OSU Extension Bi-Weekly Fruit & Vegetable Report – October 17th, 2023

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

Biological Soil Health

When it comes to supporting healthy soils, the physical and chemical aspects of soil quality are often highlighted. However, the importance of biological activity and diversity, and how it influences soil structure and chemical properties (pH, electrical conductivity, etc.), is becoming increasingly appreciated in modern farming. As we discover more about the different microbe-microbe and microbe-plant interactions unfolding in the soil habitat, we can create better farming practices that optimize crop health and soil quality.

Three areas of soil health: physical, chemical, and biological. Image courtesy of University of Massachusetts. 

The source of and final destination of all soil life is soil organic matter (SOM). SOM consists of biological material in the soil, derived from plants, fungi, animals, and other organisms, that are in various stages of decomposition. Certain forms of SOM break down quickly and provide nutrients for crop use, others are more stable (i.e. inaccessible to microbial decay) and contribute to aggregate stability and tilth. A SOM content of 5% in mineral soils is considered high; in muck soils, SOM can be as high as 80%. Conservation ag practices like reduced tillage and cover cropping are used to support high levels of SOM for improved nutrient cycling, soil structure, and cation exchange capacity. 

The food webs that produce SOM are characterized by an astonishing diversity of soil life made up of bacteria, fungi, archaea, nematodes, protozoa, and other microfauna, as well as the larger organisms like springtails and earthworms higher up the food chain. These organisms not only drive nutrient cycling through consuming and contributing to SOM, but can influence crop health through more specialized relationships. Plant-growth promoting rhizobacteria that interact with plant roots can boost crop productivity by producing hormones, fixing atmospheric N, solubilizing P for increased availability, and inducing plant resistance to pathogens. The growing biologicals industry (biopesticides, biofertilizers, and biostimulants) is based on the premise that certain organisms benefit crop health through either direct interactions or interactions with other soil life. 

Keeping in mind how soil biodiversity and activity affect soil health through the lens of SOM and interactions between organisms can help us make decisions that support crops by maintaining a thriving, balanced soil habitat.

Examples of soil organisms at different scales – Microfauna: Azospirillium soil bacteria (top), Mesofauna: tardigrade (middle), Macrofauna: earthworm (bottom). Photos courtesy of Science Source (top), National Geographic (middle), Dan Brekke – Flickr (bottom).

Crop Updates



Plectosporium leaf blight is being detected. Continue to watch for aphids, cucumber beetles and squash bugs. Significant damage was detected within the last week in harvested pumpkins due to large populations of cucumber beetles. Aphids can still be found in green foliage, and may be spotted via large accumulations of honey dew beneath healthy foliage.

Cucumber beetles feeding on harvested pumpkins. Photo by Frank Becker, OSU Extension.

Cole Crops

Alternaria leaf spot is being observed in brassicas. This pathogen is supported by warm, wet conditions. Cultural practices for reducing alternaria pressure include increasing crop spacing for improved airflow, crop rotation, tilling under crop residue after harvest and controlling brassica weeds (shepherd’s purse, wild mustard, wild radish, yellow rocket, etc.)  to decrease disease inoculum. Treating seed with hot water prior to planting may also help  to decrease prevalence of this seed-borne pathogen. Consult the Midwest Vegetable Guide for fungicide options in Brassicas.


Hoop house tomatoes are nearing the end. Powdery mildew, bacterial diseases, aphids, and other pests are all being observed under plastic. Late blight and early blight are prevalent in remaining field tomatoes. 

Anthracnose is continuing to be an issue on peppers and tomatoes. Infested fruits rapidly decline in quality and are unmarketable. Lesions are typically observed as sunken, round lesions on the fruit. At times you may also be able to see the salmon colored spores within the lesion on the fruit. 

Anthracnose on peppers. Photo by Frank Becker, OSU Extension. 


Many orchards are nearing completion of harvest and pest monitoring traps are being taken down for the season. As tree fruits are harvested and leaves begin to fall, it may be a good opportunity to take a closer look at your trees and scout the trunk and branches for presence or evidence of insect pests such as scale and borers. Scouting for these pests now can help you make adjustments to your integrated pest management program.

October Small Fruit Updates

Dr. Gary Gao, Professor and Small Fruit Specialist, CFAES South Centers. The Ohio State University

Update on Long Cane Raspberry Project:

We are only getting a few straggling raspberries from our long cane raspberry trial at OSU South Centers in Piketon during the week of October 6, 2023. There were only enough for Gary to snack on. Pictured in the first photo is Kweli®. As you can tell from the picture, fruit color is still looking quite nice. Kweli® is an everbearing variety that is capable of producing two crops inside a high tunnel and out in the open field. Follow this link for more information on the variety: https://www.abbreeding.nl/varieties/kweli/?lang=en

We are still fine-tuning the method of growing long cane Kweli®. We just wrapped up our 2021-2023 Specialty Crop Block Grant (SCBG) funded by Ohio Department of Agriculture (ODA). There is a lot more to learn about this highly innovative production method. Fortunately, we received another SCBG from ODA to do just that!

