Auxin is an important plant hormone that regulates fruit set, growth and development in horticultural crops. It promotes fruit set by preventing flower and young fruit drop after fertilization. Auxin enhances cell division and cell enlargement, leading to improved fruit size and uniform growth. Exogenous application of auxins can induce parthenocarpy and increase yield in several fruit crops. Proper dose and timing of auxin application are essential for achieving better fruit quality and productivity.