Author : Thanda Aye

Summary : A trunk injection technique is a feasible alternative of applying flower inducers in mango trees. Injecting four ml of paclobutrazol (25% SC at 1 g a.i. per meter canopy) in two 4mm holes (bored at 45 angle, 2.5 cm depth) to 4-5 year old 'Carabao" mango trees grown in polybags resulted to shorter shoot length and wavy leaves, indicating uptake of the compound. Injecting 2ml of Ethrel (48% SC), four months later resulted in 70% flowering, compared to the Ethrel-sprayed trees with 5% and water-injected control with 0%. Starch and nitrogen levels in the leaf tissues of treated trees were low. Morphoanatomical study confirmed the efficiency of trunk injection as a feasible alternative to spraying of Ethrel in mango. Spraying of alternative bud break agents in paclobutrazol treated trees showed that nitrogen-based compounds (Ca(NO3)2, NH4NO3, and NaNO3) induced 22-50% flowering compared to 10-12.5% flowering from potassium-based compounds (K2SO4, and KCl). Control trees gave no response. The positive control, KNO3, which exhibited 77.5% flowering, is still the best bud-break agent for mango.