The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state. 

View a recording of the OSU Extension Bi-Weekly Fruit & Vegetable Report updates from 7-14-2023 at:

Ag Robotics

  An exciting new area in agricultural innovation is the field of ag robotics. Integrating robotic implements into modern farming addresses numerous issues that hit specialty crop production particularly hard, such as the price, availability, quality, and dependability of farm labor. Autonomous equipment offers the possibility of achieving consistent, reliable results to routine fruit & vegetable production operations. 

  A recent field tour in Ontario put on by the Ag Robotics Working Group showcased a number of new robotic farming equipment from companies such as Naio Technologies, Agrointelli, Korechi Innovations Inc., and Carbon Robotics. The machines demonstrated at the event were mostly autonomous carriers for implements like planting units, cultivation tools, mowers, soil samplers, disease monitoring sensors, etc. This multi-functionality makes the robots more versatile than if they were designed to only perform a single task. At the field tour, the Carbon Robotics laser weeder stood out as the only machine that needed to be pulled/powered by a tractor. However, the laser weeder’s strength lies in its selectivity – the equipment was capable of differentiating weeds from the crop with “deep-learning-based computer vision”. Upon recognition, thermal lasers target the weed’s growing point while leaving the crop unscathed. The laser weeder that was demonstrated was not autonomous in its mobility, but in its ability to identify weeds for termination (and continuously improve its ID ability through experience) using AI programs.

  What was striking about the field day was that many of the stops were not at testing facilities or factory floors. They were at farms where the robots were already out in the field working, performing tasks like strip tillage and cultivation. While the concept of a robot may still seem like a futuristic notion, their use in modern agriculture is becoming more established by the day and is leading to new possibilities for fruit and vegetable production, in the Midwest and across the globe. 

Current developments in ag robotics – top to bottom: Naio Oz autonomous farming assistant, Agrointelli Robotti field robot, Naio Ted autonomous finger cultivator for vineyards, and laser weeder from Carbon Robotics uses AI to recognize and terminate weeds. Photos from Chris Galbraith, OSU Extension. 

Rely 280 Label Update

The EPA has released a new supplemental label for Rely 280 herbicide (glufosinate) for controlling weeds in row middles with a hooded sprayer or for use as a burndown prior to transplanting for cantaloupe, cucumber, summer squash, watermelon, tomato, and peppers. This supplemental label is good through December 1st, 2025. Contact your local BASF technical service representative for more information on restrictions and to obtain the label. 

Herbicide Drift 

Thomas Becker, Lorain County Educator
  Over the course of the last month or so, there have been a number of calls about vegetable plants that don’t look very thrifty. They aren’t really showing signs of a disease, but the foliage looks distorted or twisted, and the plant just isn’t growing like it was before. One thing to be looking out for this time of year is damage from herbicide drift. If you suspect damage from herbicide drift, one of the first things to do is consider the potential sources of the drift. This can be difficult, as growth regulators like 2, 4-D, can volatilize and travel quite a long way. Chemicals like this are used in the lawn care and agriculture industries, or may even be used by homeowners. It is important that if you suspect herbicide injury, you consider what has been done on your own property and then have conversations with neighbors to see if you can determine the source of the drift. There are certain crops that are more susceptible to herbicide drift. The list includes but is not limited to grapes, tomatoes, fruit trees, watermelon, and certain ornamentals. Some of the signs of herbicide drift are distorted growth, leaf cupping, chlorosis, and the death of the plant in severe cases. Symptoms can vary depending on the chemical that was applied. If the plant does not die from the drift injury, yields may be reduced due to the exposure. 

Herbicide drift symptoms in tomato. Photo from Thomas Becker, OSU Extension.

If you aren’t certain that what you are dealing with is injury from herbicide drift, you can always take a plant sample to our Plant and Pest Diagnostic Clinic in Wooster to help rule out the possibility of disease. There are some viruses that cause symptoms that can look similar to herbicide drift injury. If no pathogens are detected, then there could be a good chance you are dealing with drift injury. One way to help prevent injury in the future would be to make sure you plant your crops in a site that would be protected from surrounding yards or fields that are up-wind from your property. Be careful when applying herbicide to your yard – make sure that you are following the label instructions and being mindful of the weather conditions before you spray. You can also make use of resources like DriftWatch to help report areas that grow specialty crops so that applicators are more aware of the location of these important crops. 

