The light-colored discoloration on these zucchini plant leaves is known as Squash Silverleaf Disorder (SSL) and is the result of immature whiteflies feeding on the squash leaves. SSL reduces the plant’s ability to photosynthesize, leading to stunting and reduced yields.
Whiteflies can become significant pests in numerous crops in SC, particularly in the lower coastal plain. Populations also tend to be higher near cotton fields.
Read more on hgic.clemson.edu