Hope you are all enjoying the summer so far and keeping busy. Although, we’re about 2 months away from the Fall produce season, it’s never too early to begin thinking of IPM strategies you will be using to battle key insects next season. This includes keeping track of their typical activity during June, July, and August. Below is a short discussion detailing individual pests. 
 
Aphids:    The major aphid species that are important in produce crops each spring include green peach aphid, foxglove aphid and lettuce aphid.  These species are considered cool season pests and are biologically most active during the winter and spring when temperature average around (55-65 F). We do not find them on summer crops as the high temperatures prohibit their activity. They essentially become extinct each summer only to reappear in the fall to infest crops in Oct-Dec migrating into the desert via N-NW winds that occur after the monsoons.
 
Diamondback Moth (DBM):  Another key pest that disappears each summer but for a different reason than for aphids. The host range of DBM is limited to only brassica crop and plants. Although brassica weeds are common during the winter, they occur during the summer due to high temperatures and dry conditions. Thus, like aphids, DBM populations from the previous spring season become “extinct” during the summer when brassica crops and weeds are absent. They reappear each fall migrating in on high winds associated with tropical storms from Mexico, or arrive into the region on infested brassica transplants from California.
 
Whiteflies:       A resident pest that occurs year-round in the desert. As a warm season pest, whiteflies are most abundant on fall produce crops, and seldom a problem during the winter and spring. Peak abundance occurs during the summer months on cotton, and again in September and October on fall brassica, leafy vegetables and fall melons.  Thus, it is important to control whiteflies in cotton prior to defoliation to prevent large migrations onto fall produce crops. In addition, whiteflies can be found on several weeds such as purslane, goosefoot, ground cherry, and sunflowers. Sanitation in and around fields being prepped for fall plantings is important. Preventatively, growers should consider applying soil, system insecticides such as imidacloprid or Verimark to Fall produce crops.

Beet Armyworm (BAW):  A warm-season pest that occurs year-round in the desert. They tend to reach peak abundance twice a year. Generally, the most important peak is in September and October when weather is ideal for their development, flight activity and oviposition. A second peak occurs in late spring. Activity is generally light during the summer, occurring primarily in alfalfa crops. Although BAW is known to migrate in from the south via monsoon and tropical storms, resident populations annually occur in alfalfa during the summer. Thus, to minimize BAW in fall produce crops, thorough management of BAW can potentially minimize their movement onto Fall produce crops.  Weeds are also a source of BAW (purslane, goosefoot, sunflower and Russian thistle) so sanitation in and around fields is important.
 
Western Flower Thrips (WFT):  Also a resident pest that can be found in the desert year round. WFT is most abundant on lettuce in the late spring, but peaks in abundance on alfalfa, melons and cotton is May and June. During the late summer numbers drop dramatically where thrips can be found on melons and alfalfa and weeds like goosefoot and purslane. WFT slowly move into lettuce again in early fall and are least abundant during the winter.  Sanitation of weeds during the summer can help reduce thrips abundance moving into the fall crops and weeds.
 
For more information see:   Keeping Track of Major Produce Pests During the Summer

On November 15, 2019, United States Department of Agriculture –Animal and Plant Health Inspection Service (USDA-APHIS) issued a Federal Order imposing restrictions on imports of tomato and pepper seed lots, transplants, and fruit from all countries where tomato brown rugose fruit virus exists. The order has been in effect since Friday, November 22. In addition, U.S. Customs and Border Protection (CBP) will increase inspections of tomato and pepper seed, plant, and fruit imports from countries where the virus is known to occur and will take action to keep any infected products out of the country.                     

What is Tomato brown rugose fruit virus?

Have you heard of Tobacco mosaic virus? Plant viruses in general are obligate parasites, meaning they can live only in living hosts or vectors (thrips, aphids, hoppers etc). But the members of Tobamovirus, Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV) can live in debris, greenhouse/field tools, even in soil for months. Tobacco mosaic virus (TMV) can live even in cigarette and be transmitted to plants if the person smoking touches the plants with the same fingers!? Impressive!!

Tomato brown rugose fruit virus is similar to TMV and ToMV in regards to persistence. However, resistant varieties of tomato that have TM1, TM2, and TM22 genes against TMV and TomV are not resistant to Tomato brown rugose fruit virus.                                 

History of Tomato brown rugose fruit virus (ToBRFV)

TOBRFV was first identified in Israel in 2015. Since then the virus has been found in several countries including China, Greece, Turkey, Italy, Jordan, Mexico, Netherlands, Israel and Palestine. It has been reported but eradicated in Germany. The virus takes it name from the rugose(wrinkle) symptoms on fruit (see picture). On pepper plants it causes bubbling and mosaic on leaves. In tomato plants, the leaves have fern leaf/shoestring appearance (see pic).

What does the USDA regulation mean?

The regulation requires all the tomato fruits, seeds, plant materials coming in to the United States from the countries where the virus has been reported to be certified and virus tested in the country of origin. The seed lot, fruit lot, plant materials lot has to have inspection certificate by National Plant Protection Organization of each country along with the phytosanitary certificate.

What does it mean for Yuma and Imperial Valley?

