This edition of the OSU Extension Fruit & Vegetable Report was written using field observations and expertise from the following OSU Extension staff: Mark Badertscher, Thomas Becker, Chris Galbraith, Melanie Ivey, Carri Jagger, Matt Kleinhenz, Ashley Leach, Gigi Neal, Francesca Rotondo, Sabrina Schirtzinger, Ryan Slaughter
Vegetables
With periods of hot, intense weather so far this season, there have been reports of heat stress in transplants and in hoophouse crops. It is during times like these that managing temperatures in high tunnels becomes of great importance. It can pay to be proactive and utilize strategies for cooling your hoophouse before symptoms appear in your crop. Consider the specific crop, its growth stage, whether it is fruiting vs. non-fruiting, its temperature tolerances, and other factors when determining whether to apply shade cloth, vent the tunnel, or take other measures. Dr. Matt Kleinhenz of the OSU Vegetable Production Systems lab recently gave a lecture on the topic of high tunnel temperature management – check it out at the following link:https://www.youtube.com/watch?v=9dZyPo7Itv4
Squash bugs and squash vine borer are out and feeding. Squash bugs do not seem to be much of an issue yet in some areas. Striped cucumber beetle populations are high and reaching threshold in watermelons and other crops. Some organic growers have been using kaolin clay to prevent cucumber beetle feeding. Kaolin clay can also be applied to black plastic mulch during hot spells in order to cool down the microclimate and reduce heat stress in transplants. Cucumber downy mildew has been found in Ohio. Flea beetle defoliation is being seen in cole crops. Diamondback moth larvae, imported cabbageworm, and other caterpillars are out and feeding. Heat blistering on tomato stem tissue was reported during the recent period of extreme heat. There is very high thrips pressure in some pepper plantings. Japanese beetle, slug, and vertebrate wildlife damage is also being reported in various vegetable crops.
Flea beetles can be voracious pests of cole crops, leaving shot hole patterns in leaves. Photo by Chris Galbraith, OSU Extension.
Fruit
Many abiotic disorders related to the unusual weather have been coming into the diagnostic lab this season. Wooly apple aphids have begun moving out on tender new growth. Diazinon, one of the chief crop protection products for this pest, is no longer being manufactured so control is more of a struggle. Oriental fruit moth populations are peaking. Bacterial leaf spot is being reported in peach. Powdery mildew is also being observed in apples, grapes, and peach.
Bacterial leaf spot can be a severe disease of stone fruits. Photo by U. Mazzucchi, Università di Bologna, Bugwood.org.
Blueberries have been hitting their peak in harvest, around two weeks ahead of normal this year. The strawberry season was reported to be poor this year – berries did not size up well and plants were not as vigorous this season on some farms.
This edition of the OSU Extension Fruit & Vegetable Report was created using field observations and expertise from the following OSU Extension staff: Mark Badertscher, Frank Becker, Thomas Becker, Ed Brown, Chris Galbraith, Melanie Ivey, Matt Kleinhenz, Ashley Leach, Logan Minter, Gigi Neal, Sabrina Schirtzinger, Ryan Slaughter
Vegetables
A common trend this spring is the delayed planting in many parts of the state due to consistent rainfall that held up field work. Transplants that have been held onto for too long may become rootbound and stressed, exacerbating transplant shock and generally delaying growth and development. With that said, conditions have been dry in other parts of the state such as SE Ohio and could benefit from more rain at this point.
Cucumber beetles are out feeding and bacterial wilt was reported in southern Ohio. Cucumber beetles thresholds are lower for younger plants because of the outsized risk of lethal infection. Seed treatments have been the go-to solution and they seem to be handling pressure well so far this season where they were used. Squash bugs have also emerged and are active.
Bacterial wilt of cucurbits. Photo by Jim Jasinski, OSU Extension, Bugwood.org
Flea beetles are feeding in cole crops. Imported cabbageworm and cabbage maggot feeding is severe in some brassica plantings. Heavy imported cabbageworm pressure has been observed in western Ohio.
Severely stunted growth can be an above-ground symptom of cabbage maggot root feeding. Photo by Chris Galbraith, OSU Extension.
Severe Colorado potato beetle defoliation is being seen in eggplant and potatoes. Some growers have found extended protection using imidacloprid when planting seed pieces. Spinosad is another option in the arsenal, with the added benefit of being organic compliant.
Foliar diseases are being detected in high tunnel tomatoes. Many of these pathogens present on lower foliage first. At the time of fruit set, the lower ⅓ of leaves on tomato plants are generally not particularly productive from a photosynthesis standpoint, and therefore can be pruned to improve airflow between plants. Whitefly and aphid presence has been noted in peppers. Thrip pressure is heavy in onions in some areas.