Kweli® fruits. Photo by Dr. Gary Gao, The Ohio State University.

Gary was able to find several Tulameen raspberries from our long cane raspberry trial plot. This is definitely too late for the Tulameen harvest since it is a summer-bearing variety which does not produce fruits on primocanes. It was still neat to check them out. Earlier in the season, we harvested a lot of beautiful Tulameen fruits. Some of our grower cooperators were able to sell them for $9 per pint in a Columbus farmer’s market. Raspberry bushes in a long cane production system can produce 22,000 lbs. per acre! Tulameen is well suited for long cane raspberry production and is well known for its large fruit size and excellent taste! Follow this link – https://www.researchgate.net/publication/292928034_’Tulameen’_red_raspberry – for more information on Tulameen variety.

Tulameen fruits picked in October from our long cane raspberry trial. Photo by Dr. Gary Gao, The Ohio State University.

Late Leaf Rust on Raspberries:

Gary noticed that some of the raspberry bushes in their raspberry trial had late leaf rust. Late leaf rust on raspberry is a fungal disease. Follow link – https://ohioline.osu.edu/factsheet/plpath-fru-17#:~:text=Late%20leaf%20rust%20is%20caused,rust%20fungus%20is%20not%20systemic. -for more information on symptoms and management of this disease. Do not confuse this disease with orange rust of brambles. Fortunately, red raspberries are resistant to orange rust.

Late leaf rust on raspberries. Photo by Dr. Gary Gao, The Ohio State University.

Fall is for Figs in Ohio!

Even though fall is typically for apples, mums, and pumpkins, it is also for figs – well hardy figs for that matter. Gary has been picking hardy figs from their fig planting at OSU South Centers in Piketon from early September to now. The figs will keep ripening until frost. A high tunnel will extend the harvest season.  Our figs were from another Ohio Specialty Crop Block Grant funded by ODA a few years ago. The varieties in our trial are Brown Turkey, Hardy Chicago, and Olympian. Brown Turkey and Chicago Hardy performed the best in our trial. Follow this link https://ohioline.osu.edu/factsheet/hyg-1439 for more information.

OSU hardy fig trial. Photo by Dr. Gary Gao, The Ohio State University.

Brown Turkey figs from the hardy fig trial at OSU South Centers in Piketon. Photo by Dr. Gary Gao, The Ohio State University.

Berry Production Workshops Presented by OSU Extension in Medina County

I will be going to Medina County on Friday, October 27 to give two talks, one on blueberries and one on raspberries. Ms. Ashley Kulhanek, the Ag. and Natural Resource Educator, is organizing the program. I will show gardeners and growers how to grow blueberries and raspberries. Please call OSU Extension in Medina County at 330-725-4911 for more information and to RSVP!

This is our last bi-weekly report for the 2023 season. Thank you for reading and please feel free to direct any feedback on the report series to Chris Galbraith at galbraith.108@osu.edu.

Upcoming Events

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

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference


OSU Extension Bi-Weekly Fruit & Vegetable Report – September 28th, 2023

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 below:

Strip Tillage

Strip tillage is a form of conservation tillage that attempts to combine the benefits of no-till and conventional tillage by working only the area where the crop will be planted. Leaving residue cover over the majority of the field protects the soil against erosion and helps to build organic matter, improve aggregate stability, and boost other indicators of soil health. Working the soil in the strip zone warms the soil faster and prepares a better seedbed to support plant growth. 

Components of a strip till unit – A) lead coulter for slicing through residue, B) row cleaners for parting residue, C) shank for fracturing and lifting soil, D) berm-building coulters to shape tilled soil into strip, & E) rolling basket for creating level seedbed. Photo courtesy of Orthsman/Unverferth Manufacturing. 


Strip-till in sweet corn stubble. Photo by Chris Galbraith, OSU Extension.

While strip till targets the benefits that come with integrating the two systems, there are downsides to consider as well. These mostly involve issues with cover crop and/or residue interference with growing the crop. Vigorous cover crops need to be terminated in a timely fashion and crop development can still be delayed in strip-till if the season begins cold and wet. Pests like slugs and voles can also build-up with the increased residue cover. The cost of the equipment can also be a substantial investment which creates a barrier to entry for many growers.

Many vegetables can be grown in strip tillage systems, including cucurbits, sweet corn, snap beans, potatoes, cole crops, carrots, and more. Recent studies at Michigan State University have found a slight yield increase from strip till in vegetable crops, but many of the issues mentioned can impact this (climate, residue management, pest pressure). It is important to consider the factors that go into making strip till a successful venture in order to make the most of the equipment and the practice.

For additional info on strip till in vegetables, check out this website on strip tillage from the Cornell Small Farms Program. 

