Late blight hits my potato crop suddenly in foggy weather. How can I use forecasts to spray before it spreads?
How do I use late blight forecasting and weather alerts for potato (aloo) in West Bengal?
SSubhankar Das7mo ago · 311 views
5 Answers
🌾Farmer.in Krishi TeamExpert ✓7mo ago
Late blight explodes in cool, cloudy, humid weather with fog and dew, so the trick is to spray protectively before the weather turns, not after you see lesions. Watch agromet advisories and late blight warnings issued by ICAR-CPRI and your state agriculture department and KVK during the potato season, as they track the conducive weather windows. When a warning or such weather is forecast, apply a protectant fungicide like mancozeb on the standing crop ahead of time, and switch to a recommended systemic or combination product once the disease appears, rotating chemistry to avoid resistance. Remove and destroy infected plants and volunteer potatoes. Always follow the product label dose, waiting period and your KVK advice rather than fixed doses, because correct timing matters more than the chemical you pick.
NNemai Mondal7mo ago
In our area once the fog sets in for a few days the blight is unstoppable if you waited. I now spray protectant the moment the forecast shows that cool damp spell.
GGobinda Santra6mo ago
I keep my phone alerts on for the state agromet advisory and also just watch my own field at dawn for dew that does not dry till late morning, which is the danger sign here. A group of us in the village share the forecast and spray together, because if one field is left untreated it feeds the rest.
AAsit Bagchi6mo ago
A caution on resistance, do not keep using the same systemic spray after spray. One year I leaned on one product and it stopped working mid season. Starting with a protectant before the weather turns and rotating the systemic groups as KVK advised held the disease far better.
SSandhya Mondal6mo ago
Pulling out and destroying the first few infected plants slowed the spread in my field. Once a plant is hit it throws spores onto the rest, so I do not leave the rotting plants standing. I also clear out volunteer potatoes from the last crop because they carry the disease over.