European corn borer (ECB) adult activity is stable, with low level activity in parts of the state now. This is the beginning of the second adult flight. Areas of highest activity are still along the Delaware Bay Shore and in central Morris County (see ECB map), but areas between should fill in over the next week.
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 2015 Commercial Vegetable Recommendations Guide for insecticide choices.
|The highest nightly ECB catches for the previous week are as follows:|
|Centerton 2||Califon 1||Lawrenceville 1|
|Denville 2||Chester 1||Medford 1|
|Allentown 1||Downer 1||New Egypt 1|
|Belvidere 1||Georgetown 1||Woodstown 1|
Corn earworm moths (CEW) activity continues to gradually increase, mainly in the southern third of the state. Blacklight traps further north in the state have registered only scattered individuals. Overall activity is fairly low for this time of year, and is mainly from the Delaware Bay shore east to the coast in southern NJ (see CEW Map). Catches in DE are still low, and trap catches published from North Carolina have stabilized over the past week after increasing previously.
|The highest nightly CEW blacklight trap catches for the previous week are as follows:|
|Pedricktown 2||Crosswicks 1||Green Creek 1|
|Belvidere 1||Downer 1||Matawan 1|
|Cedarville 1||East Vineland 1||Woodstown 1|
|Centerton 1||Eldora 1|
The limited CEW pheromone trap network in the southern counties is also showing continued increase over the past week. Activity has shifted so that it is highest in coastal areas from the Bay Shore around to the Atlantic Coast (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, moderate silk spray schedule should be adequate to limit CEW injury as well as to prevent ear damage from ECB or FAW larvae that already inhabit the stalks.
|The highest nightly CEW pheromone trap catches for the previous week are as follows:|
|Green Creek 6||Beckett 4||Elm 1|
|Woodstown 6||East Vineland 1|
For silking sweet corn, the following spray schedules are warranted.
Silking Spray Schedules*:
South – 3-5 days
Central – 4-6 days
North – 6 days
Fall armyworm (FAW) infestations are continue throughout NJ, with infestation rates in the 30% range in coastal areas from Cape May through Monmouth counties. Lower numbers have been found inland, but FAW is present in all counties at this time. This pest can be devastating to small corn plants. Fields down to seedling stage should be scouted weekly for signs of infestation. 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 2015 Commercial Vegetable Recommendations Guide for insecticides effective against FAW.
Late blight has not been found since the initial infections of two weeks ago, and recent hot weather has not been conducive for spread of this disease. However, tomato growers should continue to protect all plantings against this disease. The strain found locally is US-23, and can infect tomatoes and potatoes, although no infections on potatoes have yet been reported. Consult the 2015 Commercial Vegetable Recommendations Guide for fungicides effective against late blight.
The return of ECB adults in our area is a reminder that this pest can cause injury to pepper fruit. As local blacklight trap catches reach or exceed 1 moth/night, growers should consider their peppers to be at risk of infestation. Several options exist for control, including soil (drip) applied IRAC group 2i materials like Coragen or foliar applications of IRAC group 5 materials like Radiant or the OMRI approved version, Entrust. See the 2015 Commercial Vegetable Recommendations Guide for insecticides effective against ECB.
Pepper Weevil Report
No weevils have been trapped in the past week and as far as known, there are no infested fields.
Brown Marmorated Stink Bug (BMSB)
BMSB numbers remained low in NJ blacklight traps this past week, with continued higher activity in one trap in Cape May County. These catches are too low to create a map. As yet, no fruit injury has been discovered in scouted pepper plantings.
|The highest nightly BMSB blacklight trap catches for the previous week are as follows:|
|Green Creek 8||Cinnaminson 1|
|Woodstown 3||Pedricktown 1|
|Centerton 2||Princeton 1|
Pumpkins and Winter Squash
Cucurbit downy mildew (CDM) is active on butternut squash, pumpkin and cucumber in northern NJ, and is likely to be present in all areas of the state. As yet, acorn squash, watermelon and muskmelons are uninfected in the sentinel plot at the Snyder Research and Extension Farm in Hunterdon County. For more information on the regional presence of DM as well as comprehensive, weekly forecasts, see the following website: http://cdm.ipmpipe.org/ Growers should consider applying both protectant and systemic fungicides to all cucurbit crops at this time, to limit loss from this disease.
Additionally, early pumpkin fields are now showing signs of powdery mildew (PM) infection. Protectant fungicides are warranted on any fields where PM lesions are now occurring. PM does not typically occur until the host crop enters the stage of fruit enlargement. Consult the 2015 Commercial Vegetable Recommendations Guide for fungicides effective against CDM and PM.
Basil downy mildew (BDM) has been reported from all parts of NJ, and the BDM sentinel plot at the Snyder Research and Extension farm is now infected as well. Growers apply appropriate fungicides to manage this disease on all sweet basil types.
The following is an excerpt from Dr. Andy Wyenandt’s post of 6/13/14:
All sweet basils are susceptible to the disease. Lemon/Lime and Spice-type basils show much greater tolerance/resistance to basil downy mildew. Control of basil downy mildew begins with planting resistant-types (when possible) and preventative fungicide applications BEFORE basil downy mildew appears on your farm. Weekly applications of a phosphite fungicide (FRAC code 33) such as K-Phite, Pro-Phyt, Rampart or other labeled phosphite at a high rate will help suppress basil downy mildew development. Ranman (cyazofamid, 21) at 2.75 to 3.0 fl. oz/A and Revus (mandipropamid, 40) at 8.0 fl. oz/A now have labels and will also help to suppress basil downy mildew development. These fungicides should be used in rotation with each other and included in a tank mix with a phosphite fungicide on a weekly basis. Our research has shown that if fungicide applications are started AFTER the pathogen has been found in the field will often result in very poor season-long control.
Options for organic growers are limited. Our research has shown that most products only offer some suppression as long as disease pressure remains low. Avoid overhead irrigation if possible, increase plant spacing to improve airflow to help leaves remain dry, and always plant basil in a sunny location.
NOTE: Maps will not appear in next week’s edition of the Vegetable IPM Update, but will resume on 8/12/15. Updates to the sweet corn silk spray schedule as well as other significant pest information will appear in the 8/05/15 edition.