Question: query regarding how to improve the growth of the chilli plant.
Answer:  observed the root portion by uprooting the the plants. if any damage have seen then discard the seedlings and replant again. 

after that apply potash 6 gram/liter of water near the root zone by loosening the soil. with the help of khurpi.

sprays vitamins like -biovita/ mohaphol/ sagorika 2ml /liter of water @15 days interval in the evening time and to be continue up to the season end.