Characteristics of Plant Growth Regulators (PGRs):
(i) PGRs are small, simple molecules of diverse chemical structure occurring in plants.
(ii) They are indole compounds (indole-3- acetic acid, IAA) adenine derivatives N6 - furfurylamino purine, kinetin, the derivatives of carotenoids and the fatty acids (abscisic acid, ABA); terpenes (gibberellic acid, GA3) or gases (ethylene, C2H4).
