When used as a plant growth stimulant in agriculture, 1-Naphthylacetic acid has the characteristics and physiological functions of the endogenous auxin IAA. It promotes the metabolism and photosynthesis of crops, such as promoting cell division and expansion, inducing unstable root formation, increasing fruit setting, preventing fruit dropping, and changing the ratio of male and female flowers, etc. At higher concentrations, it has the effect of inhibiting growth. Soaking rice seedlings and wheat seeds in NAA solution can increase yield. It can also prevent the dropping of fruit trees and cotton, promote the plant cuttings rooting and flowering, increase the germination rate, and make crops mature and productive. Prevents falling of flowers and fruit and promote formation of seedless fruits.

 When used in preventing fruit falling, the concentration should not be too high, otherwise it will have the opposite effect, because the high concentration of 1-naphthylacetic acid can promote the production of ethylene in plants;

When used in promoting plant root, it will be better to combine with IAA or other root-promoting agents, if only use 1-naphthylacetic acid, crop rooting effect is good, but the seedling growth is not ideal. When spraying melons and fruits, it is advisable to spray evenly on the leaves.