As is the case every year, spray drift is being observed in vegetables. In some instances, symptoms resembling drift damage may occur on your vegetable crops when there is no obvious source of pesticides nearby. Drift particles may be moved surprisingly far by temperature inversions or other weather conditions. Other times, it may be an issue with herbicide residual activity in the soil.
One question from a community member: Is produce still safe to eat in cases where there is crop damage from pesticide drift? As is the case with most food safety questions – when in doubt, it’s best not to take the risk. There is uncertainty around how long it takes before residue levels are at or below the tolerance levels for situations in which a chemical is not registered for a specific crop. It is better to be on the side of caution when it comes to pesticides and produce safety.
Fruit
Fire blight incidence is high in some apple orchards. Apple scab is also being observed this year, with most infection occurring on fruit rather than foliage. Powdery mildew is being reported. Codling moth flights have been strong this season which is leaving growers with weekly sprays. Dogwood borer flights are particularly strong, and we do not have clear peaks this season. Some rosy and green apple aphids, as well as white apple leafhoppers, are being observed in orchards.
Bacterial leaf spot is being reported on peaches. Peach leaf curl incidence is also high so far this season. Peach X-disease was recently confirmed by the OSU diagnostic lab. There is oriental fruit moth activity in some peach orchards but seems to be well controlled in most cases.
Foliar symptoms of peach leaf curl. Photo source: Nancy Gregory, University of Delaware, Bugwood.org
There have been calls about thrips and sap beetles in strawberries.
Similar to vegetables, herbicide drift damage is popping up in vineyards and other fruit. For commercial growers who have experienced significant losses, reach out to ODA to report drift damage. For those wishing to pursue legal action – as soon as damage is observed, store damaged tissue in the freezer for preservation so that it can be tested at a later date.
The OSU Extension Fruit & Vegetable Report is written and published collectively by OSU Extension staff across the state.
Vegetables
Onion plants are off to a quick start this spring. As the plants quickly add leaves, this provides ample opportunity for onion thrips to get started. Scouting for onion thrips is incredibly important early in the season as they become increasingly more difficult to manage as the season progresses and the onion plants become larger and more heavily foliated. Scouting for thrips involves carefully pulling apart onion leaves near the neck and examining down into the crotch of the leaves. On a sunny day, thrips will react to the sudden exposure of sunlight by moving downward, deeper into the leaf collar. As you evaluate management decisions, also be aware that heavy rains may provide assistance in management of onion thrips as the rain washes the thrips out of the leaves or drowns the insect.
Photo by Frank Becker, OSU Extension.
Colorado potato beetles are emerging and becoming active in potato plantings. The adults are very difficult to control with pesticide applications. Control is more effective when applied to newly hatched larvae. Please reference the Midwest Vegetable Production Guide to find effective products for management of the Colorado Potato Beetle.
Colorado potato beetle larva feeding on potato foliage. Photo by Chris Galbraith, OSU Extension.
Squash and cucumber continue to be seeded. Striped cucumber beetles are out. As an important reminder, early season control of cucumber beetle is critically important in preventing bacterial wilt in your cucurbit plantings. The threshold for beetles while plants are in the cotyledon stage is 0.5 beetles per plant. The threshold for beetles at the 3-4 leaf stage is 1-2 beetles per plant, and for plants with 4 or more leaves, 3-5 beetles per plant. Scouting during the morning or evening will give you the best results, as beetles are often difficult to find during the heat of the day. Recent chewing and feeding damage can also be indicative of beetle activity. This can be differentiated from “old” feeding damage as the older damage will look scabbed over, but the recent feeding will appear as a “wet” wound.
Cabbage maggot, caterpillar, and swede midge damage is being observed in cole crops. Reports of some early season flea beetle activity have led to some growers already making applications to limit damage to young cole crops. Flea beetle feeding can be scouted for by looking for “shot hole” style feeding patterns on the foliage of the plants. Early season feeding, especially on young transplants can significantly stunt the plants, and in some cases when feeding is severe enough, seedling death can occur.
High tunnel tomatoes are fruiting and field tomatoes are being planted where growers can get into the fields. 2-4,D drift damage has been observed in some high tunnels. Powdery mildew and thrips are the main pest of concern in greenhouse tomatoes at this point in the season.
Early blight and powdery mildew have both been found in high tunnel tomatoes. Powdery mildew, as the name describes looks like powdered sugar on the upper leaf surface. These symptoms can develop at any level of the plant. Early blight, or Alternaria, has an alternating ring/bullseye like pattern, often with a yellow halo around the lesion. Early blight is most often first found on the older foliage near the bottom of the plant. Please scout your high tunnel tomatoes frequently and thoroughly, especially early season to catch early season disease presence and hopefully prevent major impacts throughout the season. Please read fungicide labels carefully to make sure that the crop and disease are both listed on the label. Remember, the label is the law.
