End of the Season Powdery Mildew
Posted September 09, 2013
The first signs of powdery mildew is the white fungal growth on the leaf and vine surface. The leaves of the plants will slowly wither and die from the disease. The lack of leaf surface will reduce the photosynthetic process which is required for continued growth. Also, without enough leaf coverage, fruits are more prone to sunburn. Even when you plant resistant varieties, late season powdery fungal growth can still affect gourds, winter and summer squash. Late summer humidity can make controlling powdery mildew difficult. We plant most of our squash rather late in the season, so if they have started to develop powdery mildew while we still have two months of fruit production, by all means, we will treat the problem before it causes the fruit production to slow up and plants to wither. If our early planted vines are slowing up on their production, and there is not any new and healthy vines nearby, we simply let nature take it course. Once the plants seem exhausted and no new production of fruits is happening, we pull the plants and make room for new fall crops.
Treating powdery mildew should be done as soon as the first signs appear for the best control. Treating with a natural fungicide like tomato and vegetable fungicide, bi-carb or sulfur will do the job. Treatment may need to done weekly to get control and stop the growth of powdery mildew.
Often times you will see pumpkin fields mid September and October where the vines