Leaf-curl is a plant viral disease. Chilli plant gets it more often. Since fundamental of sickness in Ayurvedic perspective is different from other methods, solution is also different.
Viral infection is a cellular stress. Idiots spray fungicide to control fungus. But we do it differently.
Due to untimely rain last year, we got this in home garden and several farmer friends got it @ farms.
We spray butter milk prepared from desi Gau raw milk.
Butter milk helps plant to induce innate immune responses and get stabilized against stress (here environmental variation stress).
The amino acid proline has been found to systemically induce resistance in plants. It stimulates production of antimicrobial phenolics. High amounts of endogenous proline increase contents of cytokinins and auxins.
Besides, holistic view of organism suggest that viral sickness is due to stress. Stress can be reduced when you instill more Prana. Manual churning of milk induce prana in it. Call it probiotic bacteria if you want.
Zero budget recovery! Unlike popular mainstream destructive, ineffective fungicide solution!
Spreader-stickers, or if you prefer, sticker-spreaders, are agents we can add to garden sprays to make them more effective. Sticker / Spreaders are products that you mix in a sprayer tank with insecticides, fungicides or foliar fertilizers to the product stick to the plant you are spraying and also disperse evenly over your plants. Many sticker / spreaders will help reduce drifting where most of your product blows away with the wind and many have waterproofing and anti-evaporation properties.
To ensure you get the full value out of your insecticides and fertilizers it is a good idea to use a sticker / spreader in every single tank.
First you buy costly chemicals and then buy supporting chemicals to increase their efficiency! 
😀
We use zero budget solution.
Butter milk or milk is great Spreader-stickers + Immune booster for all plants. 
🙂 Zero cost, healthy plants, great yield!
