The plant growth regulators (PGRs) are the organic chemical compounds, which modify or regulate physiological processes in an appreciable measure in the plant when used in small concentration and mediate responses to both biotic and abiotic stresses. These compounds either imitate hormonal substances by structural similarity or act by interfering with the biosynthesis, translocation or metabolism of the phytohormones. These chemicals are specific in their action. They increase flower bud formation, inhibits flower bud formation, thinning by promotion of fruit/flower abscission, retards pre-harvest drop, improved fruit finish, improved fruit shape, vegetative growth control, increases fruit set, increases fruit red colour, advance fruit ripening, delays fruit ripening, enhanced rooting, suppresses growth of water sprouts, improved stress tolerance. Use of PBRs is a unique fact of biotechnology and a new approach of manipulating plant biological activities for enhancing growth, yield, quality, nutritive value and also to reduce biotic and abiotic stress in plants. Thus, plant growth regulator is necessary for efficient horticultural crops production with respect to growth, yield and quality.