If you determine that you are dealing with injury from herbicide drift and can identify the source, the best course of action would be to try and work something out directly with the applicator. Beyond that, you can contact the Ohio Department of Agriculture and file a complaint as long as it is within 30 days of when the drift occurred. 

See these resources for more information on herbicide drift: 

• “Herbicide Drift and Drift Related Damage” – Penn State Extension
• “Herbicide Injury and the Problem of Spray Drift” – Ohio State University Extension
• “Noticing herbicide drift in your garden?” – University of Minnesota Extension

Crop updates

Vegetables

Cucurbits

Striped cucumber beetles, squash bugs, and squash vine borer are out at full force (check out the video below). Squash bugs can be difficult to kill. Pyrethroids and Neonicitinoids typically work best to control outbreaks. Make sure to continue to scout after application- sometimes these populations will need repeated interventions. Bacterial wilt has been sighted in cucumber, a pathogen which is vectored by cucumber beetles. Recent high winds in northwest Ohio have caused some stem damage to melons. 

 

Cucurbit downy mildew has been detected in Ontario and recently in Michigan, but has not yet been detected in Ohio. Track the spread of the disease on The Cucurbit Downy Mildew Forecast website.

Fruiting Vegetables

Viral diseases vectored by thrips and aphids are being seen on tomatoes. Aphids are exceeding economic levels in peppers, and whiteflies are also causing some damage. Please see the following piece for further information on thrips and aphids from Dr. Ashley Leach:

2023 Considerations for Aphids and Thrips

Dr. Ashley Leach, Professor and Extension Specialist, The Ohio State University

Normally, I don’t worry too much about aphids or thrips. Outbreaks of either pest typically arise as a secondary outbreak rather than being the primary pest concern. Often, aphids and thrips are checked by voracious natural enemies (Figure 1). But that’s not this year. Aphid and thrips pressure has been high across the board in 2023. In the right conditions- typically hot and dry- these insects can run rampant even in the presence of natural enemies. Although, it should be noted that natural enemies have a hard time in hot, dry conditions. For example, some Minute Pirate Bugs, will lay fewer eggs in hot, dry conditions.  So, it can be a combination of factors, natural enemies struggling to establish in the hot, dry conditions while thrips and aphids take advantage of the weather to reproduce more rapidly.

Not sure if you have thrips and/or aphids? Thrips and aphids will impact leaf tissue in different ways. Aphid infested leaves typically curl in response to infestations (Figure 2). These guys have straw-like mouthparts and will typically stay in place and suck on plant tissues (like it was a Big Gulp). Aphids are normally found on the undersides of leaves. However, they will migrate to the tops of leaves if the infestations are large enough. Thrips, however, are highly mobile. If they see you checking them out, they will move quickly to make an exit. Thrips have rasping-sucking mouthparts, so the associated damage typically looks silvery (Figure 2). When thrips feed, they are puncturing multiple plant cells which makes for a lot of damage, giving way to a “bleached” appearance by the end of the season. Many thrips are thigmotactic (Word of the day!) which basically means they like to hang out in small, tight places like flowers or plant crevices.

If you have an infestation that needs treatment, consider the following insecticide options (table below) There are some really nice -highly selective- compounds that will provide excellent control without compromising the natural enemy community. Please keep in mind that these products are not listed in all crops, and products can have varying Pre-harvest intervals (PHIs). Mind your pyrethroids. Thrips and aphid populations can flare with repeated pyrethroid applications, so I would try to avoid this insecticide class (think Warrior, Bifenture, Capture). Pyrethroid insecticides are broad spectrum products and kill resident natural enemies, thus increasing the likelihood of outbreaks. Other pests in the field may force your hand, but make sure to scout the following weeks for aphids and thrips. 

For further information on specialty crop entomology, check out Dr. Leach’s lab webpage.

Fruits

Apples

Second generation codling moths are hitting traps now, so it’s time to protect apples against codling moth infestations in fruit. San Jose Scale crawlers are likely active now, so time your sprays accordingly if you worry about infestations on fruit. Apple Maggot sprays should be timed now if traps are catching >5 flies/trap. Wooly apple aphid (WAA) populations are rising (more about aphids below). Japanese beetles have become a nuisance throughout the state. While annoying, these beetles are unlikely to cause significant damage. Typically, insecticide is recommended when we see defoliation exceeds 20-30%. 

