- Cucurbit downy mildew has been confirmed on cucumber in New Jersey. To date, cucurbit downy mildew has been reported on cucumber and melon in the mid-Atlantic region. All cucumber growers need to add a downy mildew-specific fungicide to their weekly fungicide programs. All cucurbit growers need to scout on a regular basis.
- Dickeya dianthicola was confirmed in New Jersey on ‘Dark Red Chieftain’ originating from New Brunswick, Canada this past week. This is the third report of Dickeya on seed originating from Canada this summer. ‘Yukon Gold’ and ‘Reba’ from New Brunswick, Canada have also tested positive. In total, Dickeya dianthicola has been confirmed in 16 states to date. All potato growers are encouraged to scout fields and report any suspect plants/tubers. The best method for keeping your potato operation Dickeya-free is to adopt your own 0% Dickeya-tolerance policy.
- Pepper anthracnose is being reported in southern New Jersey.
- Cucurbit powdery mildew is active on all cucurbit crops.
- There have been no new reports of Late blight this this past week.
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.
Subscriptions are available via EMAIL and RSS.
Quick Links:
NJ Commercial Vegetable Production Recommendations
Rutgers Weather Forecasting - Meteorological Information important to commercial agriculture.
September 6, 2016 Andy Wyenandt
Vegetable Disease Briefs – 9/6/16
August 31, 2016 Kris Holmstrom and Joe Ingerson-Mahar
Veg IPM Update: Week Ending 8/31/16
Sweet Corn
A few European corn borer (ECB) adults have been captured this past week. At the present time, highest activity is in the Cape May-Cumberland County border area (see ECB map). Earlier ECB catches were extremely low, and these moths, likely representing a partial third flight, will not present much of a threat to host crops. This is particularly true in light of the dominance this year of fall armyworm (FAW). FAW will probably remain the larger threat, and treatments for this pest will eliminate ECB in the process. As always, consider treating when the number of infested plants in a 50 plant sample exceeds 12%. Any planting remaining at or above threshold as it proceeds to full tassel should be treated, as this is the last stage at which ECB larvae will be exposed and vulnerable to insecticidal sprays. See the 2016 Commercial Vegetable Recommendations Guide for insecticide choices.
The highest nightly ECB catches for the previous week are as follows:
| Eldora 2 | Georgetown 1 |
| Allentown 1 | Lawrenceville 1 |
| Crosswicks 1 | Little York 1 |
| Folsom 1 | Pennington 1 |
There has been no change in the fall armyworm (FAW) situation. Infestations continue throughout NJ, with high infestation rates in all parts of the state. This pest is devastating to small corn plants, and in fact the worst infestations are currently in shorter whorl stage plantings. Fields down to seedling stage should be scouted weekly for signs of infestation. We should expect this pest to be with us for the remainder of the sweet corn growing season. Treat when FAW alone or in combination with ECB damage exceeds 12% plants infested. FAW do not respond well to pyrethroid insecticides. The most useful products are those in the IRAC group 28 class (Coragen, Exirel) or the IRAC group 5 class (Radiant, Entrust), or combination products including these classes. See the 2016 Commercial Vegetable Recommendations Guide for insecticides effective against FAW.
August 25, 2016 Andy Wyenandt
Vegetable Disease Briefs – 8/25/16
- Cucurbit downy mildew has been confirmed on cucumber in New Jersey. To date, cucurbit downy mildew has been reported on cucumber and melon in the mid-Atlantic region. All cucumber growers need to add a downy mildew-specific fungicide to their weekly fungicide programs. All cucurbit growers need to scout on a regular basis.
- Dickeya dianthicola has been confirmed in 16 states to date. All potato growers are encouraged to scout fields and report any suspect plants/tubers. The best method for keeping your potato operation Dickeya-free is to adopt your own 0% Dickeya-tolerance policy.
- Pepper anthracnose is being reported in southern New Jersey.
- Cucurbit powdery mildew is active on all cucurbit crops.
- Late blight was reported on tomato near Blacksburg, Virginia this past week.
August 24, 2016 Kris Holmstrom and Joe Ingerson-Mahar
Veg IPM Update: Week Ending 8/24/16
Sweet Corn
European corn borer (ECB) adult activity has declined to nearly nothing at this time, and no map image is in this edition. The second flight was extremely low, with fall armyworm injury much more dominant this year. It is possible that we will have a partial third flight, but as the second was so low, it is not likely that it would be of much consequence. As always, consider treating when the number of infested plants in a 50 plant sample exceeds 12%. Any planting remaining at or above threshold as it proceeds to full tassel should be treated, as this is the last stage at which ECB larvae will be exposed and vulnerable to insecticidal sprays.