Recently planted sweet corn is beginning to emerge. Slug damage is being observed, although not severe at this point. Now is also an important time to be checking sweet corn for black cutworm. Cutworms damage the pants by cutting the plant off at or slightly below the soil line, significantly stunting the plant or causing plant death. If infestation levels are high enough, stand loss can occur to the point of necessitating a replant.
Fruit
With the mild winter, fruit, vegetable, and agronomic crops alike are getting a quick start in Ohio this year! It seems the pathogens got the memo as well as educators and specialists around the state are reporting an early onset of several diseases on fruit. One disease that we are seeing in orchards this spring is apple powdery mildew.
Powdery mildews are among one of the more recognizable diseases in our specialty crops and can have a significant impact. Some folks are probably familiar with the cucurbit powdery mildew that we find on the cucumbers, zucchini, and other cucurbit crops in our fields in gardens. Powdery mildews are host specific, so the powdery that we observe on apple trees will not lead to powdery mildew infections in our cucurbit crops. They are different species. Usually, we see cucurbit powdery mildew as we get further into summer, around July. That particular pathogen does not overwinter in Ohio and has to be blown in by the wind from areas where it can overwinter.
Apple powdery mildew is quite different, caused by the species Podosphaera leucotricha. Apple powdery mildew can overwinter in fruit buds that were infected in the previous season. Another interesting thing about powdery mildew is that while it does need a higher relative humidity, it does not require free water for development. Many of our other diseases do have that requirement. So, even in drier years, powdery mildew can still pose a challenge.
Powdery mildew is one of those diseases where when we scout, we can observe both the signs and symptoms of the disease. In other words, we can see both the physical evidence of the powdery (Sign: the white fungal growth) as well as the plants response to the infection (Symptom: stunted, crinkled leaves). The first thing you will likely see in spring is the white fuzzy or waxy appearance to the leaves. As the disease persists, leaves will become stunted, crinkled, and brittle. As the season goes on, the disease can spread to the twigs, stunting their growth, and potentially leading to dieback issues. In severe cases, symptoms can show up on fruit resulting in russetted apples.
Photos by Thomas Becker, OSU Extension.
Apple powdery mildew can be managed with some cultural integrated pest management tactics. One tactic is to plant varieties that are less susceptible or potentially resistant to powdery mildew. Another tactic is to plant and manage your trees to allow for good air movement and light penetration. This can lower the relative humidity around the trees and make it more difficult for the pathogen to get established. Chemical controls are also an option. If powdery is a persistent problem in your orchard, it may require the development of a good fungicide program to get adequate control. Contact your county extension educator, one of our state specialists, or reference the Midwest Fruit Pest Management Guide for current fungicide recommendations.
Apples have progressed quickly in their development. Codling moth trap catches are high across the state. Insecticides to control first generation codling moth should be on to slow the second generation. Wooly Apple Aphids are on the move in the trees, as they move from the roots to the limbs. San Jose Scale is present as well and male flight has been observed in southern Ohio. Plum curculio damage present (petal fall applications are best to control infestations). Pear psylla adults active.
Lacewing eggs hanging from branch. Lacewings are beneficial insects that feeds on aphids and other fruit & vegetable pests. Photo by Frank Becker, OSU Extension.
Strawberries are ripening and some varieties are in harvest. Main pests at this point are slugs, spittlebugs and birds. Phytophthora leather rot and sun scald being observed in fruit. Brambles are blooming, blueberries setting fruit.
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
Vegetables
Cucurbits
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.
Tomatoes/Peppers
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.
Fruit
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. 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!
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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.
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.
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:
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.
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
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.
Onions
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.
Fruit
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.
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!
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.
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
Vegetables
Cucurbits
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.
Fruit
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.
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 below:
Spotted Lanternfly
Thomas Becker, Lorain County Extension Educator, OSU Extension
Quarantine map of spotted lanternfly (top) and adult spotted lanternfly (bottom). Images by Ohio Department of Agriculture (top) and Thomas Becker, OSU Extension (bottom).
