Vegetable IPM Update 6/5/25

Greetings from the Veg IPM team!

Sweet Corn

With the hot weather, we’re starting to see sweet corn really coming along. Some plantings of sweet corn are silking (especially in the south), so it’s time to think about corn earworm management. Moth captures in the Southern part of the state (see map) are indicating that 4 and even 3 day intervals are necessary in some areas. Rotation is important for avoiding resistance, and there are four IRAC groups that are registered in silking sweet corn: 1 (carbamates), 3 (pyrethroids), 5 (spinosyns), and 28 (diamides). Corn earworm is at least partly resistant to several pyrethroids, so a spray program should not rely solely on pyrethroids, although they can be useful in tank-mixes or as pre-mixed products, such as Besiege or Elevest (Group 28 + Group 3). For detailed information about resistance and potential spray programs, the University of Delaware has an excellent resource on corn earworm management.

Spray intervals based on nightly pheromone moth captures for the southern part of New Jersey. Note that not all locations in the IPM program are currently trapping. This map is based on the following thresholds: 0 moths = 6-7 day schedule, 1 moth = 5 day spray schedule, 2-20 moths = 4 day spray schedule, 20+ moths = 3 day spray schedule.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle activity seems to be slowing down some, but they are still active in various cole crops. This year, they have been especially prevalent in lacinato kale, Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

Two caterpillars on brassica leaves. Diamondback moth caterpillar on the left is smooth and tapered at each end. Imported cabbageworm on the right is fuzzy.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re still seeing caterpillar activity in cabbage and other cole crops. Treatment thresholds vary between crops and growth stage, but for heading cole crops between early vegetative and cupping, the treatment threshold is 30%. At this stage, sprayable Bt products (IRAC 11A) such as Dipel, Xentari, or Javelin can be effective on young imported cabbage worm caterpillars. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). Diamondback moth has resistance to many insecticide groups, and pyrethroids (IRAC 3A) are not effective for their management. For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

Tomatoes

In high tunnels and field plantings of tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. We have seen aphid populations decline over the last couple of weeks without spray, probably due to natural enemies predation. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations. We’ve seen very few Colorado potato beetles (CPB) in tomatoes, so while no controls are needed yet, we’ll keep an eye out for increasing populations.

Eggplants

In eggplants we have seen some damaging populations of CPB. For plants under 6 inches, 2 small/1 large larvae per plant is the threshold, while for plants taller than 6 inches, the threshold is 4 small/2 large larvae per plant. Adults are hard to kill, so sprays should target the larvae, with younger/smaller larvae being more vulnerable than older larvae. CPB has resistance to many classes of insecticides and is notorious for quickly developing resistance to new ones, so plan to rotate IRAC groups if you’ve already treated or need to treat more than once. If you haven’t used a neonic (IRAC 4) at planting or in the drip, you can use a foliar neonic like Assail or a spinosyn like Entrust or Radiant (IRAC 5). Avoid IRAC 5 groups if you’ve already used a neonic, because there is risk of cross resistance. Diamide products like Coragen and Exirel (IRAC 28), Rimon (IRAC 15), and Torac (IRAC 21A) should all give good control.

On the left there are two orange beetle larvae on an eggplant leaf. On the right there is a large beetle with black and white striped wing covers and an orange head and abdomen, also on an eggplant leaf.

Left: Colorado potato beetle larvae and feeding damage on an eggplant leaf. Right: Adult Colorado potato beetle. Photos by Maria Cramer.

Diseases

We’ve detected bacterial diseases of tomatoes and peppers on a few farms in the central and northern parts of the state (see photos below). Copper may help mitigate symptoms, but some strains have developed resistance due to continued copper use. Other products that may help include Actigard and Quintec. Otherwise, properly managing nutrients and growing conditions for the plant will be crucial for reducing the severity of this disease.

Bacterial leaf spot on tomato. Photo by Amanda Quadrel

Bacterial leaf spot on pepper. Photo by Amanda Quadrel.

