ipm

Ohio State University Extension Specialty Crop Team Newsletter

Editor – Frank Becker, Agriculture and Natural Resources Educator, Wayne County. Contributions made from team members around the state of Ohio. 

Fruit Update

Lingering effects from 2024 drought stress are being reported from various areas of the state. These observations highlight regions where fruit trees continue to struggle to overcome the effects of last year’s drought, with noticeable carryover stress impacting fruit set, tree vigor and fruit development and quality this season. Water management, where you are able, remains a critical factor in maintaining tree vigor and productivity.

The use of broad-spectrum insecticides in some orchards is leading to flare-ups of aphids and mites, as beneficial insect populations are being negatively impacted by the applications. Growers should consider integrating more selective products or IPM-compatible practices to preserve natural enemies.

Harvest of early grape varieties is underway in several regions. Fruit quality appears variable and may impact fermentation decisions for wine and juice production. Growers should also be cautious of the late season products that are applied in the vineyard, as these can also impact juice or wine quality.

We are now in peak adult spotted lantern fly season. Growers should continue to scout for adults, which are active and will soon be laying eggs.

 

Vegetable Update

This season has brought a mix of both expected and unexpected vegetable disease issues: Plectosporium blight in pumpkins, bacterial diseases in multiple crop families, and buckeye rot in tomatoes are being reported by growers across the state. There are also reports of some uncommon or unusual diseases in Ohio such as southern blight, leaf mold in field tomatoes, and pumpkin downy mildew. Some of these diseases challenges can be associated with the abnormally high humidity experienced by much of the state this year.

Squash vine borer (SVB) is causing unusual damage in pumpkins. While not significantly impacting total yield in most fields, the extent and nature of injury are notable. Interestingly, SVB may be partially suppressed by standard sprays targeting cucumber beetles and squash bugs.

Bacterial wilt in cucurbits is persisting into the late season, which is not entirely surprising considering the documented high pressure from cucumber beetles earlier this year.

Populations of corn earworm (CEW) and fall armyworm (FAW) are increasing.

Tar spot has been detected in field corn but has not yet appeared in sweet corn trial plots.

Across all scales of vegetable operations, crop ripening has been slow, contributing to prolonged harvest windows and potentially increasing disease and pest exposure.

Growers utilizing high tunnels have reported facing several key issues this season, including: poor drainage, difficult crop transitions, strategic crop and variety selection decisions.

In field grown vegetables, water-related abiotic disorders continue to show up across the state. These abiotic disorders are often linked to inconsistent irrigation, inconsistent soil moisture or poorly drained soils.

Instances of herbicide drift—some self-inflicted—have continued to be reported. Proper nozzle selection, wind awareness, and sprayer calibration remain critical for minimizing off-target damage.

Pumpkins appear to be ahead of schedule in terms of maturity this year. Growers are preparing for, or already in the midst of an early start to harvest in many locations.

 

Ohio State University Extension Specialty Crop Team Newsletter

Editor – Frank Becker, Agriculture and Natural Resources Educator, Wayne County. Contributions made from team members around the state of Ohio. 

General Update

Pest and disease pressure continues to be a concern, particularly with increased weed pressure this year as well as issues stemming from herbicide drift. While herbicide damage can cause cosmetic damage to perennial crops like fruit trees, it’s important to note that these do not always translate into yield penalties. In areas like orchards and vineyards, patience is key as plants recover from such damage. Please keep in mind that in order for the Department of Agriculture to adequately analyze plant material for herbicide drift, reports to ODA need to be made within 7-1o days of the drift event, and the sooner the better.

Fruit Update

Reports are coming in from several areas about Marssonina leaf blotch affecting apples. This fungal disease thrives in wet conditions and can lead to premature defoliation, weakening the tree. Regular fungicide applications and proper sanitation of fallen leaves can help manage this disease.

Several reports have come in of observed significant loss of raspberry and blackberry plants suspected to be caused by Phytophthora root rot. This is particularly troublesome in raised beds or container plants, where rotation can be difficult to implement. Phytophthora thrives in wet, poorly drained soils, and the disease can rapidly progress if not controlled. It’s important to use resistant cultivars, improve drainage, and avoid overwatering. If you suspect root rot, be sure to send in samples to the Plant and Pest Diagnostic Clinic for a more accurate diagnosis.

Insect activity has been relatively low across most fruit crops, though there have been sporadic reports of spider mites, spotted wing drosophila and third-generation oriental fruit moths (OFM).

Vegetable Update

Cucurbit fields are seeing multiple challenges, including bacterial wilt, which is becoming more widespread. Although the symptoms are visible now, the plants would have been infected with bacterial wilt some time ago via cucumber beetle feeding.  This disease is vectored by the cucumber beetle and can cause wilting and death of the plant. In addition, angular leaf spot has been reported, which is a foliar bacterial disease. Plectosporium has also been observed, primarily in fall vine crop fields. Plectosporium can cause lesions to form on the stems and handles, causing handle integrity issues in these crops. Lesions may also form on the fruit, directly impacting fruit quality and marketability.

