It is time to watch for powdery mildew. Reports of powdery mildew on pumpkin and summer squash have come in from Berkshire and Norfolk Counties in Mass. However I have not yet in Maine. Look for whitish or grayish talcum-like fungal growth on the upper or lower surface of the leaves and on petioles and stems. Check 5 mid- or lower leaves at 10 locations in the field.
Symptoms usually develop first on older leaves.
Older plants will show it first. It can often be found on summer squash before it develops on winter squash or pumpkin. Fungicide applications should begin if powdery mildew is found on one leaf out of 50 anywhere in the field. Even hoop house tomatoes are behind although they are being harvest now. Field tomatoes look like August this year.