Fall melon production is underway and transplanting/direct seeding of produce crops is close behind. PCAs will soon be faced with several important insect management decisions.  As crops begin to emerge, you can expect to encounter several insect species that can potentially cause serious economic losses to crop stands.  These seedling pests include flea beetles, crickets, grasshoppers, darkling beetles, earwigs, and saltmarsh caterpillars (‘woolly worms’). These insects all have chewing mouthparts, and most are capable of consuming large amounts of leaf tissue in a short period of time. Seedling crops at the cotyledon stage are most susceptible; these pests can devour entire cotyledons or outright kill small seedlings.  If left unprotected, transplants and larger seedling plants can sustain significant feeding damage on the terminal growing points or newly emerged leaves.  Not only can this feeding stunt plant growth but can result in lack of stand uniformity and ultimately, lack of uniform maturity at harvest. Host crop sources for flea beetle, crickets and "woolly worm" infestations include several summer crops (e.g., Sudan grass, cotton, and alfalfa), volunteer melons, and weeds (e.g., purslane, pigweed). 
Flea beetles are notorious for building up on weeds, particularly purslane, and alfalfa this time of the year. Fortunately, growers have been vigilant about field sanitation, and weeds are few and far between throughout the valleys. Be aware of beetle migration from recently harvested hay adjacent to your germinating crops. Crickets have also been especially abundant this summer, so keep a sharp eye for them, particularly under sprinkler pipe. Also be on the lookout of grasshoppers this fall. They can easily sneak up on you especially if we have an active monsoon.  Salt marsh caterpillars have not been seen in years but are known to disperse from alfalfa and Pima cotton (non-Bt).  Experience suggests that melon fields planted next to these crops and weedy areas are at a high risk from these seedling pests, particularly flea beetles. As cotton and Sudan grass are harvested or terminated during the next several weeks, these seedling pests typically move to the next available host crop; lettuce, cole crops and melons.  
Fortunately, there are many registered insecticide alternatives available that can be applied via sprinkler chemigation (i.e., pyrethroids) or foliar sprays (i.e., pyrethroids, methomyl, neonicotinoids) that can cost-effectively reduce their abundance and damage to susceptible produce and melon seedlings. Additionally, insecticide seed treatments are available for lettuce and broccoli that will protect stands from flea beetles and bagrada bug (i.e., Nipsit) for 14–21 days.  For more information on insect pests of leafy vegetables and melons at stand establishment please see:

1) Management of Insect Pests at Stand Establishment on Desert Produce and Melons
2) Palestriped Flea Beetles in Leafy Vegetables and Cole Crops

Following the recent Russian invasion, many aspects of Ukraine have been reviewed.  Ukraine is often referenced to Kansas and that section of American Great Plains and I remember this comparison being made when I was an agronomy student at Kansas State University in the early 1970s.  The agricultural importance of Ukraine was impressed upon us as agronomy students then and it is important today as well.  However, colleagues of mine who are from Ukraine and some who have visited there say that Indiana is probably a better comparison in terms of landscapes and agroecosystems. 
 
Agriculture is a very important part of Ukrainian history and for many centuries, Ukraine has been considered as the “breadbasket of Europe”, similar to the Great Plains of North America.  In 2020, Ukraine's agriculture sector generated approximately 9.3% of the nation’s Gross Domestic Product (GDP). Crop farming, which accounts for 73% of agricultural output, dominates Ukrainian agriculture, according to the International Trade Administration. The country's main crops are sunflowers, corn, soybeans, wheat, and barley. In terms of global exports, Ukraine produces 18% of the world's sunflower seed, safflower, or cottonseed oil exports; 13% of corn production; 12% of global barley exports; and 8% of wheat and meslin (a combination of wheat and rye). 
 
Grain exports are a very important part of Ukraine’s economy. It has been projected that this year Ukraine was poised to export more than three-fourths of its domestic corn and wheat crop. That compares with one-fifth for the United States.  Oilseed exports have become increasingly important for Ukraine accounting for half of the world’s sunflower oil exports and is the No. 3 international rapeseed exporter. Many global oilseeds, particularly vegetable oils, have hit record-high prices within the last year and the Ukrainian situation may exacerbate that.
 
This year, Ukraine has been predicted to account for 12% of global wheat exports, 16% for corn, 18% for barley and 19% for rapeseed, (FAO and Statistics of Ukraine).  It is interesting to note that cotton production has been resumed in parts of southern Ukraine in recent years, but it is extremely small in terms planted area and productivity.

