Why thrips need a schedule, not a reaction
Thrips damage in chilli is cumulative. By the time leaf curl is visible across the field, the feeding that caused it happened ten to fourteen days earlier. A reactive spray at that point protects the next flush, not the one already curled.
The growers who hold grade through the season scout twice a week from transplanting and spray on threshold, not on symptom. The threshold commonly used is an average of 5 or more thrips per leaf on the top three leaves.
A working schedule
Weeks 1–3 after transplanting: scout only. Healthy transplants with balanced nutrition tolerate low thrips numbers. Avoid unnecessary early sprays that remove natural enemies.
Weeks 4–8 (vegetative to first flowering): at threshold, apply a targeted thrips product such as Spinosad 45% SC at 75 ml per acre. This is the window where control protects flower set.
Weeks 8 onwards (flowering and fruiting): rotate to a different mode of action on each subsequent spray. Never repeat the same active twice in a row — resistance in thrips builds within a season.
Rotation and resistance
Keep at least three modes of action in the season plan and rotate them in sequence. Record what was sprayed and when — a written schedule is the cheapest resistance-management tool available.
Water volume matters as much as the product. Thrips shelter in flowers and growing tips; use at least 200 litres per acre and a fine droplet to reach them.
Note
Doses stated are indicative label rates. Always confirm against the product label for your crop and region before spraying. Use agrochemicals responsibly. Read the label before use.