HomeInternational Rice Research Notesvol. 22 no. 2 (1997)

Growth Response of Diverse Rice Genotypes to Exogenous Application of GA 3

S Singh | T Ram

Discipline: Agriculture



Although exogenous gibberellin (GA) usually breaks dwarfism, some cereal genotypes do not respond because they have a higher level of endogenous GA. This study examined the growth response to exogenous GA of rice genotypes with different statures and sources of dwarfism. The rice genotypes included a Dwarf mutant (superdwarf), dwarf Cigar, Nadula dwarf (semidwarf), Dee-geo-woo-gen (semidwarf), and C14-8 (tall). Seedlings (25 d old) were transplanted separately in the ricefield at 40- × 20-cm spacing during the wet season. A full dose of NPK was applied before transplanting (during puddling). Two rows of each genotype were fully sprayed with 100 ppm of GA 3 at 20 and 45 d after planting. Morphological and growth characters were recorded at heading, and dry weights of plant parts were recorded after drying the plant samples in a hot air oven at 70 °C for 72 h.