Cotton squares and small bolls dropping off before opening, what is causing it?

Heavy shedding of squares, flowers and young bolls without many caterpillars usually has more than one cause, so check before spraying. Cotton naturally sheds some fruiting bodies, but heavy drop is often from stress, cloudy low light weather, waterlogging or moisture stress, and too much nitrogen that pushes vegetative growth over fruiting. Balance your fertiliser, avoid excess urea, ensure good drainage and even moisture, and a recommended foliar nutrient or plant growth support spray at squaring can help retention. Still, rule out pests, so open a few shed squares and bolls and look for tiny pink bollworm larvae, exit holes or sucking pest damage, and check for jassids and thrips on the leaves. If you find larvae inside shed structures, treat for the borer as recommended. If the shedding is clean with no larvae, treat it as a stress and nutrition issue. Confirm the cause with your KVK or PJTSAU by examining shed bolls.