This upward Curl is due to insect feeding.
These insects are called “thrips”.
Look the moving thrips in this vedio.
Don't worry. You can adopt the following methods to manage the thrips. There are two ways to manage thrips
First is, you have to spray chemicals, either Imidacloprid or Reagent @5ml/lit with a freqency of once in 5 days, if the leaf curl is clearing dont spray the chemical.But these chemicals are hazardous to other organisms too. So I suggest another methods other than chemicals
* Here are the Steps for the Preparation of the Bio-pesticides
- Take cow urine + cow dung in 3:1 ratio
- This mixture should be kept for 2 months in a container with open mouth
- You can spray this mixture diluting five times with water
If you adopt some simple agronomic practices then you can minimise the infection in your field.