ANR educators from across the state have been busy over the recent weeks tracking infestations of spotted lanternfly. At this point in the year, we are finding mostly adult spotted lanternfly with a few 4th instar nymphs still lingering. The current primary host plants for spotted lanternfly are tree of heaven and wild grapevine. They have a wide range of hosts, but as Ohio State specialty crop entomologist Dr. Ashley Leach put it, tree of heaven and wild grapevine are “gateway hosts”. While the 4th instar nymphs and adults are quite sizable and more showy, making them a bit easier to spot, they can be detected earlier in the year by locating their egg masses and watching for the 1st-3rd instar nymphs. The egg masses can be particularly difficult to find, as they can camouflage rather well with the surface they are attached to, especially if that surface is the side of a tree. The 1st-3rd instar nymphs are black with white spots. The 1st instars are very small, only about ¼ of an inch. The 2nd and 3rd instars look about the same as the 1st, but they get larger as they progress through their development. The 4th instars are about ½ an inch in length and are mostly red with some black and they maintain their white spots. The adults are about 1 inch in length and about 0.5 inch wide. Their front set of wings is tan with black spots and their hind wings are red and white with black spots. They have their wings folded back most of the time, so your best chance at seeing the red hind wings is when they are in flight. The spotted lanternfly is not a strong flier. They have more of a gliding flight pattern, climbing up to someplace high and then launching themselves to glide to a new location.
Spotted lanternfly egg mass (top), early instar nymph (middle), and 4th instar nymph (bottom). Photos by Thomas Becker, OSU Extension.
The main concern with the presence of spotted lanternfly is their anticipated movement into some of our fruit crops, especially grapes. So far, many infestations are being found in tree of heaven and wild grape vines near railroads. Spotted lanternflies really aren’t a fly at all, they are a planthopper in the order Hemiptera. They have a piercing, sucking mouth part called a proboscis that they use to feed on the sap of their host plants. With high enough pressure from spotted lanternfly, plants can be weakened which can result in a decline in the overall health of the plant and could potentially lead to some dieback issues. They will also excrete honeydew which results in sooty mold. Since they can feed in such large numbers at times, the extent of the sooty mold can be impressive. The honeydew can also attract other unwanted insects that feed on the sugars found in the honeydew.
Group of spotted lanternfly adults. Photo by Thomas Becker, OSU Extension.
We ask that producers and homeowners alike keep an eye out for this pest and report your suspected findings. If you are able, collect the insect in a bag or jar and put it in the freezer or add a paper towel soaked with some rubbing alcohol to the container that you captured it in. If you are unable to capture the insect, try your best to get a clear picture of it for reporting purposes and get a nearby address or GPS coordinates of the site where you found the insect. You can then make a report using the online reporting system on the ODA website: Spotted Lanternfly (SLF) | Ohio Department of Agriculture
If you have questions, you can also reach out to your county extension’s Agriculture and Natural Resource educator. Here are some links with more information on spotted lanternfly:
Rhizoctonia fungi have recently been implicated in transplant loss of cauliflower in Highland county. This soil pathogen infects the surface of stem tissue at or below the soil line causing the appearance of the stem to rot off and the remainder of the plant to wither. This same pathogen is also responsible for damping off in direct-seeded plantings. No curative treatments are available. Preplant fungicide seed treatments and not planting transplants too deep are preventative measures. Wet and warm soil conditions exacerbate the issue.
Wirestem (Rhizoctonia) symptoms in cauliflower transplants – rotting stem tissue below the soil (left) and withering/decline of the plant (right). Photos by Logan Minter, OSU Extension.
Cucurbits
Squash vine borer population numbers have dropped as the single generation nears its end. Damage from caterpillars earlier in the season can still be observed in the form of boring/feeding damage in squash and pumpkin fruit. Squash bug pressure remains high in northern Ohio but has still been manageable with insecticides. Whitefly populations have been increasing recently in cucurbits and solanaceous crops. Leafhoppers may be being moved up into Ohio with recent weather systems and hopper burn is being observed on some crops. Phytophthora is still being observed in some fields, with lesions observed on mature watermelon fruit.
Squash vine borer larvae damage on pumpkin fruit. Photo by Chris Galbraith, OSU Extension.
Fruiting Vegetables
Processing tomato harvest continues in NW Ohio. Copious amounts of foliage in high tunnel tomatoes have been leading to a higher prevalence of leaf diseases.
Brown marmorated stinkbug and harlequin bug trap catches have been picking up. These insects, along with tarnished plant bugs, spotted lanternfly, squash bugs and other similar pests, are of the order Hemiptera and considered “true bugs”. These insects have piercing-sucking mouthparts that leave cosmetic defects on fruit in the form of small, dark feeding wounds surrounded by light, colored blotches. On tomatoes, feeding can also introduce fruit-rot pathogens or cause fruit tissue below the skin to take on a corky texture that reduces quality. For more information and images, check out this article from the Buckeye Yard & Garden Hotline. Migration of brown marmorated stinkbug into Ohio usually peaks around late September, bringing higher populations and risk of feeding.
Thrip and aphids populations have decreased slightly in the last few weeks, while mite numbers have gone up due to some hot, dry days.
Brown marmorated stink bug body and mouthparts. Photos by Patrick R. Marquez, USDA APHIS PPQ, Bugwood.org.
