Question: query about fungal disease.
Answer: query about blitox @ 2ml/l of water for 3 times at 5 days interval, or apply bordeaux mixture.
bordeaux mixture (1%)

dissolve 100g of powdered copper sulphate crystals in 5 litres of water. in another 5 litres of water, prepare milk of lime with 100g of quick lime. pour the copper sulphate solution into the milk of lime slowly stirring the mixture all the while. test the mixture before use for the presence of free copper, which is harmful to the plants, by dipping a polished knife in it. if the blade shows a reddish colour due to the deposits of copper, add more lime till the blade is not stained on dipping. always use wooden, earthen or copper vessels for the preparation of bordeaux mixture.