The ashen powdery stuff on gourd leaves is most likely a fungal disease known as powdery mildew. Here are some ways to protect your gourds from this problem:
Choose Resistant Varieties: Choose gourd varieties that are resistant to powdery mildew. Consult with a gardening expert or seed vendor to find resistant varieties in your region.
Proper Plant Spacing: Proper spacing between plants can help improve air circulation around the plants, which reduces humidity and the likelihood of powdery mildew.
Monitor Watering: Overwatering or underwatering can contribute to powdery mildew, so monitor soil moisture levels and water your gourds appropriately. Water your plants early in the morning so the leaves have time to dry before the evening.
Remove Infected Leaves: If you spot any leaves with powdery mildew, remove them immediately and dispose of them in the trash. This can prevent the spread of the disease to other leaves.
Fungicides: If the above steps are not sufficient, you can also consider applying a fungicide. Consult with a gardening expert or a local nursery to find an appropriate fungicide for your gourds and follow the instructions carefully.
Remember, prevention is always better than cure. Therefore, regular monitoring and proper maintenance of your gourd plants can help prevent powdery mildew from occurring in the first place.