Symptoms of stink bug feeding on tomato fruit. Photo by Joe Boggs, OSU Extension.
Sweet Corn
Corn earworm pressure is up slightly in a few counties in northwest Ohio as a weather system from the south pushed corn earworm populations up into the region. European corn borer, a non-migratory insect, is still showing low trap counts throughout Ohio. Western bean cutworm trap counts have dropped off as the single generation has passed its peak. Keep up to date on statewide sweet corn moth trap counts through the C.O.R.N newsletter put out by the OSU agronomy team. The insect tracker on the insectforecast website can also help you visualize and plan for pest migrations into Ohio.
Fruits
Peach harvest is wrapping up for the season. Grape cane borer has been reported recently. With the loss of Lorsban (chlorpyrifos) in specialty crop production, there are few options for control of the pest. Disposing of pruning brush from vineyards can help to decrease sites that harbor grape cane borer.
On-Farm Research on the use of Entomopathogenic Nematodes as a biological control of Spotted Wing Drosophila
Dr. Gary Gao, Professor and Small Fruit Specialist, CFAES South Centers, The Ohio State University
Steinernema feltiae (SF) is an entomopathogenic nematode (EPN). It has been shown to significantly reduce adult spotted wing drosophila (SWD) emergence at the pupal and infested fruit life stage, as discussed in a poster presentation entitled “CAN NEMATODES AID IN SPOTTED WING DROSOPHILA (DROSOPHILA SUZUKII) CONTROL?” by Emilie Cole, Jacqueline Perkins, Rufus Isaacs, and Marisol Quintanilla. Steinernema feltiae (SF) treated pupae had significantly less adult emergence compared to the control.
As a part of the USDA-NIFA funded project, Dr. Gary Gao and his research assistant Ryan Slaughter conducted an on-farm EPN study at the largest blueberry farm in Lexington, Ohio. We sprayed Steinernema feltiae on the ground beneath the blueberry bushes weekly at the rate of 1 billion per acre on July 14th, 21st and 28th, 2023. Three bushes of the control and treated blocks were netted with insect netting to prevent cross contamination from neighboring plots. There were three replications. The number of SWD larvae in fruits using the saltwater test and the number of SWD adults in traps baited with apple cider vinegar and a drop of unscented dish soap were counted and recorded weekly on July 21st, 28th and August 3, 2023. Steinernema feltiae products come in pouches of 250 million. Four pouches (1 billion) are needed per acre.
Mixing Steinernema feltiae (SF) with water. Photo by Gary Gao, The Ohio State University.
Spraying Steinernema feltiae (SF) onto the ground beneath the blueberry canopies. Photo by Gary Gao, The Ohio State University.
SWD traps baited with apple cider vineyard and a drop of unscented soap. Photo by Gary Gao, The Ohio State University.
We are still figuring out the optimal timing, method, and rate of application. SWD is quite hard to control due to its short lifespan and multiple generations per year. In blueberry plantings, insecticidal sprays are very difficult to apply without knocking a lot of fruits off. A soil drench or spray with Steinernema feltiae may be one of the tools in the toolbox. We are hoping that a ground based robotic sprayer or drip irrigation can be viable methods of EPN application.
Project Information: RESTOCKING THE IPM TOOLBOX TO MEET INSECT MANAGEMENT CHALLENGES IN HIGHBUSH BLUEBERRY – National Institute of Food and Agriculture CPPM program (Grant No.2020-70006-33015 and Project Number: MICL05122)
Using Laser as a Bird Deterrent in Fruit Plantings
Dr. Gary Gao, Professor and Small Fruit Specialist, CFAES South Centers, The Ohio State University
Laser or laser scarecrows are becoming more and more widely used as a way to deter birds in fruit or vegetable plantings, fish ponds, and commercial buildings. Dr. Gary Gao saw a commercial model being displayed at the trade show of 2023 National Association of County Agricultural Agents annual meeting in Des Moines, Iowa.
AVIX MARK II, a laser bird deterrent produced by Bird Control Group. The company’s website is https://birdcontrolgroup.com/. Photo by Dr. Gary Gao, the Ohio State University.
AVIX Mark II can project a strong green laser beam and can be powered by solar panels or connected to a power outlet. There are a lot of testimonials by people from many different counties. The unit looks quite impressive. However, I do not have any data of my own to validate it. I would love to install a unit at our research center to see how effective it is. I was told that one unit can protect 20+ acres when mounted, installed, and used properly. It is important to use it in conjunction with other methods.
