Vegetable Crops Edition

Seasonal updates and alerts on insects, diseases, and weeds impacting vegetable crops. New Jersey Commercial Vegetable Production Recommendations updates between annual publication issues are included.
 
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June 13, 2025 and

Veg IPM update 6/12/25

Greetings from the Veg IPM team!

Sweet Corn

Early plantings of sweet corn are silking throughout New Jersey. Moth captures in much of the state (see map) are indicating that 4 day spray intervals are necessary, with pockets of higher pressure requiring 3 day intervals, and a few with lower pressure, indicating 5 or 6 day intervals. 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. We’ve also seen some instances of European corn borer and corn earworm feeding in tassels of scouted corn, but for the most part, their numbers have not been high enough to warrant control efforts prior to silking.

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.

 

Tomatoes

In southern New Jersey we’re seeing high thrips counts both in tunnels and in the field, although numbers have been higher in tunnels. We consider more than 5 thrips on 10 leaves a high count. Other guides suggest 3-5 thrips per flower or the presence of stippling damage on fruit to be a treatment threshold. Thrips management is especially important because of their ability to vector tomato spotted wilt virus (TSWV), a growing concern in New Jersey where we have resistance-breaking strains. TSWV has already been seen on farms this season. Thrips management can be especially challenging in high tunnels due to a lack of products. Minecto Pro (IRAC 28 + 6) and Exirel (IRAC 28) can be used in tunnels, but only suppress thrips populations (this means they reduce numbers, but do not eradicate them). In the field, Entrust/Radiant (IRAC 5) can be used as well as Torac (IRAC 21A) and Harvanta (IRAC 28). We do not recommend pyrethroids or neonicotinoids for thrips due to resistance in different thrips species. Refer to the previous link for a complete list of best management practices for thrips and TSWV.

We’re also seeing limited aphid 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. However, natural enemies often control aphids, so if counts are low and natural enemies like lacewings, lady beetles, or parasitoid wasps are present, you may avoid sprays. 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. Colorado potato beetles are especially prevalent in eggplants. Please consult the Mid-Atlantic Commercial Vegetable Production guide for appropriate materials for CPB control.

6 tiny light-colored thrips on a tomato leaf.

Thrips on a tomato leaf. Photo by Maria Cramer.

Peppers

Peppers have been relatively pest-free so far this season, other than patches of aphids and a few disease issues. As in tomatoes, aphids are often controlled by natural enemies, and using selective insecticides can favor natural enemy activity preventing outbreaks. Before fruit set, the threshold for treatment is 10 aphids per leaf. After fruit set the threshold is 5 aphids per leaf. There are many products registered for aphids in peppers. similar to tomatoes, if only dealing with aphids, we recommend using Beleaf (IRAC 29).

 

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 continue to see caterpillar activity in heading 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%. For very small caterpillars, 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 (the primary caterpillar found in southern NJ) 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.

As always, 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.

Filed Under: Commercial Ag Updates, Organic Production, Uncategorized, vegetable, Vegetable Crops
June 13, 2025

Agritourism Marketing Survey

WVU Extension and other colleagues are trying to understand how we can better help you with your Agritourism Marketing. It will tremendously help us to help you in the future.

Please take a few minutes (at most 5 minutes) to answer the questions here: https://s.uconn.edu/agritourism-marketing

Filed Under: Christmas Trees, Fruit, Vegetable Crops Tagged With: , , ,
June 10, 2025

Basil downy mildew samples wanted by Rutgers!

Calling all commercial basil growers, researchers, home gardeners, and basil enthusiasts!
Our team at Rutgers University, UMass Amherst, Bar-Ilan University, and University of Florida
are asking for your help! Basil production is still threatened by the devastating Basil Downy
Mildew disease and current methods of prevention and resistance are wavering. It appears that
the pathogen is evolving rapidly, and we need your help to understand this phenomenon. We are
asking anyone who observes basil downy mildew on their plants to send infected leaf samples to
our researchers listed below and to report their infection to the following website:
https://basil.agpestmonitor.org/. These samples will be used to better understand the existing
pathogen populations and help drive solutions towards the downy mildew problem. This problem
cannot be solved alone, and we thank you!

