Cool temperature and excessive nitrogen may also be related to this problem. Usually the problem is temporary and will be resolved when lateral vines develop to produce female blooms with normal frequency. Such areas occur regularly in early spring and fall when the humidity is low. These areas are caused by wind-blown sand, leaves rubbing together, or both. This abrasive action ruptures the leaf tissue causing the plant sap to evaporate and the tissue to die.
Young fruits turn brown and shed.
This condition is usually caused by lack of pollination brought on by inadequate numbers of bees, excessively hot and dry conditions, and, in some cases, plant diseases. Meandering paths or trails on leaf surface. They are rarely a serious problem. With care, the very small brownish larvae can be lifted out with the point of a knife. Leafminer injury is sometimes a point of entry for disease-producing organisms.