Dr. Gary Gao and Ryan Slaughter have tested a less powerful unit at CFAES South Centers. Our results have not been consistent. There are many reasons for this. One is that our unit may not be strong enough – our green laser beam may not be visible enough during the daytime for birds to see it as a threat. The second reason is that our unit may be shutting off at different times. Third, one unit may not be enough for full control. Two units may need to be installed in different parts of the farm to minimize unprotected space. Fourth, our units may need to be kept on in the evening to prevent birds from roosting at night. There may be other reasons as well – birds are very smart. After a while, the birds may get used to the green laser beam. Distress calls and other bird deterrent methods may need to be used as well to keep birds guessing.
More research is definitely needed to develop a more effective and economical way to reduce bird depredation. Lasers may play an important role in this. What we do know is that something has to be done to help growers!
The OSU Extension Fruit & Vegetable Report is written/published collectively by OSU Extension staff across the state.
Tillage Options for Annual Vegetables
Different kinds of tillage equipment vary widely in their level of soil disturbance. Some tools work the ground to a fine tilth for planting, while others cause minimal disturbance or target only the area where the crop will be planted. Certain vegetable crops succeed better with certain tillage types than others. The following will provide a brief rundown on several common tillage systems and their respective benefits and drawbacks.
Conventional tillageconsists of a primary tillage event to turn over the soil and provide a basis for further secondary tillage that is used to further chop and bury vegetation/residues and prepare the seed bed. A moldboard plow is one of the most common types of primary tillage, inverting the topsoil and fully burying surface vegetation. A chisel plow can also be used for primary (as well as secondary) tillage and involves fracturing the subsoil using shanks tipped with chisel points in a way that does not turn over the topsoil. Secondary tillage implements include a disc harrow, which uses steel discs to slice up soil clumps, weeds, and residue. Newer high-speed discs perform better at faster operating speeds compared to traditional types.
Tillage equipment uses a variety of tools to fracture and mix the soil as well as chop and bury residues. Top to bottom – chisel plow, vertical tillage implement, high speed disc, and strip till unit. Photos by Chris Galbraith, OSU Extension.
Conservation tillage refers to tillage systems that create considerably less disturbance, leaving > 30% of the soil surface covered with residues. The advantage is reduced erosion, increased organic matter, and improved soil structure and quality. Various conservation tillage practices include:
No-Till is a very common production system where the soil is not disturbed at all by tillage operations and crops are planted into the previous year’s residues. The advantages of eliminating tillage are well-established – no-till maintains soil structure, conserves organic matter, retains moisture, and prevents runoff. The potential downsides are also well known and include greater difficulties in accessing the field for planting during wet springs, delayed soil warming early in the season, and greater reliance on chemical weed control. Large-seeded vegetables like sweet corn or pumpkins are more typically grown in no-till production.
Vertical Tillage is a shallow form of tillage designed to work the soil minimally while leaving residues on the surface for ground cover benefits. This tool helps incorporate soil amendments or chop up residues to more manageable sizes while side-stepping the more disruptive effects of conventional tillage. Vertical tillage equipment consists of fluted coulters, chopper reels, rolling baskets, and other features that open up the ground for warming and speeds decomposition by chopping/sizing residues, all in a way that has less negative repercussions than the heavier forms of tillage achieved by a plow or disc harrow.
Strip Tillage is the method of tilling only in strips where the crop will be planted, leaving soils undisturbed in between the strips. A typical row unit will include a coulter to slice through residue, followed by a row cleaner to clear the way for shanks, wavy discs, conditioners, and other attachments that help create a finely tilled strip. This method offers the best of both worlds by preparing a worked area that warms quicker than the inter-row zones while also retaining cover on top of most of the soil. Row units can further be set up to apply fertilizer or a fumigant to the strip during the same pass. Vegetables commonly grown in strip-tillage systems include sweet corn, squash, carrots, potatoes, and more.
Ridge Tillage is similar to strip tillage except that strips are formed as raised ridges to promote better drainage and aeration. Ridge tillage tends to be less common than strip tillage, particularly in vegetable production.
Cucurbit downy mildew symptoms on upper leaf surface (top image) and lower leaf surface (bottom image) of cucumber. Photo by Frank Becker, OSU Extension.
Fruiting Vegetables
Harvest of tomatoes, peppers, eggplant, and okra are all well underway. Verticillium wilt, Pythium fruit rot, and Phytophthora capsicihave been causing problems in some fields. Preventative practices for managing these pathogens by promoting proper drainage and preventing spread from infected to non-infected fields can help in reducing disease severity.
Pythium colonizing pepper fruit. Pythium appears as white, “cottony” fungal growth on fruit while Phytophthora spores on fruit more resemble powdered sugar. Photo by Chris Galbraith, OSU Extension.