Small fruits

  Herbicide damage from auxin herbicides (dicamba and 2,4-D) is being seen in grapes. Symptoms include twisting/curling of shoots and cupping of leaves. Learn more by checking out this factsheet from Oregon State University.

    Dr. Gary Gao has numerous berry crop research projects in development. See below for an update on a project on growing long cane raspberries:

Long Cane Raspberry Production

Dr. Gary Gao, Professor and Extension Specialist, The Ohio State University

  Long cane raspberry production is a very promising system for Ohio. Growers in Canada can produce around 22,000 lbs of raspberries per using the long cane raspberry plants from nurseries and grow them under high tunnel with fertigation. We are in the second year of our long cane raspberry project. This project is funded by an Ohio Department of Agriculture through a Specialty Crop Block Grant. Our project officially started in late 2021 and will last two years. 

  What is the long cane raspberry production? Long cane raspberry production system is a relatively new raspberry production method where raspberry bushes with long floricanes (5 feet and 10 inches) are produced in high tunnels or greenhouses, stored in coolers in autumn and winter and then shipped to growers in spring for planting and fruiting in summer. Growers can plant these “ready-made” plants with fruiting canes in a soilless media and a protected environment like a high tunnel or an unheated greenhouse or even under solar panels for fruit production in summer. This new and innovative system could help growers get around the problems of poor soil drainage that limit new cane growth and fluctuating spring temperatures that damage floricanes. The long cane production has been very popular in Europe and Canada. This approach has not been a viable option for growers in Ohio because there was not a nursery that grows and sells long cane raspberry plants.

Long cane raspberry trial plot at OSU South Centers at Piketon on July 12, 2023. Photo by Dr. Gary Gao, The Ohio State University.  

As a part of this project, I took a field trip to the Onésime Pouliot Farm in Saint-Jean-de-l’Île-d’Orléans, Québec, Canada to learn how long cane raspberry production is done on a commercial scale. Their raspberry bushes were at the peak harvest when I visited the farm on August 11, 2022. It was neat to see the “walls” of raspberries. Instead of growing them in the traditional high tunnels, the growers there designed an umbrella like structure to protect plants and fruits from rain and wind. All plants were grown in coco coir and fertigated with water-soluble fertilizers. They have been doing this for three years now. They also grow long cane raspberry plants for sale in Canada and US. I got to taste some freshly picked raspberries that day. Bonnie Lewis, Glen Mor, Kwanza, Skye, and Tulameen were the featured cultivars. Bonnie Lewis, Glen Mor, and Skye are not available in the US yet. I was very impressed by their yields and fruit quality. 

I was able to secure an import permit from USDA-APHIS in 2022. We were able to import several hundred plants from Canada in 2023. The plants came in large crates on a semi-truck in May 2023.

I am very happy to report that we made progress. We are able to grow the long cane raspberry plants extremely well. The plants are loaded with lots of green fruits as of July 18, 2023. They will start ripening around late July. Fruit harvest will likely last several weeks. I am very hopeful that the long cane raspberry production will become a standard production system for growers in Ohio and beyond.

If you want to learn more about long cane raspberry production system, register now for our free Specialty and Cover Crop Field Night by visiting: go.osu.edu/fieldnight

Come join us for a two-part, online and in-person, hybrid workshop to take a closer look at innovative production techniques for specialty crops, with a focus on long cane raspberries and tomatoes, and new types of cover crops to promote healthy soils. Part I will be online only via Zoom. Part II will be held in person at The Ohio State University South Centers in Piketon, Ohio. A meal will be included. Please see the event flyer for more information. 

 

Upcoming Events: 

July 27, 9:30 am -11:30 am and 5:00pm – 8:00pm, Specialty and Cover Crops Field Night

August 23, 8:00 am – 4:00 pm, Agriculture Technology Field Day

August 24, 5:30 – 8:00 pm, Western Ag Research Station Pumpkin Field Day

September 19 – 21, Farm Science Review

September 27, Wooster, OH, Midwest Mechanical Weed Control Field Day

December 5th – 7th, Grand Rapids, MI, Great Lakes Fruit, Vegetable, & Farm Market Expo 

January 4th – 5th, Ohio Organic Grain Conference