See the 2016 Commercial Vegetable Recommendations Guide for insecticide choices.
The highest nightly ECB catches for the previous week are as follows:
| Beckett 1 | Lawrencevile 1 |
| Chester 1 | Little York 1 |
| Crosswicks 1 | Matawan 1 |
| Georgetown 1 |
Fall armyworm (FAW) infestations continue throughout NJ, with high infestation rates now appearing in all parts of the state. This pest can be devastating to small corn plants, and in fact the worst infestations are currently in shorter whorl stage plantings. Fields down to seedling stage should be scouted weekly for signs of infestation. Treat when FAW alone or in combination with ECB damage exceeds 12% plants infested. FAW do not respond well to pyrethroid insecticides. The most useful products are those in the IRAC group 28 class (Coragen, Exirel) or the IRAC group 5 class (Radiant, Entrust), or combination products including these classes. See the 2016 Commercial Vegetable Recommendations Guide for insecticides effective against FAW.
August 22, 2016 Andy Wyenandt
Dickeya dianthicola reported in 4 more states: IN, MO, MI, and TX
Dickeya dianthicola has been reported in four more states (Indiana, Missouri, Michigan, and Texas). Using PCR test results and North American Certified Seed Potato Health Certificates to track Lot no., Dickeya dianthicola has been reported in 16 states (DE, FL, MD, MA, NJ, NY, NC, PA, RI, VA, WV, OH, IN, MO, MI, and TX) on at least nine potato varieties to date in 2016. These varieties include: ‘Reba’, ‘Superior’, ‘Vivaldi’, ‘Norwis’, ‘Snowden’, ‘Yukon Gold’, ‘Beacon Chipper’, ‘Kennebec’, and ‘Atlantic’. Test results and additional information are still forthcoming. Known sources of infested seed have originated from at least two suppliers in Canada and 11 seed suppliers in Maine. In some cases, multiple varieties of Dickeya-infested seed have originated from the same source in Maine. Potato growers, crop consultants, and Extension personnel in states which grow and are still harvesting potatoes from Maine or New Brunswick, Canada should remain vigilant by scouting their fields for Dickeya symptoms, particularly those varieties which have tested positive for Dickeya, on a regular basis and by submitting any suspect samples for diagnostic testing.
Dickeya dianthicola has been detected in the US in the past, and because of this, APHIS just recently announced that the pathogen has been designated as a non-reportable/non-actionable pathogen despite its potential to cause 100% crop loss. A link to the USDA/APHIS website for information on Dickeya dianthicola detection and control can be found here. Importantly, there is no current policy in place designed specifically for regulating and/or controlling Dickeya dianthicola in potato in Maine or Canada.
The best method for keeping your potato operation Dickeya-free is to adopt your own 0% Dickeya-tolerance policy.
August 17, 2016 Kris Holmstrom and Joe Ingerson-Mahar
Veg IPM Update: Week Ending 8/17/16
Sweet Corn
European corn borer (ECB) adult activity is very low. Areas of highest activity continue to be in the central counties, and particularly Mercer County (see ECB map). Much of the ECB feeding that is currently in corn is overshadowed by FAW damage. As always, consider treating when the number of infested plants in a 50 plant sample exceeds 12%. Any planting remaining at or above threshold as it proceeds to full tassel should be treated, as this is the last stage at which ECB larvae will be exposed and vulnerable to insecticidal sprays.
See the 2016 Commercial Vegetable Recommendations Guide for insecticide choices.
The highest nightly ECB catches for the previous week are as follows:
| Farmingdale 2 | Crosswicks 1 | Old Bridge 1 |
| Georgetown 2 | Denville 1 | Princeton 1 |
| Allentown 1 | Lawrenceville 1 | |
| Blairstown 1 | New Egypt 1 |
Fall armyworm (FAW) infestations continue throughout NJ, with high infestation rates now appearing in all parts of the state. This pest can be devastating to small corn plants, and in fact the worst infestations are currently in shorter whorl stage plantings. Fields down to seedling stage should be scouted weekly for signs of infestation. Treat when FAW alone or in combination with ECB damage exceeds 12% plants infested. FAW do not respond well to pyrethroid insecticides. The most useful products are those in the IRAC group 28 class (Coragen, Exirel, Belt) or the IRAC group 5 class (Radiant, Entrust), or combination products including these classes. See the 2016 Commercial Vegetable Recommendations Guide for insecticides effective against FAW.