Wildlife Control in Fruits & Vegetables

This season has been severe in terms of wildlife damage in specialty crops. Animals like deer, groundhogs, voles, raccoons, and birds have caused major losses on some farms. Dr. Marne Titchnell, wildlife program director for OSU Extension, recently gave an in-depth presentation at Farm Science Review on different wildlife mitigation strategies for growers. The information and slides can be found on her blog through the link below:

Managing and Preventing Damage from Wildlife in Fruits & Vegetables

OSU Extension Center for Cooperatives

Opportunities abound for farms when it comes to teaming up to save money and improve effectiveness through joint purchasing, collaborative marketing, and other similar practices. These types of partnerships between farm businesses is captured by the cooperative or “co-op” model where growers access resources and savings by acting together and making decisions as a group in certain scenarios. The Center for Cooperatives at OSU specializes in these sorts of opportunities and can offer guidance to growers who are interested in leveraging the benefits of organizing for collaborative business purposes.

Find more information at the center’s website. Read more about the topic of collaborative marketing in this recent article on the Center of Cooperatives blog.

Crop updates


Cole Crops

Heavy cross striped cabbageworm and imported cabbageworm feeding is still being observed in some brassica plantings. Aphids have made a late season push in brussel sprouts, cabbage, cauliflower and broccoli plantings. Cabbage aphids are typically a grayish color, and are often found amongst a waxy, white secretion which covers their body. Reproduction rates of these aphids are highest in temperatures between 50-68F. Scout for these pests on the underside of younger leaves, between leaf layers and on flower buds or seed stalks. It is recommended to treat cabbage when you see 1-2% of plants infested with aphids. There are a number of products that can be used to treat aphids in cabbage including Movento, Sivanto, Assail, Exirel and Beleaf. Prioritize products that have reduced toxicity (e.g., Beleaf) which will conserve natural enemy communities. Refer to the Midwest Vegetable production guide for other options. 

Cabbage aphid infestation. Photo by Frank Becker, OSU Extension. 


Cucurbits are seeing upticks in a variety of beetles in flowers and fruit. These include corn rootworm species. Spotted cucumber beetles are active. Aphids are also beginning to be found with some more frequency in the fall vine crops. Squash bugs are also active within the crop. Most cucurbits do not have blooms in fields, so pyrethroid and carbamate applications may be applied (e.g., Sevin, Pounce, Capture). Refer to the Midwest Vegetable production guide for other options.

The pumpkin crop has been strong in Ohio this season. Many growers in northwest Ohio were able to manage downy mildew with fungicides. Plectosporium blight has been causing some problems for growers where fungicide spray coverage may not have been as thorough as desired. Most fungicide spray programs being used are adequate to limit impacts from plectosporium blight. Spray penetration into the canopy and coverage across the field is as important as selecting the right product.

Plectosporium blight on pumpkin, identified by light colored lesions on fruit, handles, and vines.  Photos by Frank Becker, OSU Extension.

Fruiting Vegetables 

Late blight has been confirmed in several tomato fields in and around Wayne County. Bacterial diseases have also begun to start, and with cool mornings and heavy dews, it will become increasingly more difficult to manage. 

Several high tunnel producers have reported dealing with broad mites/cyclamen mites in their high tunnel peppers. The mites feed on the fruit while it is still developing and their feeding damage causes the peppers to become russested and misshapen. The leaves may also appear distorted, almost as if they were drifted with herbicides. Keep in mind that these mites are in a different group than two-spotted spider mites. Therefore, it’s important to select control options that are appropriate and effective on this species. Sanitation and crop rotation are also important cultural control measures that need to be taken when dealing with mites in high tunnels.  


Although the growing season is behind us for onions, curing is still ongoing, and some growers have reported some challenges with curing. Make sure that you are providing the proper conditions for curing onions. Less than ideal conditions will result in frustrations and losses of product. Ideal conditions are warm, dry, well ventilated areas. Ideal temperature range is between 75-90F. The other factor that contributes to losses while curing is not curing the best graded onions. Curing is not an attempt to bring quality back, only preserve it. Grading hard for only the best onions to be cured will help reduce the chance that rots begin to develop. Take note of any disease or insect issues that you have observed this year and use these notes to help you next year. Onions that may have had heavy thrips loads, or untreated disease infection during the season are not going to hold up as well as desired during the curing process. 

Green onions are seeing thrips populations slow down. Typically, thrips populations will decrease as we enter into Autumn and see these species move onto weedy hosts. 


Sanitation is an important component of an integrated disease management program. In small fruit and tree fruit alike, there are diseases that can over winter on infested fruit, foliage and branches. As the season winds down, it is still important to scout for diseases that may be present, identify the disease and have a plan of action to manage the disease. Finding and removing mummy fruit, which are dried and shriveled fruit that are typically full of fungal structures, will help to significantly reduce disease inoculum from the production area. Too, mowing and mulching or raking away the leaves from around the trees and bushes reduces the amount of viable inoculum that may be overwintering in foliage. Much progress can be made towards disease management with efforts made in the fall. Taking these steps, and committing to them long term, helps to break disease cycles and reduce the overall pathogen load over time. 

Fruit rots are being observed in apples, including white rot and bitter rot. Bitter rot is common in apples during warm, wet conditions. For more information, take a look at this OSU article on bitter rot in apple. Marsoninna blotch is also found on apples. 

