Monsoon Vegetable Garden Guide: Common Pests & Diseases in Nepal

Downy Mildew in Cucumber and Pumpkin

Downy mildew pressure climbs fast in cucumber and pumpkin crops once the monsoon sets in. As soon as you spot it, spray a mix of Mancozeb 64% + Metalaxyl 8% at 2g per litre of water, soaking the whole plant, repeated every 10 days for up to three rounds.

Fruit Borer in Tomato, Brinjal & Chili

Set up pheromone (TLM lure) traps in an ota-ti design with soapy water and 5 drops of oil to monitor fruit borer activity in tomato fields. Collect and destroy any damaged leaves, shoots, and fruit. If the infestation is heavy, spray Chlorantraniliprole (18.5% SC) at 1ml or Spinosad (45% SC) at 1ml per 3 litres of water, repeating 2–3 times at 12–15 day intervals. Rotate between different pesticides rather than using the same one repeatedly — pests build resistance quickly to a single active ingredient.

Damping-Off in Vegetable Nurseries

To control damping-off (seedling rot) in brinjal, chili, and tomato nurseries, drench the soil with a solution of Trichoderma harzianum at 5g per litre of water.

Foot Rot and Wilting in Chili Plants

If plants are wilting and dying from foot rot, drench each plant's base with copper oxychloride (2g per litre of water), soaking the root collar area thoroughly, and repeat 4–5 times at 10-day intervals.

Feeding Fruiting Vegetables for Bigger Yields

Crops like tomato, brinjal, and chili demand heavy nutrients once fruiting begins. Top-dress with 10g urea per plant every 15–20 days after you start harvesting, and spray a micronutrient solution at 3ml per litre of water — this consistently improves both fruit size and count.