Note: Cucurbit downy mildew has now been identified on cucumber in southern and northern NJ. See the pumpkin and winter squash section below for more information.
Sweet Corn
European corn borer (ECB) adults remain very low, and no map will appear in this edition.
The highest nightly trap catches of ECB for the week ending 8/12/20 are as follows:
Califon 1 | Farmingdale 1 |
Cinnaminson 1 | Medford 1 |
Downer 1 | Tabernacle 1 |
Fall armyworm (FAW) larval infestations continue, although at low to moderate levels around the state, with infestations as high as 26% in Cape May County. FAW could increase dramatically in the late summer, resulting in significant injury to whorl and even seedling stage corn. Injury from newly hatched larvae shows up as “window panes” or areas where leaf tissue has been eaten down the the lower epidermis (see photo at far left). This injury leads down into the whorl. As larvae gain size, they begin to consume leaf tissue in its’ entirety, creating ragged holes and lots of droppings (see photo at near left). FAW can be tough to manage because it is resistant to synthetic pyrethroid insecticides (IRAC 3A) and because larvae are often covered by their own droppings, making contact with the insecticide more difficult. Treat when 12% or more plants exhibit FAW injury alone, or in combination with ECB injury.
Corn earworm (CEW) moth captures are increasing gradually in blacklight traps. This moderate mid-Summer population poses a significant risk to silking corn. Catches remain somewhat variable (see map at left), with blue areas on this map representing a 4-5 day spray schedule. Note that there is disagreement between blacklight and pheromone trap maps with regard to the southwestern counties. See pheromone trap information below.
The highest nightly trap catches of CEW in black light traps for the week ending 8/12/20 are as follows:
Morristown 3 | Green Creek 2 | Farmingdale 1 |
Allamuchy 2 | Bellemeade 1 | New Egypt 1 |
Califon 2 | Downer 1 | Old Bridge 1 |
Georgetown 2 | Elm 1 | Princeton 1 |