The pawpaw crop in Ohio this season has been later and smaller than past years. Pawpaw is a niche crop that is gaining popularity with Ohio consumers and can be used as an ingredient in specialty craft beers, ice cream, and other value-added items. For more information on pawpaw production, check out this factsheet from Cornell University. Learn more about the pawpaw industry in Ohio by visiting the Ohio PawPaw Growers Association website.

Pawpaw fruit cluster. Photo by Clemson University. 


Upcoming Events

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

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

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference


OSU Extension Bi-Weekly Fruit & Vegetable Report – September 15th, 2023

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 below:

Farm Science Review 2023

The Farm Science Review (FSR) is one of the nation’s premier farm shows and one of OSU Extension’s largest, most far-reaching educational programs. The event will be held at the Molly Caren Agricultural Center near London, Ohio on September 19th – 21st. The OSU Extension Fruit & Vegetable Team will be hosting a tent all 3 days that will feature presentations from academic and industry speakers on a variety of topics, including nutrient management, entomophagy, integrated pest management, variety trial results, farm marketing, and more. The OSU Extension Fruits & Vegetables exhibit will be located near the gazebo near the Utzinger Garden (booth 385). We hope to see you there!

Check out the 2023 Farm Science Review Program for further information.

Speaker schedule for OSU Extension Fruits & Vegetables exhibit at FSR 2023. Note: There will also be a presentation by Dr. Marne Titchnell, Extension Wildlife Program Director for OSU,  on wildlife management in fruits & vegetables on Wednesday, September 20th from 1:30 – 2:00 PM.

Purple carrot-seed moth detection

The OSU Plant & Pest Diagnostic Clinic (PPDC) recently received an insect sample that was identified to be purple carrot-seed moth (Depressaria depressana), a known pest of crops in the Apiaceae family. This was the first report of purple carrot-seed moth found in Ohio, though it has been found in neighboring states. The insect feeds on the flower heads of crops like carrot, parsnip, dill, celery, parsley, and more, but it is yet unknown if it will be an economically important pest of these crops in Ohio. Check out the article from PPDC for more information.

Please report any suspected larvae/adults with pictures to entomology@osu.edu or ppdc@osu.edu.

Purple carrot seed moth larvae (top) and adult (bottom). Photo by Iowa State University Extension (top) and University of Wisconsin-Madison Department of Entomology (bottom). 

Crop updates



Downy mildew continues to wreak havoc in cucurbit plantings this time of year. As a refresher, here is a factsheet from Michigan State University on downy mildew mitigation. Powdery mildew pressure is reported to be increasing in southern Ohio. Striped cucumber beetles populations are declining in central/northeast Ohio and transitioning more towards higher numbers of corn rootworm beetles. Western corn rootworm, a look-alike of striped cucumber beetle, also feeds on cucurbits and can impact yield if heavy populations are present. Check out this article from Iowa State University for information on identifying different rootworm beetle pests. 

Virus symptoms are being observed in some melon plantings. There are various aphid-vectored potyviruses that affect cucurbits and they can be hard to differentiate from one another, though control practices are similar for all of them. The big 4 for cucurbit crops are cucumber mosaic virus, papaya ring spot virus, watermelon mosaic virus, and zucchini yellow mosaic virus. Like many crop diseases, management practices are preventative and include using resistant varieties or planting earlier to ensure harvest before viral symptoms appear towards the end of the season. Getting aphids under control may also minimize virus infection to some degree.

Cucumber mosaic virus – symptoms include yellowish-green “mosaic” mottling on foliage or fruit and crinkled leaves. Photo by Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org.

Papaya ringspot virus – symptoms include wrinkled leaves and discolored, bumpy fruit. Photo by Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org.


Watermelon mosaic virus – symptoms include wrinkled leaves and geometric patterns on fruit.  Photo by Dorina Pitorac, European Plant Protection Organization.

Zucchini yellow mosaic virus – symptoms include blistered, wrinkled leaves and fruit with discolored bumps. Photo by University of Massachusetts Extension.

Fruiting Vegetables

Late-season aphid feeding is being observed in some solanaceous crops. Honeydew is a sugary liquid secreted by aphids and other sap-sucking insects (whiteflies, spotted lanternfly, etc.). Honeydew accumulation on crop foliage or fruit can lead to growth of sooty mold, which is a term for various genera of fungi that colonize the sticky exudate. Sooty mold does not render vegetables inedible, however, and can be readily washed off. 

Honeydew from aphids (and other sap-suckers) on plant leaves is sticky to the touch and can be colonized by sooty mold. Photos by Kansas State University Entomology (top) and Joe Boggs, the Ohio State University Extension (bottom). 

Regular bouts of rainfall as we head into the fall are leading to increased incidence of Phytophthora infection in peppers (and cucurbits). While excess water is a problem for some vegetable growers in Ohio, some parts of western Ohio still remain abnormally dry, according to the U.S. Drought Monitor. Mites have been a problem in some areas, while thrips have taken a downturn. Keeping mites under control towards the end of the season can reduce the chance of heavy pressure next season by reducing the egg load/number of overwintering adults that will become next year’s mite infestations.