Sweet Corn
Western bean cutworm catches in NW Ohio have decreased as of late, with high numbers still being reported in NE Ohio. Corn earworm and European corn borer catches remain low. Check out the most recent OSU C.O.R.N newsletter for most recent trap counts. Japanese beetles remain a pest on sweet corn, as well as other crops. Insecticide options include Assail (acetamiprid), Baythroid (beta-cyfluthrin), Warrior II (lambda-cyhalothrin) and other products. See this article from Iowa State University on the biology of this pest and spray thresholds.
Japanese beetles feeding on corn silks. Photo by Frank Becker, OSU Extension.
Fruits
Elderberry Fruits “Disappearing” from the Cluster (Cymes).
Dr. Gary Gao, Professor and Small Fruit Specialist, OSU South Centers
Ed Brown, the Agricultural and Natural Resources Educator with OSU Extension in Athens County, reached out to Gary Gao for answers on a question from a grower about fruits “disappearing” from the clusters or cymes of elderberries. There are several possible reasons for this phenomenon. The most common reason is bird feeding. As elderberry fruits turn color, birds typically start eating them. These little fruits are the perfect size for a lot of birds. Netting is the most effective way to keep birds out of the planting. It is important to put the netting on before fruits turn color.
Elderberry bushes with ripening fruits under bird netting. Photo by Gary Gao, The Ohio State University.
There are other possible reasons. Japanese beetles can feed on florets causing the elderberry plants to set fewer fruits. Herbicide damage from 2,4-D or Dicamba is getting more and more common. These chemicals could cause fruits to abort. More studies need to be done to verify this hypothesis.
Mineral nutrient deficiency can be a possible cause too. Boron is one element that is important for fruit set. Tissue testing will help determine if boron levels are too low. If they are, a foliar application of boron will help increase fruit set in the future.
Ripe elderberry fruit cymes. Photo by Gary Gao, The Ohio State University.
Cross pollination can increase fruit set. Elderberries can set fruit when only one cultivar is planted. However, planting two different cultivars that bloom at the same time will significantly increase fruit set cyme size.
Dr. Gary Gao, Professor and Small Fruit Specialist, OSU South Centers
Some of the cold hardy grape cultivars, such as Frontenac, Frontenac Blanc, and Frontenac Gris, have reached veraison at OSU South Centers in Piketon, Ohio. Veraison is the onset of fruit ripening and change of fruit color of grape berries. This is the time when birds started poking fruits for sugar and moisture. All of the punctures are the perfect sites for attracting bees and wasps. These wounds also cause fruits to rot and make grapes less marketable. Birds can peck the fruits off. All of these activities can cause severe yield loss. In the case of wine grapes, fruit and wine quality will also suffer.
Frontenac grapes at veraison. Photo by Gary Gao, The Ohio State University.
Veraison is the time to net the grapes to prevent bird depredation. Many grape growers use this method. There are many different nets out there. Since we grow mostly hybrid grapes on high wire cordon, we put the netting over the row. Our netting material is a black plastic netting that comes in a large roll. We bought a Netter-Getter a few years ago. This tractor mounted net applicator is typically operated by three people. One person drives the tractor and two other people follow behind to drape the net over the entire vine.
Bird netting being applied to grapes. Photo by Gary Gao, The Ohio State University.
If you grower Vinifera grapes, side netting is the preferred method. We do grow several short rows of Cabernet Franc and Regent. They are trained on the Vertical Shoot Positioning system, or VSP.
Typically, the size of the openings is typically half an inch or smaller. Netting is quite an effective method in preventing bird damage. It is by no means perfect since birds can still peck the fruits through the openings. Raccoons and other animals can manage to get the netting to eat the fruits.
Frontenac grapes with bird netting applied. Photo by Gary Gao, The Ohio State University.
Other methods of bird damage prevention are bird distress calls, noise makers like propane cannons, and scarecrows. There is not one method that is 100% effective.
It is important to get the net on the grapes as soon as they turn color. As a matter of fact, it is better to do this sooner than later. Sometimes, birds may just peck the green grapes off just for the fun of it!
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 below:
Crop updates
Vegetables
Cole Crops
Flea beetles are always a difficult foe in brassica plantings since they are often hard to scout for and can leave large amounts of damage in relatively short time frames. In research performed in 2022 by Dr. Ashley Leach, it was found that pyrethroids (e.g., Bifenture EC, Hero) and anthranilic diamides (e.g., Harvanta) performed best to control flea beetle populations and damage. However, if you frequently struggle with flea beetles, consider using their biology against them. You can plant a super tasty preferred brassica (turnip greens) which may keep them away from your primary crop. Alternatively, you can also plant other brassicas (like Kale) that aren’t preferred by flea beetles and can often take a high amount of damage. Often, flea beetles are a problem earlier in the season and later in the season under cooler temperatures.
