Andy Wyenandt

Extended periods of long, hot dry weather can cause pumpkin fruit to seemingly mature quicker (i.e., turn orange). Sunscald injury occurs when cucurbit fruit are suddenly exposed to direct sunlight during the latter stages of fruit ripening during the fall. Sunscald injury often occurs after plants prematurely defoliate due to powdery mildew or downy mildew infection or when vines collapse due to Phytophthora blight or bacterial wilt.

Symptoms of sunscald injury include the collapsing of rind tissue on the side of the fruit which is in direct afternoon sunlight. Sunscald injury often develops as a pinkish-red color on exposed fruit which becomes flat in appearance. Over time fruit tissue may become tan to brown and secondary pathogens often invade the sunscald injured areas of the fruit.

To help reduce the potential for sunscald injury on pumpkin and other winter squash fruit, maintain weekly protectant fungicide programs to help retain foliage for as long as necessary, especially if fruit are going to be left in the field for long periods.

• Downy mildew remains active on all cucurbit crops. All cucurbit growers should include downy as well as powdery mildew specific fungicides in their weekly maintenance sprays. Please remember different modes-of-Action (i.e., FRAC groups) to help manage fungicide resistance develop in both pathogens. To track the progress of CDM in the US please visit http://cdm.ipmpipe.org/
• There have been no new reports of late blight in New Jersey. Remember as fall approaches and night temperatures become cooler and light fogs begin to develop conditions for late blight development improve. All abandoned tomato blocks/fields need to be disked under as soon as harvesting is done or sprayed with gramoxone to kill all living foliage. To track late blight in the US please visit http://usablight.org/
• Downy mildew was reported on turnip greens this past week. The cool, damp mornings with lingering dew have been ideal for downy mildew development across many crops.
• Basil downy mildew remains active.

Late blight has been found in a small tomato planting near Chester in Morris County. This is the third late blight report this growing season in New Jersey and the first since mid-August. Although the weather around NJ has been hot and dry the past few weeks, morning dews and fogs are slowly starting to roll in with Autumn around the corner. All tomato growers should scout their fields on a regular basis. Early-season plantings that have been abandoned need to remain on your radar screen, especially if they haven’t been mowed off or hit with gramoxone to kill all living plant material. To track late blight in the US please visit http://usablight.org/

• Downy mildew remains active on all cucurbit crops. All cucurbit growers should include downy as well as powdery mildew specific fungicides in their weekly maintenance sprays. Please remember different modes-of-Action (i.e., FRAC groups) to help manage fungicide resistance develop in both pathogens. To track the progress of CDM in the US please visit http://cdm.ipmpipe.org/
• There have been no new reports of late blight in New Jersey since 8/14. Remember as fall approaches and night temperatures become cooler and light fogs begin to develop conditions for late blight development improve. All abandoned tomato blocks/fields need to be disked under as soon as harvesting is done or sprayed with gramoxone to kill all living foliage. To track late blight in the US please visit http://usablight.org/
• Bacterial leaf spot remains active on pepper and tomato crops. Bacterial canker on tomato has also been reported.
• Pepper anthracnose has been reported. All pepper blocks/fields where anthracnose is present and harvesting is completed need to disked under and/or sprayed with gramoxone as soon as possible. Infected plant material left in the field will only serve as a source of inoculum for further spread of the disease.