Effect of thiourea on terminal bud break of mango.
Tongumpai P., Charnwichit S., Srisuchon S., Subhadrabandhu S.
Author Affiliation: Department of Horticulture, Kasetsart University, Bangkok, Thailand.
: 71-75
Abstract : Three-year-old mango trees of the cultivar Nam Dok Mai were treated with thiourea to induce bud break. Thiourea was sprayed on to fully expanded leaves at 0.5 and 1% until run-off. Treated trees produced uniform terminal bud breaks 14-16 days after treatment, while bud break in the controls occurred at 31 days. When 1% thiourea was applied, severe defoliation occurred. The phenology of new shoots produced by all treatments was similar. Three-year-old mango trees of the cultivar Khiew Sawoey were also treated with 0.5% thiourea. After this treatment, new shoot growth occurred within 14 days. To induce flowering, the trees were drenched with 6 g paclobutrazol/tree, and were then treated with 0.5% thiourea at 45, 60, 75, 90, 105 or 120 days after paclobutrazol treatment. Bud break was low in the 45- and 75-day treatments. In the 90-day treatment buds were entirely vegetative, but in the in the 105- and 120-day treatments, 80 and 100%, respectively, of buds breaking were flower buds. It is suggested that flower initiation induced by paclobutrazol was completed after 90 days.