 

 

 

 

 

 

 

 

 

 

 

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

Vegetable IPM Update 5/30/25

Greetings from the Veg IPM team! The program welcomes Martina Lavender and Coco Lin as the first two scouts of the season, servicing North and Central Jersey respectively.

Sweet Corn

We’ve put out corn earworm pheromone traps throughout the state. While silking corn is the main target of CEW activity, we set the traps early to detect overwintering moths. So far, we haven’t spotted any serious corn pests through visual inspection.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle remain active in various cole crops. This year, they have been especially prevalent in lacinato kale, Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

 

Left: Smooth caterpillar, tapered at each end. Right: fuzzy caterpillar. Both are on brassica leaves.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re seeing caterpillar activity (imported cabbageworm in the North and diamondback moth in the South) in cabbage and other cole crops. Treatment thresholds vary between crops and growth stage, but for heading cole crops between early vegetative and cupping, the treatment threshold is 30%. At this stage, sprayable Bt products (IRAC 11A) such as Dipel, Xentari, or Javelin can be effective on young imported cabbage worm caterpillars. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). Diamondback moth has resistance to many insecticide groups, and pyrethroids (IRAC 3A) are not effective for their management. For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

Tomatoes

In high tunnels and the first field plantings of tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. We have seen aphid populations decline over the last couple of weeks without spray, probably due to lady beetle predation and parasitism from wasps. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations. We’ve seen very few Colorado potato beetles, so while no controls are needed yet, we’ll keep an eye out for increasing populations.

Colorado potato beetle adult in tomato

Diseases

With little break in the rainy weather, we’re seeing plants stressed by flooding and some bacterial and fungal diseases popping up in tomatoes, peppers, and cole crops. If you’re seeing disease symptoms and need a diagnosis, samples can be sent to Rutgers Plant Diagnostic Laboratory.

We’ve detected bacterial leaf spot of tomatoes and peppers on a few farms in the central and northern parts of the state (see photos below). Copper may help mitigate symptoms, but some strains have developed resistance due to continued copper use. Other products that may help include Actigard and Quintec. Otherwise, properly managing nutrients and growing conditions for the plant will be crucial for reducing the severity of this disease.

Bacterial leaf spot on tomato

Bacterial leaf spot on pepper

 

 

 

 

 

 

 

 

 

 

Despite the rain, we also saw some rhizoctonia in cole crops, which shows up when transplant plugs dry out. For more information on this disease, check out the recent update in the PPA.

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

Vegetable IPM Update 5/15/25

Greetings from the Veg IPM team! No major changes have taken place between last week and this week, and with the rainy weather, scouting has been limited.

Sweet Corn

We’ve put out corn earworm pheromone traps throughout the state. While silking corn is the main target of CEW activity, we set the traps early to detect overwintering moths, which have become more common with warmer winters. As a reminder, we’re no longer using blacklight traps as of this year, and we’ll be reporting pheromone trap counts in the Plant Pest Advisory as the season progresses. So far, we haven’t spotted any corn pests through visual inspection.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle are active in various cole crops. This year, they have been especially prevalent in Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

 

Two picture, the picture on the left shows a smooth caterpillar that tapers at both ends. The picture on the right shows a caterpillar that is fuzzy all over and does not taper at either end.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re seeing caterpillar activity (imported cabbageworm and diamondback moth) in cabbage and other cole crops. Treatment thresholds vary between crops and growth stage, but for heading cole crops between early vegetative and cupping, the treatment threshold is 30%. At this stage, sprayable Bt products (IRAC 11A) such as Dipel, Xentari, or Javelin can be effective on young caterpillars. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

 

Tomatoes

In high tunnels and the first field plantings of tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations.

 

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

 

Vegetable IPM Update 5/08/25

Sweet Corn

We’ve put out corn earworm pheromone traps throughout the state. While silking corn is the main target of CEW activity, we set the traps early to detect overwintering moths, which have become more common with warmer winters. As a reminder, we’re no longer using blacklight traps as of this year, and we’ll be reporting pheromone trap counts in the Plant Pest Advisory as the season progresses.

