My sunflower heads are being eaten by caterpillars and some plants show black necrotic patches. How do I manage these problems?
How do I control sunflower head borer and necrosis disease (sunflower)?
SShekhar Goud5mo ago · 234 views
5 Answers
🌾Farmer.in Krishi TeamExpert ✓5mo ago
Head borer caterpillars feed on the developing seeds in the head and can cause heavy loss, while sunflower necrosis is a virus disease spread by thrips that shows as black necrotic patches and distorted growth, so the two need different handling. For head borer, scout heads from flowering, use pheromone traps and bird perches, and apply a need based insecticide directed at the head when small larvae are present, following the label and PHI. For necrosis, since it is viral there is no cure, so control the thrips vector, rogue out early infected plants, and use clean recommended seed and timely sowing to escape peak thrips. Avoid spraying during peak bee activity to protect pollination. Get the current borer and thrips management schedule from your local KVK.
MMahantesh5mo ago
Timely sowing along with my neighbours helped me dodge the worst of the thrips and the necrosis. When my crop flowered out of step with the thrips peak there was much less of the black patchy disease. Staggered late sowing kept getting hit, so sowing on time matters for necrosis.
NNingappa Goud5mo ago
For the head borer I scout the heads from flowering and put up bird perches, and the birds take a good share of the caterpillars. When I do need to spray I direct it at the head while the larvae are still small, not after they are buried in the seeds. Follow the label and the PHI on the product.
VVeeresh Kumar4mo ago
Remember the necrosis cannot be cured once a plant has it, so pulling out the early infected plants the moment you spot the black patches stops it spreading. Clean recommended seed to start with and controlling the thrips are the real defence. Do not waste money spraying the diseased plants hoping to recover them.
BBasanagouda4mo ago
Avoiding the spray during peak bee hours was something I had to learn, because the head needs the bees for filling and a wrongly timed spray for the borer was knocking out my pollinators. I spray late in the evening when the bees are off the field and direct it at the head for the small larvae. That way I protect the seed set and still manage the borer.