Recent field collected samples have shown bacterial issues on dill, which could be a sign of improper plant spacing, moisture issues, or bacterial contamination. The leaves are exhibiting typical signs of bacterial infection, so reducing overhead irrigation and removing affected plants can help minimize spread.

In tomatoes, pressure continues to increase from Septoria leaf spot, early blight and bacterial spot. These diseases tend to show up during wet periods and cause significant defoliation, which can reduce yields. Applying fungicides and bactericides to affected crops and practicing good sanitation and crop rotation can reduce the chances of recurrence.

On the insect side, activity has been relatively light. Some growers have observed garden millipedes feeding on decaying plant material, particularly in areas affected by bacterial wilt. These are only secondary pests in these cases and no control is needed. Flea beetle numbers are sporadic, and both imported cabbage worms and diamondback moths are being seen, but with thorough scouting and timely management decisions, can be effectively controlled.

Onions still in the fields have been under attack from salt marsh caterpillars and thrips. Both pests can cause significant damage, with thrips often being the primary concern due to their ability to spread viruses and cause leaf damage. Regular scouting is critical for managing these pests.

A few growers have reported broad mite issues in certain fields. Broad mites are particularly damaging in high humidity conditions and can cause distorted leaf growth. With the high weed pressure this year, it’s important to monitor how these pests may persist in weed refuges, potentially leading to future problems in subsequent seasons. When selecting miticides, ensure that you are reading the label to confirm that the products are listed for control of broad mites. Products listed for control of only red mites or two-spotted spider mites will not control broad mites.

Ohio State University Extension Specialty Crop Team Newsletter

Editors – Dr. Ashley Leach, State Extension Specialist- Specialty Crop Entomology, and Frank Becker, Agriculture and Natural Resources Educator, Wayne County. Contributions made from team members around the state of Ohio. 

General Note

As issues (biotic or abiotic) are observed throughout the season, growers should consider the importance of supporting plant health through fertility management, both to address deficiencies as well as avoiding over fertilization. This can be especially important in older plantings, such as established perennial fruit crops, where this aspect of management may have been neglected. Taking soil tests and tissue tests is encouraged to get a better picture of overall plant health status. This discussion should also include consideration for the importance of transplant and seedling health management. While these management areas may have some seasonality to them, in reality, they are year round commitments that are foundational to integrated plant health management.

Fruit Crops 

As the summer has progressed, insect issues have continued to be causing frustrations for fruit growers. Spotted wing drosophila have seemed to establish some significant populations, evident by consistently significant trap catches in small fruits. Other insect issues such as stink bugs have been found in the orchards, but populations remain fairly low and are mostly concentrated around the edges. Be sure to walk your blocks and check for any signs of stink bug activity.

Stink Bug trap in an orchard, F. Becker photo.

Codling moth and Oriental fruit moth trap counts have ticked up slightly from previous weeks. Numbers are still low and nearly all sites do not require intervention, but continue to monitor trap catches closely. Keep your apples protected from Apple maggot, which is still active and capable of infesting fruit. If you’re using a yellow card, spray when you catch 1 fly per trap; if using a red baited sphere, spray when you catch 5 flies per trap. Some growers have reported Japanese beetle feeding, particularly around the edges of orchards. This pest rarely causes major issues, but if your planting is young or stressed, consider an insecticide application.

Vegetable Crops 

Photo Credit – Dr. Ashley Leach, OSU

Special to the Specialty Crop Team from Dr. Ashley Leach: Managing pests when pollinators are in the field is challenging, especially in crops like cucurbits, which face pressure from pests like squash bugs and cucumber beetles during bloom. Integrated Pest and Pollinator Management (IPPM) offers a realistic framework for managing pests while minimizing unintended harm to pollinators and beneficial insects.

Key practices include:
  1. Monitor pest pressure and use thresholds when possible to guide insecticide decisions. For example, treating only when beetle densities exceed 1 per plant can reduce sprays, improve pesticide performance, and cut costs.
  2. Choose insecticides with lower toxicity to pollinators—such as kaolin clay (e.g., Surround) or acetamiprid—when applying during bloom. Apply in the late afternoon or evening to reduce bee exposure.

    Photo Credit – Dr. Ashley Leach, OSU

  3. Avoid tank mixes with multiple broad-spectrum products, especially combinations with certain fungicides (e.g., sterol biosynthesis inhibitors), which can increase toxicity to pollinators.
  4. Leave unsprayed refuge areas or field borders, when feasible, to conserve pollinators and natural enemies that contribute to pest suppression.
  5. Rotate insecticides by mode of action to slow resistance and protect natural enemies that help keep secondary pests in check.
IPPM doesn’t have to mean compromising on pest control. With small adjustments, growers can reduce input costs, protect pollination services, and maintain high-quality yields. even during bloom.