Tree fruits

Early varieties of apples are being harvested across the state. Brown marmorated stinkbug pressure is increasing. Bitter rot is starting to be observed in some orchards. Marssonina leaf blotch is also being seen in some organic orchards, where management can be difficult without the use of fungicides. Removal/destruction of leaves on the orchard floor in the fall can reduce overwintering sites for the pathogen. Black knot is being seen on some ornamental plum trees, so commercial plum and cherry growers should keep an eye out for black knot galls on their trees and promptly remove them if they see them.

Gall of black knot (Apiosporina morbosa), a fungal pathogen of plum, cherry, and other types of fruit trees. Photo by Joseph O Brien, USDA Forest Service, Bugwood.org.

Small Fruits

Preparing Brambles for Winter – Sanitation Practices for Disease Prevention
Melanie Ivey, State Fruit Pathologist and Fresh Produce Safety Specialist, The Ohio State University

Disease management of perennial fruit crops is a year-round endeavor. Many fungal pathogens survive the winter months in the soil or plant debris, infected canes or buds, or dead canes. As part of an integrated disease management program fall sanitation practices to reduce inoculum in the planting should be done.  Best sanitation practices include removing floricanes after harvest, removing diseased and dead canes, removing dead or systemically infected plants, and raking or chopping fallen leaves. Pruning debris should be destroyed by burning or placing in the trash or discarding it away from the planting. Diseased plant material should not be composted.  Pruning cuts should be sharp and clean to avoid unnecessary mechanical wounds.

The fall is also a good time to scout for and remove wild bramble populations that are near the production field. In addition to fall sanitation practices, some diseases require a dormant or delayed dormant fungicide application. For dormant or delayed dormant fungicide recommendations consult the Midwest Fruit Pest Management Guide (OSU Extension Bulletin 506).

The table below summarizes where the fungi for several common diseases of brambles in Ohio overwinter, the recommended fall sanitation practices for each disease, and whether a dormant or delayed dormant fungicide application is recommended.

Upcoming Events: 

September 19 – 21, Farm Science Review

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

September 30, Albany, OH OEFFA CSA Veggie Farm Tour

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

January 15 – 16, Columbus, OH, 2024 Ohio Produce Network

February 15 – 17, Newark, OH, 2024 Ohio Ecological Food and Farm Association (OEFFA) Conference

Impacts of Drought on Vegetable Production and Potential Solutions

Much-needed rain on Sunday has given agricultural producers some reprieve from the “flash-drought” that has been building across Ohio over the past few weeks. Ohio has seen abnormally-dry to moderate-drought conditions across much of the state, according to the U.S. Drought Monitor. The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES) has activated its Rapid Response Team to address the dry weather and provide extension resources for agricultural communities, including commercial vegetable producers. More information can be found at the OSU Early Drought Response webpage.

Periods of drought have plagued humanity since agriculture began. In modern vegetable production systems, dry conditions can lead to issues at multiple levels. This article will unpack the impacts of drought on vegetable production and discuss possible solutions.


Crop moisture stress

Crops vary widely in their water use efficiency (WUE), i.e. the amount of carbon produced per unit of water taken up by the plant. Many grain crops have been specifically bred for high WUE to maintain productivity in dryland systems. Vegetable crops, on the other hand, have comparatively low WUE and are typically irrigated via drip tape or center-pivot. Due to their higher water needs in “normal” seasons, many vegetable growers are already set up for irrigation and so may not be witnessing as severe crop moisture stress as field crop growers who rely on the rain.

Heat stress

In addition to the lack of rain, temperatures in northwest Ohio climbed into the high 80s near the end of May. High temps can threaten young plants in other ways apart from increased water demand. When crops are transplanted into black plastic mulch they can be stressed by heat radiating off the mulch surface. Young plants can also be burnt if any plant tissue is contacting the black plastic, which may be common if soil moisture levels are below wilting point. Transplanting into wet soil, overhead irrigation, or applying kaolin clay to plastic mulch surfaces to temporarily increase sunlight reflection can help keep temperatures around the plant cool and conducive to crop health.

Dry weather pests

Hot, dry weather in the spring can lead to earlier and increased activity in plant pests like thrips, aphids, and spider mites. These insects thrive in warm and dry conditions, which is why infestations in greenhouse environments are common. Insect feeding can reduce crop yield and quality and the pests can also vector viruses that affect vegetable plants.

Outbreaks of thrips, aphids, and spider mites can be managed in part by supporting natural enemies of the pests. These include ladybeetles (adult and larvae), lacewing larvae, and minute pirate bugs. Aphids are also preyed upon by damsel bugs, assassin bugs, aphid predatory midges and several predatory wasps. Species of predatory thrips and mites can also help keep pest thrip and spider mite populations in check. Find information on identifying natural enemies in this guide from OSU Extension and this educational video from Dr. Mary Gardiner at OSU.

Insecticide/miticide recommendations can be found in the 2023 Midwest Vegetable Production Guide. Avoid broad-spectrum products to conserve natural enemy and pollinator populations in the field. Read more on the topic in this article from Zsofia Szendrei at Michigan State University.


