Cole Crops 

A shiny black beetle with straight antennae stands on a leaf surrounded by circular feeding holes.

Flea beetle surrounded by feeding damage. Picture by Maria Cramer.

Flea beetle are active in various cole crops. This year, they have been especially prevalent in Napa cabbage and bok choy. Young plants are especially vulnerable to attack from flea beetles. The treatment threshold for flea beetles in heading cole crops is 50% infestation.

 

Two picture, the picture on the left shows a smooth caterpillar that tapers at both ends. The picture on the right shows a caterpillar that is fuzzy all over and does not taper at either end.

Left: Diamondback moth caterpillar, showing characteristic tapering at each end. Right: Imported cabbageworm caterpillar showing characteristic fuzziness. Pictures by Maria Cramer.

We’re seeing caterpillar activity (imported cabbageworm and diamondback moth) in cabbage and other cole crops. Treatment thresholds vary between crops and growth stage, but for heading cole crops between early vegetative and cupping, the treatment threshold is 30%. At this stage, sprayable Bt products (IRAC 11A) such as Dipel, Xentari, or Javelin can be effective on young caterpillars. Other materials approved for caterpillar control include Entrust/Radiant (IRAC 5), Proclaim (IRAC 6), Torac (IRAC 21A), and Exirel (IRAC 28). For Bt products and contact insecticides, coverage on the undersides the leaves is essential.

 

Tomatoes

In high tunnel tomatoes, we’re seeing limited aphid, thrips, and spider mite activity. If dealing with primarily aphids, products such as Beleaf (IRAC 29) are recommended, especially if plants have reached the flowering stage. For thrips, Entrust, Radiant (IRAC 5) and Torac (IRAC 21A) can be used. For spider mites, Nealta (IRAC 25) is an effective material that is more friendly to beneficial insects, but Portal (IRAC 21A) and other materials can be used to manage populations.

 

Please consult the Mid-Atlantic Commercial Vegetable Production Guide for a more comprehensive list of materials that are labeled for specific crops and pests. As always, be sure to follow label rates and application instructions.

Authors: Amanda Quadrel (Northern NJ Veg IPM coordinator) and Maria Cramer (Southern NJ Veg IPM coordinator)

 

Take a quick survey to help with Field Equipment Sanitation Research!

In a Specialty Crop Research Initiative (SCRI) grant designed to guide future solution and resources centered around field equipment sanitation, collaborative team comprising pathologists, weed scientists, agronomists, and experts in agricultural equipment sanitation has crafted a questionnaire. This questionnaire is designed to gather growers’ input on their current practices and determine the necessity for implementing new ones.

The research will develop a more comprehensive understanding of the challenges associated with field equipment sanitation and work toward developing solutions that are effective, implementable and sustainable.

To introduce the survey and forthcoming research effort, Dr. Matt Grieshop, lead PI on this project indicates that “We are a group of agricultural research and extension professionals from across the United States that are curious about grower and agricultural professional perceptions about the importance of field equipment sanitation to mitigate the spread of organisms that pose human health, weed, plant pathogen or other risks.

Agricultural field equipment includes tillage implements, tractors, harvesters, cultivation equipment, trucks, trailers, sprayers, mowers, or any other piece of equipment that is shared across fields.

This information will be solely used to help frame future research questions and outreach activities.  It will not be published or distributed in any form. Answering should take 5 minutes or less and is completely voluntary and anonymous.

Your participation is invaluable to future developments in the industry regarding food safety and equipment sanitation. We need more inputs from New Jersey specialty crops growers so that they have a say on the direction that field equipment sanitation research will take in the future!

To contribute, visit here or scan the QR code below.


If you have questions, comments or concerns contact Dr. Matt Grieshop at mgriesho@calpoly.edu or Dr. Thierry Besancon at thierry.besancon@rutgers.edu.

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