BioQuest | Vol. 1, No. 1 (July 2017) 12 Introduction Plant growth regulators or phytohormones are organic substances produced naturally in higher plants, controlling growth or other physiological functions at a site remote from its place of production and active in minute amounts. Plant growth regulators include auxins, gibberellins, cytokinins, ethylene, growth retardants and growth inhibitors. Large number of plants are propagated by stem cutting, leaf cutting and layering. For promoting rooting, the commonly used hormone is IBA followed by NAA. IBA enhances root formation on cuttings. Cytokinins also help in quick and profuse root formation on cutting and layers. By use of IBA, profuse root formation is observed in cutting at pomegranate, grape etc. Seed Germination Plant growth regulators are used to promote early seed germination and improve the germination percentage. Many seeds have natural dormancy which can be overcome by dipping the seeds in auxins. GA3 @ 500 ppm solution enhances seed germination in aonla Ber- 500 ppm GA 200 ppm GA + 5% Sucrose. Vegetative Propagation a. Cutting: Auxins play an important role in the initiation of roots in cuttings. Guava cuttings: 5000 ppm IBA by quick dip method Grape cuttings:4000 ppm IBA by quick dip method Pomegranates: 2000 ppm IBA by quick dip method Litchi cuttings: 3000 ppm IBA by quick dip method Jamun cuttings: 5000 ppm IBA by quick dip method Fig cuttings: 1000 ppm IBA by quick dip method Air layering-guava: 3000 ppm IBA by pasting lanoline paste Air layering-pomegranate: 3000 ppm IBA by pasting lanoline paste Air layering-litchi: 5000 ppm IBA by pasting lanoline paste Air layering-jamun: 10000 ppm IBA by pasting lanoline paste Air layering-tamarind: 4000 ppm IBA by pasting lanoline paste Air layering-cashew: 500 ppm IBA by pasting lanoline paste Fig: Air Layering in Guava b. Layering: Paste of auxin pasted on the operated portion of the plant part helps in initiation of roots in grafting and layering e.g. Air layering in Guava. Importance of plant growth regulators on fruit nursery Subbaiah KV 1 *, Raju GS 1 , Nirmala TV 1 , Reddy AD 1 , Karuna Sree E 1 , Reddy RVSK 2 1 Krishi Vigyan Kendra, DrYSR Horticultural University, Andhra Pradesh, India 2 Administrative Building, Dr YSR Horticultural University, Andhra Pradesh, India *Corresponding author email: [email protected]