Potential regulatory role of gibberellic acid on sprouting and early stalk growth of sugarcane

Effect of gibberellic acid (GA_3) on growth characteristics and biochemical attributes of sugarcane plants using single bud setts was studied under tray culture conditions Single bud setts of sugarcane (Saccharum spp.hybrid) cultivar CoSe 92423 were soaked in graded concentration of GA3 solutions (10,20,50 and 100 mg·L~(-1)GA_3) along with water soaked control for 24 h.Treated setts were planted in soil tray culture and maintained under net house conditions.Lower levels of GA3 (10,20 and 50 mg· L~(-1)GA_3) showed stimulatory effects on bud sprouting and growth attributes viz.,root number,fresh weight of root,leaf and shoot,leaf area and shoot height.Compared to control (70%),GA_3 treatment showed early and higher rate of bud sprouting; maximum sprouting (90%) was recorded at 50 mg·L~(-1)GA_3 level.Increase in plant height and shoot weight ranged from 90 to 110% and 252 to 282%,respectively; maximum improvement was recorded at 20 mg·L~(-1)GA_3 level.Reducing sugars and IAA contents in sprouted buds increased due to GA3 treatment,and recorded highest at 20 mg·L~(-1)GA_3.Results obtained indicated stimulatory effect of lower levels of GA3 (10,20,50 mg·L~(-1)) on bud sprouting and growth attributes while higher level showed inhibitory effect on sugarcane growth.