Pests that prefer hot, dry conditions: aphids (top), thrips (middle), and spider mites (bottom). Photos by University of Illinois Extension (top), Ontario Ministry of Agriculture, Food and Rural Affairs (middle) and Mississippi State University Extension (bottom).

Weed control

Drought conditions also have implications for early-season weed control. With low moisture in the topsoil, weed emergence may be delayed and prolonged. Applying layby residual herbicides is important to keep weeds under control until canopy closure. Weeds that are heat/drought stressed also do not respond to postemergent spray applications as well as vigorous weeds. Plant leaves develop a thicker, waxier cuticle to minimize water loss which can also reduce herbicide absorption. Adjuvant usage may be needed to improve conditions for herbicide uptake. Weed growth and metabolism is also slowed, which reduces movement of systemic herbicides around the plant. Spraying in the morning can be advantageous for weed control, not only because of calm winds, but also because targeting plants at a time of day when they are the least heat stressed can improve performance of systemic herbicides. Read more on this topic in this recent article from Erin Burns and Christy Sprague at Michigan State University.

Wildlife damage

 Wildlife damage to crops can be worsened in hot, dry weather. Rodents and other vertebrates may increase feeding in vegetable fields when food and water is scarce elsewhere. Irrigation equipment may be damaged by wildlife (coyotes, mice, etc.) looking for a drink. Options for keeping away wildlife include netting, fencing, repellants, trapping, and other lethal/non-lethal deterrents. Resources include the Ohio DNR Nuisance Animal Control Manual and Wildlife Management Factsheets from the USDA/Michigan State University Extension.

Farm safety

Last but not least, the safety and well-being of agricultural workers is important to keep front of mind. Working in hot and dry conditions poses a risk of heat-related illnesses. Continuous hydration and proper attire can go a long way towards ensuring worker safety. Find more information on the major heat-related illnesses and their mitigation in this article from Penn State.

Dealing with drought-stressed crops and dusty fields can also take a toll on growers’ mental health. Ohio State University Extension offers resources to help handle farm stress. Farm worker/manager performance is dependent on good mental health, so be sure to take this aspect of your vegetable operation seriously.

To sum it up, hot and dry conditions impact multiple aspects of vegetable production. While the material here mainly addresses the consequences of a dry spring, drought can cause different issues depending on when in the growing season it occurs. OSU Extension is a resource to help vegetable growers through periods of drought by providing information and support. Please reach out to your county educator or a vegetable extension specialist to explore ways OSU Extension can help you make your vegetable operation more resilient to drought conditions.

Thank you to Ben Werling and Ben Phillips from Michigan State University Extension for observations and ideas that contributed to the writing of this article.

Chris Galbraith

Vegetable Extension Educator

Northwest Ohio
Ohio State University Extension
Office: 734-240-3178

Striped Cucumber Beetles Appearing Soon at a Field Near YOU!

Jim Jasinski (Extension), Ashley Leach (Entomology)

It’s been cool and wet in most of Ohio slowing most planting schedules but cucurbit planting is poised to hit it’s stride toward the end of May through mid-June. This means growers need to be on the lookout for the primary early season pest of pumpkin, squash, melons, cucumbers and zucchini, the striped cucumber beetle.

Striped cucumber beetle adult.

These adult beetles are overwintering now but will begin actively searching for cucurbit seedlings to feed on, sometimes inflicting severe enough damage to outright kill plants. Recall that while seedlings can survive and outgrow minor beetle damage, it is key to avoid severe damage to seedlings in order to prevent bacterial wilt transmission while the plants are most susceptible, typically prior to the 3-4 leaf stage. Bacterial wilt infected plants will become symptomatic once there is high demand to translocate water from the roots to the shoots, such as the time of fruit enlargement. No treatments are available to reduce bacterial wilt once a plant is infected.

Bacterial wilt infected plant in foreground, healthy plant in background.

Scouting newly emerged cucurbit plantings every few days is essential to determine if enough beetles or damage is occurring to warrant treatment. Action thresholds vary from 0.5 – 1 beetle per plant for cotyledon and 1st leaf stage seedlings to 1-2 beetles per plant for 3-4 leaf stage seedlings. Scout about 50 plants in both edge and interior areas throughout the field, flipping over leaves and especially looking under cotyledons to accurately determine beetle pressure and damage.

Severely damage cotyledon by striped cucumber beetle feeding.

Foliar insecticide recommendations for all cucurbit crops can be found in the Midwest Vegetable Production Guide (https://mwveguide.org/uploads/pdfs/Cucurbit-Crops.pdf).

To prepare for the arrival of striped cucumber beetles, consider reviewing a short but detailed video of several management options (beetles/plant thresholds, systemic seed treatment, use of transplants and in-furrow application) posted to the OSU IPM YouTube channel (https://youtu.be/RSzTT_gbma4).

A quick word about using insecticides to manage early season beetle populations. Based on your farm history with damage from this pest, field size, time of direct seeding or transplanting, you may not experience peak beetle pressure and can manage this pest by frequently scouting seedlings and treating if over threshold, the old fashioned IPM method!

