I've been trying to figure out what is wrong with my squash. I first noticed this on my zucchini, now yellow squash, watermelons, butternut and gourds. The newest leaves are crinkled and curled up. Otherwise plants are producing, picked zucchini yesterday. Soil has clay, was low in in phosphorus, fertilized with 2-3-0 seaweed type fertilizer. Only other deficiency was boron, which I have not addressed yet. High temps have been normal (75 to 90) but lows have been about 10-15 below average (58 the other night).