Though we don’t grow tomatoes commercially in Yuma area, we still have to be extremely careful. Especially considering the fact that a lot of us buy grocery from Mexico and the virus has been reported in Mexico. And some of us grow tomatoes and peppers in our home garden. So it is important that we do not purchase tomatoes and peppers without the inspection certificate.

Why the USDA regulation?

This is a preventative approach to restrict the entry of virus in the United States. As mentioned earlier in the article, the virus is aggressive without even needing a vector. And with no resistant varieties of tomato or pepper available as of now, the virus could be a big problem if introduced. The unmarketable fruits, and reduction in overall yield can increase the market price. Not to mention the virus has the potential to infect many other solanaceous and non-solanaceous crops.                                                                 

Where can you get your plants tested?

There are three commercial labs that can test your tomato or pepper samples for the presence of virus.

Agdia: https://www.agdia.com/

Eurofins: USA https://www.eurofinsus.com/

Cal Seed and Plant Lab: https://csplabs.com/

What do you do if you see the symptoms in your tomato and pepper plants as described in this article?

If you think your tomato or pepper has ToBRFV, please contact me (bpoudel@email.arizona.edu), or any local/state/federal plant pathologist, or any representative of USDA.

Helpful links:

Recent KYMA segment about the virus with Dr. Poudel: https://kyma.com/news/2019/11/25/tomato-industry-threatened-by-virus/

USDA stakeholder order: https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/2019/sa-11/tomato-brown-rugose-fruit-virus

FAQS: https://www.aphis.usda.gov/aphis/ourfocus/planthealth/import-information/federal-import-orders/tobrfv/tomato-brown-rugose-fruit-virus-faqs

Vol. 12, Issue 4, Published 2/22/2021

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 “Advances in Weed Control Technologies” breakout session at the 2021 Southwest Ag Summit, university experts and cutting-edge innovators will provide updates on the latest developments in automated weeding, autonomous ag robots and non-chemical weed control. The first presenter will be Tony Koselka, COO and Vice President of Engineering, Vision Robotics Corp. Tony will be giving a history on the evolution of automated thinning/weeding technologies and real-world examples of how vision systems and artificial intelligence (AI) is being used with automated weeding machines today. Following Tony will be Paul Nagel, Chief Revenue Officer, Stout Industrial Technology, Inc. Paul will be discussing AI technologies available today, their capabilities, and where the technology is headed. Jaime Eltit, Head of Commercial Farming Operations, FarmWise, Inc. will be also be discussing AI technology and how machine learning is used for robotic in-row weed control. Additionally, he will be presenting information on the latest developments in autonomous weeding robots and their application in Arizona vegetable production systems. Finally, Dr. Steve Fennimore, Weed Scientist, UC Davis will be presenting information on a novel technique for using steam heat to control sclerotinia lettuce drop, Fusarium wilt of lettuce and in-row weeds in vegetable crops.

The session will be held TOMMOROW Thursday, February 25^th from 1:30-3:30. If you are unable to attend the live session, recordings of the presentations will be available on March 2 and March 3. For those interested in CEU’s, the session offers 2 AZ/CA PCA and CCA credits. One last thing, you must be registered for the 2021 Southwest Ag Summit in order to attend the session. To register or for more information about the Southwest Ag Summit, visit https://yumafreshveg.com/southwest-ag-summit/. Hope to see you there for what promises to be an enlightening and informative session.

Although it is not vigorous or vegetative, Shepardspurse is one of the most widespread and difficult to control broadleaf weeds worldwide. I used to think that it spread when there was more alfalfa here and because it is not controlled with 2,4-DB (Butyrate & Butoxone) but it has continued to spread in vegetable crops. It likely has become worse each year because of its growth habits more than its tolerance to herbicides. It germinates from on or just below the soil surface. Herbicides that move or are placed below the surface often miss it. It is difficult to control with Kerb, for instance, because it leaches easily with overhead sprinklers. The seed is less than 0.1 inch in diameter and moves easily in wind and water. It is very small, and the cotyledon leaves are hardly ever seen. By the time you see it, it is at the 3 or 4 leaf stage. It grows rapidly in a rosette that is low to the ground and often covered by the crop. Herbicide coverage is difficult. It soon puts up a thin seed stalk and several seed pods (“purses”). Unlike many annual broadleaf weeds, it can produce several generations in one season. It can grow year round in many regions but has a difficult time surviving the summers in the low desert.

Area wide Insect Trapping Network   VegIPM Update, Vol. 15, No. 17, Aug 21, 2024
 
Results of pheromone and sticky trap catches can be viewed here.
 
Corn earworm:           
CEW moth counts decreased areawide; about average to previous years.
 
Beet armyworm:         
BAW moth counts are up in south Yuma valley and Dome valley; about average for August

Cabbage looper:           
Cabbage looper numbers are low consistent with previous years and higher temperatures.
 
Diamondback moth:      
DBM moths were not caught in any trap; average for this time of the year.
 
Whitefly:                      
Adult movement continues to decrease, average for this time of the year.
 
Thrips:                          
Thrips adult activity continues to decline, average for August.
 
Aphids:                       
Aphid movement is absent and consistent with what we typically see during the summer.
 
Leafminers:                  
Adult activity declining and average for August.