were consistent with previous studies and showed that among the OP / Carbamate + Brigade mixtures, only Diazinon (labeled for use on Honeydews only) provided consistent adult efficacy, often comparable to Thionex+Brigade. The other OP/Carbamate mixtures evaluated in the trial were less consistent and rarely provided activity comparabale to Thionex. A new formulation of Agri-Mek SC was also evaluated, but did not consistently provide efficacy comparable to Diazinon or Thionex. Finally, Assail 30SG (applied at the high label rate) provided consistent knockdown and residual control of adults comparable to Thionex following each application. The complete results of this study can be found at:  Evaluation of Insecticide Tank-Mixtures as Alternatives to Endosulfan for Control of Sweetpotato Whiteflies in Spring Melons, 2012.

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.

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.

Contact herbicides are those that only affect the part of the weed that they “contact” They don’t move into or affect any other part of a plant. They were the first herbicides used and surprisingly, they still are better at controlling some weeds than any other products that have been developed. They usually control only small weeds with good coverage although some of them will kill large malva , Purslane and some other difficult to kill weeds. Goal, Sharpen, Treevix and Gramoxone, which are all contacts, will kill malva and purslane while systemic herbicides like Glyphosate and 2,4-D, misses them. Maestro or Bucril (Bromoxynil), also an old contact, will kill swinecress while many systemics like the growth regulators ,miss it. Glufosinate( Liberty, Rely) is a contact that is very broad spectrum and kills more grasses and broadleaves than many systemic herbicides. These all work very fast and in this age of immediate gratification ,you don’t have to wait long.  Most have little soil residual activity (except Goal, Chateau and a couple others) Goal and Chateau are contacts but used mostly preemergence to the weeds. They “ contact” the weeds when they emerge at the surface. which is a benefit where double or triple cropping is common. Most( again except Goal) are not volatile but will cause pretty clear contact injury when the spray moves to sensitive crops. Paraquat was registered in 1959 and is still a very useful tool for desiccating plants. Many restrictions have been put on its use because of its toxicity to humans.  Most contact herbicides are non-selective and will injure most living plant tissue. They are used selectively with directed spray or timing. Adjuvants are often required to increase absorption, spreading and sticking.

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

 

Corn earworm: CEW moth counts down in most traps over the last 2 weeks; about average for early October

Beet armyworm: Moth Trap counts increased in several areas last week and appear to remain active in cooler temps, and well above average for early November.

Cabbage looper: Cabbage counts peaked last week in all locations, about average for this time of the season.

Diamondback moth: Adult activity declined in the past 2 weeks ago, Below average for this time of season.

Whitefly:  Adult movement continues with the termination of melon harvests; overall about average for early November.  

Thrips: Thrips adult movement still down, overall activity below average.

Aphids:Winged aphids movement peaked in the north Yuma and Gila Valleys; above average for early November.

Leafminers: Adult activity down in most locations, below average for this time of season.