Unseasonal showers and humid evenings have quietly set the stage for a silent invader in Punjab’s cucurbit fields. Over the past fortnight, farmers around Rajpura, Dera Bassi and Sangrur have begun spotting the tell‑tale yellow lesions of downy mildew on muskmelon, watermelon and bottle gourd crops, a fungal disease that thrives in moisture and threatens both yield and quality.Downy mildew of cucurbits is a serious fungal disease that can cause serious damage under weather conditions favourable for disease development. The disease affects foliage, producing yellow lesions on the upper surface of leaves. The under surface of these lesions show greyish fungal growth during early morning hours when there is high relative humidity. Later, such lesions turn brown and necrotic, giving a blighted appearance to the crop.“Over the last two weeks, the prevailing weather conditions have become congenial for the initiation of downy mildew in muskmelon, watermelon, bottle gourd and other cucurbit crops. Low to moderate attack of has been observed in the villages around Rajpura, Dera Bassi and Sangrur,” said Vice Chancellor, PAU, Dr Satbir Singh Gosal.According to the experts, weather conditions such as moderate temperature (25-30°C) with high relative humidity and intermittent rains help in the spread of the disease, affecting the yield and quality of the produce. So, farmers are advised to avoid flood irrigation and destroy overwintering vines to prevent this disease.“It is advised that farmers should refrain from overhead sprinkler irrigation. Irrigate cucurbit crops during day so that foliage becomes dry before nighttime. Also, for better aeration in the canopy, keep proper spacing between plants to check downy mildew disease,” add experts.PAU has tested against downy mildew of cucurbits and found Chlorothalonil (Kavach) at 400g/acre and Cymoxanil 8%+ Mancozeb 64% WP (Curzate M8) at 600 gm/acre to be effective against downy mildew of cucurbits.