If you purchased systemic insecticide coated seed (FarMore FI 400) which is very effective at controlling beetles, as evidenced by the pile of dead cucumber beetles on and near the treated plant, be aware that trace residues will accumulate in the pollen and nectar. If foraging honey bees, bumble bees, squash bees and other pollinators collect these food resources they may not be outright killed but more subtle sub-lethal effects on brood such as reduced feeding, fewer wax cells constructed, fewer eggs laid and other effects might occur. So, decisions about pesticide selection, pest severity, timing and non-target impacts should be considered before use.

Dead cucumber beetles at base of systemic insecticide treated plant. Courtesy of Celeste Welty.

If using FarMore FI 400 treated seed to raise transplants, do not treat them again with a systemic insecticide product during field setting as this will increase the residues found in pollen and nectar. If applying systemic products in-furrow, using the lowest labeled rate will still provide great beetle control for 2-3 weeks.

Mad about Maggots?

Have you visited your vegetable field lately and come back disappointed because you were met with wilted, drooping plants? You are not alone. Recently, we have had an uptick in reports of maggot damage in vegetable crops. The insect culprits in question are most likely either onion maggot, seedcorn maggot or cabbage maggot. These maggots are very similar, and even belong to the same fly genus, Delia. These cream-colored maggots are small (0.5-1.5 cm) and have between 3-5 generations per year. These fly species will overwinter as pupae in the soil and emerge as adult the following year to find suitable host plants. Maggot will feed on seedlings and either kill the plant before it can successfully mature or injure the plant, thus giving entry to soil pathogens (secondary infections). This past season, you may have noticed more damage from maggots than normal. And that’s not surprising; maggot damage is typically greater in cool, wet seasons and in fields with high organic soil types.

There are some differences between these species that may point to one being the cause over another. Onion maggots love alliums, and are most problematic in onion, garlic, and leek. Cabbage maggot has an affinity for brassica crops including cabbage, cauliflower, Brussel sprouts, and turnips. Seed corn maggots love just about everything and can be found in as many as 40 different plant hosts. Notable crop hosts for seed corn maggot include soybeans, corn, beans, peas, cucumber, melon, pepper, potato, and even onion. As a general rule, seedcorn maggots typically damage the seed, whereas onion/cabbage maggots often feed on seedling roots.

The bad news is that if you are facing maggot damage there is little you can do to “rescue” your planting. Your best bet is to wait it out and replant if possible. You can drench with Diazinon (Diazinon AG500), but this product won’t ultimately save you from the damage that has already been afflicted. If you decide to use this product, make sure you use enough water. Diazinon doesn’t move easily through the soil and is best applied with adequate water.

Avoid “chasing” adult flies. You may see adult flies (figure 1) in your field but using foliar insecticides to kill adult flies is not an effective option for any species. Keep in mind the damage is in the soil, so make sure you target your management decisions to strategies that will protect the below-ground tissues of the plant (I.e., seed treatments or in-furrow applications at planting/transplanting).

If you are dealing with maggot damage on your farm, consider some of the options below.

  1. Prevention is key. If you know you have a history of either seed corn maggot or onion maggot, make sure you take action by preventing an infestation before it starts.
    • Rotate your crop. Flies will show up when they know food is available. So do your best to confuse the flies by rotating your crops, especially alliums and brassicas. If you want to limit future infestations, consider planting a non-host crop to decrease the likelihood of subsequent maggot problems. If you are rotating your crop to a non-host, make sure you rogue out any volunteers from the previous year. (Maggots love volunteers!)
    • Use a seed treatment (Table 1). Insecticide treated seed is one of the most effective tactics to manage maggot populations. A number of efficacious products are available including thiamethoxam+ spinosad (FarMore FI500), cyromazine (TRIGARD), and clothianidin and imidacloprid (SEPRESTO) for many vegetable seeds (table 1). Rotate products between years so you are not exposing multiple generations to the same active ingredient. For example, if you are using FarMore in year 1, rotate to a different seed treatment like Trigard or Sepresto in year 2. WHY DOES THIS MATTER? Reports from the Northeast and MidAtlantic suggest that some maggot populations may become resistant to these seed treatments.
      Table 1: seed treatment options to manage  maggot infestations in vegetables. Please note that efficacy of these products may differ based on maggot infestation and/or soil type.
      Product OMRI listed? Active ingredient Relative control of maggot IRAC codes
      FarMore FI500 No. thiamethoxam+ spinosad Excellent. 4A, 5
      Trigard OMC No. cyromazine Excellent. 17
      Sepresto 75 WS No. clothianidin+ imidacloprid Good. 4A, 4A
      Regard SC Yes. spinosad Excellent/Good. 5
  2. Exclude flies from the crop. One viable management approach is to keep female flies from finding your crop. You can isolate your crop either in space (row cover) or time (degree day modeling).
    • Consider using row covering over your susceptible crops to stop adult oviposition (egg-laying). Multiple studies have found that this is a highly effective method at limiting damage.
    • Avoid maggot damage altogether by planting later in the season to bypass peak infestation. Maggots have predictable phenological patterns, and you can use degree day models to accurately predict times in the season when maggot risk is high. The first peak of seedcorn maggot occurs earliest in the season when 200 degree days has been accumulated, followed by cabbage maggot (250 degree days) and then onion maggot (250-300 degree days).
  3. Monitor, monitor, monitor. While there is little you can do to manage maggot infestations within the immediate growing season, it’s important to identify problem areas so you can plan accordingly for the following year.
    • The best way to tell if you have Delia maggots on your farm is to scout early and often. Fields with poor plant emergence or wilted seedlings (figure 1, video) should be inspected for maggot damage. Make sure you cull any infested plants.

