Understanding plant growth regulators, their interplay: For nursery establishment in fruits

Abstract

The term plant growth regulator (PGR) includes naturally occurring plant growth substances or phytohormones, as well as synthetic compounds which mostly are chemical analogs, materials that alter hormone levels (hormone releasing agents or synthesis inhibitors) and materials that alter hormone sensitivity. The concentrations of hormones required for plant responses are very low (10-6 to 10-5 mol/l). Because of these low concentrations, it has been very difficult to study plant hormones and only since the late 1970’s have scientists been able to start piercing together their effects and relationships to plant physiology. Since the 1940’s both natural and synthetic growth regulators have been used in agriculture and horticulture with increasing incidence to modify crop plants by controlling plant developmental processes, from germination to post harvest preservation. The concentrations, time and method of applications play an important role in determining the effect of these chemicals on varied fruit crops. Plant growth regulators have a great use for nursery growers from storage of planting material to branch initiation. As, quality planting material is a paramount concern of the researchers and fruit grower’s for better growth and yield of plants. Exogenously applied GA3 overcomes seed dormancy in several species and promotes germination in some species that normally require cold stratification, light, or after-ripening. Plant bio-regulators helps in formation of good architecture which will enhance better quality production, better utilization of land and are known to develop higher number of branches, higher leaf area and better ratio between tiny roots and skeletal ones.