Shipping Instructions:
Please collect as many infected leaves showing sporulation (or yellowing) as possible and wrap
in a dry paper towel before placing inside a sandwich bag. Seal the sandwich bag partially
(leaving about a quarter open) before placing in an envelope addressed with the information
below:

Rutgers University Mailing Information:
B.A.S.I.L.
Foran Hall, Rm 392
59 Dudley Rd
New Brunswick, NJ 08901
Please address any questions or concerns you may have to Robert Mattera III
(robert.mattera@rutgers.edu)

 

Filed Under: Vegetable Crops Tagged With:
June 6, 2025 and

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)

Filed Under: Organic Production, Plant Diagnostic Lab, Uncategorized, vegetable, Vegetable Crops Tagged With: , , , ,
June 2, 2025 , , and

High Temperatures Predicted this Coming Week – Ways to Prevent Heat Stress

OSHA Safe + Sound Header for Heat Illness Prevention

Heat exposure for agricultural laborers should be a consideration when working outside and even in non-airconditioned buildings. When a person’s ability to adapt to heat stress is exceeded, exposure can lead to reduced productivity, mistakes in job performance, increased workplace incidents, and/or heat-related illnesses. Each person’s heat tolerance varies and several factors including type of physical activity, fitness level, underlying health issues, temperature, sun exposure, air movement (wind), and humidity can dramatically impact the potential for heat stress. To determine the level of heat risk, employers should consider the job, the environment, and the worker.

Evaluate the Risk of Heat Stress:
Monitoring the environmental conditions during work times to make management decisions for workers is an important part of preventing heat-related illnesses. Temperature is not the only factor in implementing heat stress management. Humidity is another important consideration. The heat index is a measure of how hot it feels when the relative humidity is factored in with the actual air temperature.

An environmental heat assessment should account for the following factors: air temperature, humidity, radiant heat from sunlight or other artificial heat sources, and air movement. OSHA recommends the use of wet bulb globe temperature (WBGT) monitor to measure workplace environmental heat. OSHA provides this link to calculate the WBGT for a specific location. There is also a NIOSH/OSHA Heat App for Android and iPhone devices that uses the Heat Index as a screening tool.

Management Suggestions for Enhancing Heat Tolerance:
Acclimatization (to heat) is a process of adaptation that involves a stepwise adjustment to heat over a week or sometimes longer. An acceptable schedule for achieving acclimatization is to limit occupational heat exposure to one-third of the workday during the first and second days, one-half of the workday during the third and fourth days, and two-thirds of the workday during the fifth and sixth days. The acclimatization procedure should be repeated if a person misses workdays after days off due to illness, vacation, or other reasons for missing one week or more of job duties.

Fluid replacement:
Provide adequate drinking water for all employees. Recommend to employees they drink plenty of water before work shifts, during work, and after work. Simply relying on feeling thirsty will not ensure adequate hydration. To replace the four to eight quarts of sweat that may be produced in hot environments, people require one-half to one cup of water every 20 minutes of the workday. Potable drinking water kept at a temperature of 59°F or less is recommended.

Physical Fitness: Physical fitness is extremely important. The rate of acclimatization is a function of the individual’s physical fitness. The unfit worker takes 50 percent longer to acclimate than one who is fit.

Increasing Safe Work Practices:
To find management and guidance tools for determining whether to implement heat stress management plans refer to the CDC documents on Heat Stress and Work/Rest Schedules.

The following list of management options should be considered to prevent heat stress for workers:

  • Limit exposure time. Schedule as many physical work activities as practical for the coolest part of the day (early morning or late afternoon). Employ additional help or increase mechanical assistance, if possible, to lighten individual workloads.
  • Minimize heat exposure by taking advantage of natural or mechanical ventilation (increased air velocities up to 5 mph increase the rate of evaporation and thus the rate of heat loss from the body) and heat shields/shade when applicable.
  • Take rest breaks at frequent, regular intervals, preferably in a cool environment sheltered from direct sunlight. Anyone experiencing extreme heat discomfort should rest immediately and be provided with first aid for heat stress.
  • Wear clothing that is permeable to air and loose fitting. Generally, less clothing is desirable in hot environments, except when the air temperature is greater than 95°F or a person is standing next to a radiant heat source. In these cases, covering exposed skin can reduce the risk of heat stress.
  • A buddy system may also be helpful. It depends on a fellow worker’s ability to spot the early signs of heat stress, such as irritability, confusion, or clumsiness. A ready means of cooling should be available in work areas where heat illness might occur.
Filed Under: Blueberry, Commercial Ag Updates, Cranberry, Field, Forage & Livestock, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, vegetable, Vegetable Crops, Wine Grape Tagged With: ,
May 29, 2025

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)

Filed Under: Organic Production, Plant Diagnostic Lab, Uncategorized, vegetable, Vegetable Crops Tagged With: , , , ,