Insect Management & Vegetable IPM Survey – Last Call

Researchers at Purdue University and the College of Wooster are requesting responses from vegetable growers in the Great Lakes and Mid-Atlantic regions to learn more about their insect pest management practices to help direct pest management research and extension programs in specialty crop production!

QR code to participate in survey

Alert – Corn Earworm Moth Numbers Running Very High!

On the heels of the VegNet blog article posted a few days ago (https://u.osu.edu/vegnetnews/2022/08/13/corn-earworm-flight-numbers-spike/), corn earworm flights continue to be very high in southwest Ohio. In the past 10 days, over 1,000 moths have been trapped at the research station in South Charleston, including 424 moths caught from Friday (12th) through Monday (15th).

This pile is what 424 CEW moths looks like.

The Hartstack trap (large metal mesh) used at the research station is placed near fresh silking sweet corn which is very attractive to CEW moths and known to catch more moths than a Heliothis trap (white plastic mesh). Be sure to use the CEW management chart, which is based on the Heliothis trap, when making management decisions. Traps placed away from fresh silking corn will not catch as many moths.

These large moth flights have yet to be recorded in the northern county tier of traps in the network (https://u.osu.edu/jasinski.4/pestvisualization/#linke). Growers who are running Hartstack or Heliothis type traps to manage their insecticide spray intervals are advised to check their traps every few days for the next few weeks.

CEW flights in monitoring network.

Corn Earworm Flight Numbers Spike

Clark County has reported a massive spike in corn earworm (CEW) this week.

386 CEW moths caught during past week.

Other trapping locations have not reported an increase in activity yet (https://u.osu.edu/jasinski.4/pestvisualization/#linke). This annual caterpillar pest of sweet corn and tomato should have growers paying special attention to these crops for infestation, especially during the latter part of the season. Flights of CEW typically increase through the summer as the moth migrates into Ohio from southern states such as Louisiana, Texas and Mississippi. The caterpillar stage is known to attack silking corn and tomato fruit, especially when other susceptible hosts are not abundant.

CEW, aka tomato fruitworm, feeding on tomato.

Moths prefer to lay eggs on fresh sweetcorn silk and can hatch and enter the ear tip as quickly as two days under ideal weather conditions, where they are no longer susceptible to insecticide treatments. Treatments for this pest should be made based on number of moths per day and daily temperature threshold of 80F. Use the chart below to determine the recommended number of days between insecticide application to protect sweet corn as it enters silking. Insecticide options can be found in the Midwest Vegetable Production Guide, remember to rotate insecticide classes to avoid resistance (https://mwveguide.org).

CEW spray interval chart.

Want to learn more about monitoring for CEW? Check out this original video that reviews how to set up a trap to monitor for CEW (https://www.youtube.com/watch?v=W6b7OtUOo8Y&list=PL0HRPaZDLHyG53DPisl9iGTezcx815u-q&index=8).

There is also an updated version of how to monitor for several key moths in sweet corn on the OSU IPM YouTube channel https://youtu.be/X1jvQxx_fpc

What’s that on my cucurbit?

As noted by Sally Miller last week, bacterial wilt and yellow vine decline are being found in cucurbit fields across the state. There are two primary insects responsible for these outbreaks, the Striped cucumber beetle (Acalymma vittatum) and squash bug (Anasa tristis). I was just scouting some of my pumpkins this past week and counted 20 beetles in one flower! But sometimes looks can be deceiving as we can encounter as many as 4 different types of beetles in our cucurbit fields. It’s important to know what’s in your cucurbit since it could be the difference between making an insecticide application (or not). Below, I have included an image of different beetle species you may encounter in your cucurbit fields. As a reminder, we generally want to make an insecticide application when the striped cucumber beetle density exceeds 1 beetle/plant in a field. If you want information about specific products, check out my former post here.

Squash bugs are arguably easier to scout for since there aren’t many other insects that resemble them. However, we need to keep track of different squash bug life stages (shown below). Squash bug eggs are fairly diagnostic with a bright amber coloring. They are typically found along the midribs on the undersides of leaves. Those egg masses eventually give rise to nymphs which are powdery blue. Adults have a flattened appearance and are typically brown with alternating white and orange spots along their abdomen. Insecticide applications are warranted when squash bugs exceed a cumulative threshold of 1 egg mass, nymph or adult bug/ plant in a field.