Corn earworm moth (CEW) activity has increased significantly over the weekend. While the increases are geographically inconsistent, a number of blacklights registered much higher numbers since late last week. The higher catches are generally in the western half of the state, but increases have been detected all over NJ (see CEW map). Catches in DE are lower than some of our NJ catches; particularly in the western NJ traps, hinting that some of these moths may have come from more westerly sources. This current population is still lower than we traditionally get in mid-August. More CEW may continue to arrive in advance of frontal low pressure systems. Growers should be checking CEW activity frequently, and adjust spray schedules according to local activity.
The highest nightly CEW catches for the previous week are as follows:
| Hillsborough 5 | Pedricktown 3 | Green Creek 2 |
| Allentown 4 | Centerton 2 | Tabernacle 2 |
| East Vineland 4 | Denville 2 | Woodstown 2 |
| Jones Island 3 | Georgetown 2 | Morristown 1 |
The limited CEW pheromone trap network in the southern counties also increased over the weekend. As with blacklight traps, catches are not geographically consistent, although numbers are much higher overall (see CEW pheromone map). The low number of traps results in broad areas of color within the map. It is critical that growers monitor local CEW moth numbers. At present, this population constitutes a significant threat to silking corn.
The highest nightly CEW pheromone trap catches for the previous week are as follows:
| Green Creek 70 | Monroeville 23 | Beckett 10 |
| Elm 32 | Pedricktown 18 | Berlin 10 |
| Woodstown 28 | East Vineland 11 |
For silking sweet corn, the following spray schedules are warranted.
Silking Spray Schedules*:
South – 3 days
Central – 3-4 days
North – 4-5 days
*These recommendations are based on regional catches.
Brown Marmorated Stinkbug (BMSB)
BMSB numbers increased in many NJ blacklight traps this past week. Higher activity may be found into the central counties now. Hot weather may be causing adults to be more active, and nymphs have been discovered in pepper and corn plantings. It is important that host crops like peppers be scouted regularly for the presence of BMSB and other stinkbugs at this time. It is often most productive to walk slowly down pepper rows, scanning plants ahead. BMSB and other stink bugs tend to bask near the tops of plants, especially in the morning hours.
The highest nightly BMSB trap catches for the previous week are as follows:
| Matawan 9 | Georgetown 7 | Pedricktown 6 |
| Centerton 8 | Springdale 7 | Pennington 6 |
| East Vineland 8 | Woodstown 7 | Allentown 5 |
| Farmingdale 8 | Medford 6 | Old Bridge 5 |
Pumpkins and Winter Squash
Powdery mildew (PM) is active on pumpkin and winter squash fields throughout NJ. The action threshold for commencement of the protectant fungicide program for PM is 2 lesions per 100 older leaves. See the 2016 Commercial Vegetable Recommendations Guide for a list of appropriate protectant fungicide rotations for PM control.
Down
y mildew (DM) is present on cucumbers in all parts of NJ (see photo at left). DM has been reported on the eastern shore of Virginia on butternut squash. While this site may not currently be a direct threat to NJ pumpkin and winter squash acreage, it is an indication that races of the pathogen that are capable of infecting these important crops are getting closer. All growers should be applying appropriate protectant fungicides plus DM specific materials to cucumbers and cantaloupes at this time, and preparing to do the same on pumpkins and winter squash (See Dr. Andrew Wyenandt’s Cucurbit Downy Mildew Update in today’s Plant and Pest Aevisory). DM lesions appear as yellow areas on the upper leaf surface with leaf veins making distinct borders to the lesions. On the lower leaf surface, beneath the lesions, dark spores may be seen if conditions are moist. For more information on the regional presence of DM as well as comprehensive, weekly forecasts, see the following website: http://cdm.ipmpipe.org . At this time, NJ is at elevated risk for further spore deposition and infection from sources to the south and west according to the Cucurbit Downy Mildew Forecast.
Peppers and Tomatoes
Stinkbugs continue to be found in scouted fields along with two-spotted spider mites (TSSM). This latter pest is particularly favored by the heat we are now experiencing. Check fields regularly for the appearance of yellowing on leaves, or whitish pin-spots. Both are indications that TSSM may be present. If TSSM is present, the actual mites will be found on the lower leaf surface. It is best to treat for TSSM before the population gets too widespread. Spot treatments may be adequate to achieve satisfactory control. There are a number of good miticides available, and growers should choose products based on efficacy and pre-harvest interval. See the 2016 Commercial Vegetable Recommendations Guide for miticides effective against TSSM.
If stink bug fruit injury is increasing in harvests, or stinkbug adults, nymphs (see photo at right), or eggmasses are found in more than one of 10 samples in a field, consider treating for this pest to limit injury. See the 2016 Commercial Vegetable Recommendations Guide for insecticides effective against stinkbugs.
Pepper weevil
No weevils were trapped in the past week. As far as known, there are no infested fields.