Figure 1.  Ukraine’s projected share of world exports, 2021-2022.

The weather in Ukraine is suitable for both winter and spring crops. Average annual precipitation in Ukraine is approximately 600 mm (24 inches).  Ukraine receives approximately 350 mm (14 inches) of precipitation during the growing season (April through October). Rainfall amounts are typically higher in western and central Ukraine and lower in the south and east.  The agricultural areas of Ukraine are located at ~ 48° N (Figure 2).
 
The total area of Ukraine is over 60M ha (148M acres) with about 42M ha (104M acres) under agricultural production.  Crop production systems in Ukraine include field crop cultivation, grass farming, vegetables, fruits, and nuts. Sunflowers and sugar beets are the main technical or industrial, crops. Grain production, particularly winter wheat, is extremely important in the field crop production systems of Ukraine.  Other crops include fodder, vegetable, melon, and potato crops.  Grain crops represent 46.6% of total Ukrainian crop production; industrial crops 11.7%; potato, vegetables, melon, and gourd, 6.6%; and fodder or forage crops, 35.1%. In the past, Ukrainian grain production has reached 35-45M t/year.  The major grain crops are corn, winter wheat, followed by barley, maize, rye, and oats. Leguminous plants of high protein content include peas, beans, fodder lupin, soybeans, and forage crops, (FAO and Statistics of Ukraine).
 
Ukraine has played a major role in economic and political developments in the region. Ukraine was one of the naturally richest parts of the Soviet Union and Ukraine served as a major “breadbasket” for the massive superpower, producing large amounts of small grains and corn for distribution domestically and abroad. Being such a large producer of food, Ukraine was a prime target for collectivization under Stalin and possession of the region was the cause for tension between Stalinist Russia and Nazi Germany during WWII.  Stalin imposed a program of food and crop removal in 1932-1933 from Ukrainian farmers that created a horrible famine and genocide known as the “Holodomor” that killed approximately 10M Ukrainians. Ukraine had the largest population and the highest level of economic development of all the agricultural areas that were collectivized under Stalin.  
 
Former Soviet leader Nikita Khrushchev, who led the Soviet Union from 1958 to 1964, maintained a close relationship with Ukraine.  His hometown, Kalinovka, was located seven miles from the Russian border with Ukraine, and he spent much of his life working in the Donbas region in the eastern part of the country.  After World War II, he was appointed Secretary of the Communist Party of Ukraine and played a pivotal role in rebuilding Kyiv, which had been heavily bombed by the Germans. (Clark, 2014).
 
Agriculture in Ukraine has been changing and evolving since independence from the Soviet Union was achieved in 1991, following the Soviet Union breakup. This has been a challenge in all of the former Soviet Union republics in the past 30 years and Ukraine has generally done well or better than most.  State and collective farms were officially dismantled in 2000. Farm property was divided among the farm workers in the form of land shares and most new shareholders leased their land back to recently formed private agricultural associations, (International Trade Administration and Statistics of Ukraine).  Recently, Ukraine has produced enough food to feed 400 million people in addition to its own population of 44 million.  Ukraine has experienced a nearly 10X increase in food exports over the past 20 years with more than 40% of Ukraine’s annual corn and wheat shipments have been directed to the Middle East or Africa.
 
This is only a very brief review of Ukrainian agriculture.  For those of us working in agriculture, the Ukrainian agricultural capacity is good for us to understand in relation to what is transpiring today in that nation and the impacts that may have on global markets.

Figure 2. Environmental zones of Ukraine.

References:
Clark, Trevor L., "Changes in the Portrayal of Ukrainian Agriculture 1949-1966." (2014). EKU Libraries Research Award for Undergraduates. 13. http://encompass.eku.edu/ugra/2014/2014/13
 
Food and Agricultural Association (FAO), United Nations, Rome, Italy. Ukraine Agriculture. 2012. https://www.fao.org/3/y2722e/y2722e17.htm
 
International Trade Administration – U.S. Government. https://www.usa.gov/federal-agencies/international-trade-administration
 
Statistics of Ukraine. 2009. Agriculture of Ukraine. State Statistics Committee of Ukraine. Derzhanalitinform. Kyiv. 361 pp. [in Ukrainian]. 

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.

