Plant Growth Regulators: Plant hormones (also known as plant growth regulators (PGRs) and phytohormones) are chemicals that regulate a plant's growth. Plant hormones on the other hand, are not like animal hormones, they are often not transported to other parts of the plant and production is not limited to specific locations. Plants lack tissues or organs specifically for the production of hormones; unlike animals, plants lack glands that produce and secrete hormones to be moved around the body. Plant hormones shape the plant, effecting seed growth, time of flowering, the sex of flowers, its longevity, senescence of leaves and fruits, they affect which tissues grow up and which grow downward, leaf formation and stem growth, fruit development and ripening, and even plant death. Hormones are vital to plant growth and lacking them plants would be mostly a mass of undifferentiated cells. Hormones: In plants, many behavioral patterns and functions are controlled by hormones. These are “chemical messengers” influencing many patterns of plant development. ¡ Plant hormones – a natural substance (produced by plant) that acts to control plant activities. Chemical messengers. ¡ Growth Regulators ¡ Plant growth regulators – include plant hormones (natural & synthetic), but also include non-nutrient chemicals not found naturally in plants that when applied to plants, influence their growth and development. ¡ 5 recognized groups of natural plant hormones and growth regulators. 1. Auxins 2. Gibberellins 3. Cytokinins 4. Ethylene 5. Abscisic acid Cortesy: Amit Bhaskar Got something to say about this post? Leave a comment...your comments are valuable for improving the posts.