advice regarding moldy and curly leaves

[OpenField]

Hi there,

Every year I have a very good harvest of zucchini, however around this month I get moldy (white dust on top) and curly spotted leaves. I believe the reason could be bad ventilation and lack of soil nutrients (too much fruit production exhausting the soil).

Do you have any better explanation for this problem?.

[jack oostenbrink]

This is pretty common on squashes and usually sets on in August. The fungus is powdery mildew and it does well in hot and humid conditions. To slow the onset of the mildew, avoid watering the leaves, or at least water in the morning when they can dry out quickly. You could also thin out some of the leaves to allow more air cirulation around them. It doesn't really affect the quality of squash that gets produced, though a very bad mildew outbreak can reduce photosynthesis and weaken the plant.