Cucurbit downy mildew. Symptoms used for identification include necrotic lesions on the upper leaf surface (A) and dark, “velvety” spores on the underside of the leaf (B). Photo source: Hausbeck Lab, Michigan State University.
Powdery mildew is also showing up. Despite their similar names, powdery mildew and downy mildew are not even in the same taxonomic kingdom (downy is a water mold or “oomycete”, while powdery is a true fungus). Consequently, there are no fungicides that pull double-duty in controlling both pathogens. For information on products with efficacy in controlling powdery mildew, check out another recent article on the topic in VegNet.
Squash bugs are out and actively laying eggs. Their copper colored egg masses can frequently be found on the underside of leaves within the veins and on leaf stalks. These pests can vector the viral disease Yellow Vine Decline, as well as cause cosmetic damage to the fruit. Threshold is met if you are finding 1 egg mass per plant. The adults are difficult to control via chemical application, so it is important to frequently scout in order to time insecticide applications to when the egg masses have hatched and nymphs are active on the plant. Spray penetration into the canopy may also limit application efficacy.
Fruiting Vegetables
Tomato Hornworms have been observed in field tomatoes. Their massive defoliation and fruit feeding, as well as frass piles can key you into the area of active hornworm feeding. Hand removal can typically resolve minor infestations. If worms are found with white cocoons on their backs, leave them be. These are beneficial, parasitic wasp cocoons. These wasps will continue to combat hornworms throughout the season.
Tobacco hornworm, a close relative of the tomato hornworm and fellow voracious pest of tomatoes, with parasitic wasp cocoons projecting from its body. Photo by Joe Boggs, OSU Extension.
Verticillium wilt has been a frequent issue in eggplant this season. Initial foliar symptoms present as yellowing and dieback, typically starting at the leaf tip and working down the main vein towards the leaf petiole. While symptoms can provide some idea of disease presence, this disease can only be confirmed by testing the roots and crown at a diagnostic clinic.
Leafy Greens and Herbs
Second generation carrot weevil oviposition will be continuing in parsley (and related Apiaceae crops). Options are limited to control carrot weevil in crops like carrot and parsley. Trapping using Boivin Traps will help direct management efforts, but will be no silver bullet. The threshold used to manage carrot weevil in carrots is to make an insecticide application when weevils reach 1.5 beetles per trap. Celery and carrot have significantly more insecticidal options than parsley (only Baythroid).
Carrot weevil adult. Photo source: University of Massachusetts Extension
Sweet Corn
Corn earworm and European corn borer catches across the state have been relatively low. Western bean cutworm numbers, on the other hand, have been quite high in northern Ohio. See the most recent C.O.R.N newsletter for trap catch data. Western bean cutworm is typically controlled by the same insecticides used for other lepidoptera sweet corn pests. Check out this Michigan State University Extension article on western bean cutworm management considerations.
Japanese beetle pressure has been high this season on numerous crops including sweet corn. There have been reports of the beetles clipping silks prior to pollination, interfering with ear development and quality. This factsheet from Purdue Extension provides several insecticides for Japanese beetle control in corn, many of which are also labeled for sweet corn.
Corn smut is a conspicuous, often sporadic fungal disease affecting sweet corn. A key symptom is the formation of grey galls that are the spore-bearing structures. Rupturing of the smut galls during harvest can taint the ears with black spores, making the sweet corn unmarketable. Corn smut is most prevalent in plants that have undergone physical damage that creates an infection entry point for the pathogen. Preventative control practices consist of crop rotation, destruction of galls before spore dispersal, and minimizing mechanical injury to plants.
Corn smut on sweet corn tassel. Photo by Chris Galbraith, OSU Extension.
Fruits
Tree fruits
Peach harvest has begun in eastern Ohio. Japanese beetle damage has been severe in some apple orchards this season. Codling moth should be slowing down now. Most growers will be making their second insecticide application to control this pest in the next week. Third generation oriental fruit moth will be showing up soon. San Jose Scale pressure should also be steadily decreasing and won’t warrant further intervention until next season. Apple maggot is still moving into orchards in plenty of sites (north and central)- keep those red sticky traps out. Spray if traps are catching >5 flies/trap. We haven’t had too many complaints about stinkbugs in orchards yet, but start trapping now if you are concerned.
Grapes
Herbicide drift damage in vineyards (as well as other specialty crops) is a continued problem. Cassie Brown and Doug Doohan of OSU created a series of fact sheets in the past that address properly preparing for and responding to herbicide drift damage. Find the collection of factsheets here.
Some growers are beginning to apply netting over grape vines to minimize losses from bird damage.
Auxin (group 4) herbicide damage on grapes resulting from spray drift can present as cupped leaves and distorted new growth. Photo by Chris Galbraith, OSU Extension.
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:
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.
