The efficacy of using crop cover in controlling viral diseases of squash was studied under field conditions. Results of the study revealed that crop cover of 15 to 30 d delayed the onset of disease incidence, spread and severity of viral diseases, leading to improvement in vegetative growth and consequently, to increase and subsequent improvement in fruit yield and quality. It was observed that 21 d was the optimal coverage period for higher fruit yield. Vegetative growth and fruit yield and quality did not differ significantly for plants under cover for 15 d and 30 d.