PACLOBUTRAZOL AND ITS IMPACT ON GROWTH AND PHYSIOLOGY IN VARIOUS CROPS : A REVIEW

Abstract

Growth retardants are essential tools in modern agriculture and horticulture, helping regulate excessivevegetative growth, improve crop yield, enhance stress tolerance and optimize overall plant quality.Paclobutrazol (PBZ) is among the most extensively utilized synthetic growth retardants, recognized forits ability to regulate plant growth without interfering with developmental processes or causingphytotoxicity. This compound is chemically described as β-(4-chlorophenyl)methyl-α-(tert-butyl)-1H1,2,4-triazole-1-ethanol. PBZ suppresses gibberellin biosynthesis by inhibiting the transformation of entkaurene into ent-kaurenoic acid leads to a significant reduction in shoot elongation. Moreover, Itregulates the signaling pathways of other plant hormones, including cytokinins and abscisic acid, therebyfurther influencing plant growth and development. Paclobutrazol has been extensively studied for itsdiverse applications across various crops. In fruit crops, it restricts excessive vegetative growth, inducesearly flowering, enhances fruit set, manages biennial bearing and facilitates high-density plantingsystems. In vegetable and field crops, it reduces plant height, increases stress tolerance, enhanceschlorophyll content, prevents lodging, minimizes disease incidence and improves seed yield and quality.In floricultural crops, it is primarily used for height control and increased plant compactness as well asenhancing their ornamental value. Given its wide-ranging benefits, paclobutrazol has emerged as avaluable growth regulator for improving plant architecture, productivity and stress resilience. However,its precise application rates and effects vary depending on crop species, environmental conditions andagronomic practices. This review compiles and analyzes research findings on the impact of paclobutrazolacross multiple crop species, highlighting its role in sustainable agriculture and efficient cropmanagement.