Vol. 13, Issue 4, Published 2/23/2022

Keeping up to date with the latest developments in automated weeding machines is challenging. It’s a very fast-moving space with significant private and public investment. At the 2022 Southwest Ag Summit “Innovations in Weed Control Technologies” breakout session, university experts and cutting-edge innovators will provide updates on the latest domestic and international developments in automated weeding, autonomous ag robots, and non-chemical weed control (agenda below). The session will be held TOMMOROW Thursday, February 24^th from 1:30-3:30 pm.

As I mentioned in the last newsletter, we’ll also be demoing our band-steam applicator for controlling soilborne diseases and weeds at the Southwest Ag Summit Field Day. We’ll also have our 2^nd generation prototype band-steam applicator on display (Fig. 2). It is simpler in design and has a higher capacity steam generator as compared to our first prototype. This will increase travel speed and thereby work rate. The event is scheduled for TODAY, Wednesday, February 23^rd from  10:30 am – 4:30 pm.

For more information about the Southwest Ag Summit, visit https://yumafreshveg.com/southwest-ag-summit/.
Hope to see you there!
Acknowledgements
This work is partially funded by the Arizona Iceberg Lettuce Research Council, Arizona Specialty Crop Block Grant Program and USDA-NIFA Crop Protection and Pest Management Program.

Fig. 1. “Innovations in Weed Control Technologies” breakout session agenda at the 2022 Southwest Ag Summit. Session will be held Thursday, February 24^th at Arizona Western College, Yuma, AZ.


Fig. 2. Prototype band-steam applicator for controlling soilborne pathogens and weeds on display at the 2022 Southwest Ag Summit, Yuma, AZ. Applicator sled and trailer fabricated by Keithly-Williams Fabrication, Yuma, AZ. Steam generator provided courtesy of Simox, Contamine-sur-Arve, France.

The purpose of the survey is to provide information to help you make weed management decisions and will include weed species, location, and infestation level monitored monthly. Twenty four points have been marked for sampling. They are distributed from San Luis to Texas Hill and includes the Yuma Mesa. A three to five acre radius will be surveyed around each point and will be reported on an aerial photograph of the county. A separate map will be provided for the abundant weed species. 
It is well known that weeds can be reservoirs for insect pests such as western flower thrips sweetpotato whitefly and for insect-transmitted viruses like Cucurbit Yellow Stunting Disease Virus (CYSDV) or Inpatiens Necrotic Spot Virus (INSV). It is our hope that the survey data aids in identifying concentrations of the weeds that could serve as hosts and are possible sources of infection.

The scale used on this survey for the infestation level on each weed is color coded as follows:

Color Code	Infestation Level	Plants / acre
White	ND: Not Detected	0
Blue	P: Present	1-3 pl/ac
Yellow	L: Low	4-50 pl/ac
Orange	M: Medium	51-200 pl/a
Red	H: High	Above 200 pl/ac

We are reporting a couple of the most abundant weeds in this update. Additional Yuma county weed maps will be uploaded reported in future updates.
The next image contains the location of our 24 sampling points:

Figure 1. Location of areas surveyed

Figure 2. Nettle leaf goosefoot continues to be the most abundant weed

Figure 3. Purslane has been present year round around ditches and citrus orchards and alfalfa fields. With recent temperatures it is increasingly easier to detect it in our sampling points at the Yuma Valley. 

Figure 4. Shepherdspurse distribution up to February

Area wide Insect Trapping Network   VegIPM Update, Vol. 13 No. 12, Jun 15, 2022
Results of pheromone and sticky trap catches can be viewed here.
 

Corn earworm:            
CEW moth counts increased significantly in the past 2 weeks, considerably higher than the previous 2 summers.
 
Beet armyworm:        
Trap counts remain active in some locations (Yuma Dome Valley and Tacna) but significantly lower than last summer
 
Cabbage looper:         
Cabbage looper numbers remain low consistent with the lack of activity this fall compared to last season.
 
Diamondback moth:     
 DBM counts very light and lower than previous 2 seasons.
 
Whitefly:                      
Adult movement continuing to increase rapidly, particularly in Dome valley and Yuma Valley consistent with melon harvest.
 
Thrips:                          
Thrips adult movement highest in Dome Valley, Tacna, and Gila Valley comparable to this time last year.
 
Aphids:                       
Aphid movement has been absent for the past month similar to what we typically observe in the summer. 
 
Leafminers:                  
Adult activity has highest in Gila Valley, and above average for mid-June.