Showing papers in "Philippine Journal of Crop Science in 2000"

Regulation of flowering in `carabao' mango trees by paclobutrazol

Abstract: Paclobutrazol was applied as a soil drench at concentrations of 0.5, 1.0, and 1.5 gram active ingredients per meter canopy diameter to determine its influence on flowering in 10-year-old `carabao' mango trees at BMC farm, Zambales [Philippines] last May 1998. Four months later and monthly thereafter, 10 shoots were dipped in 2% potassium nitrate to assess flowering response. Flowering started only by November or 6 months after paclobutrazol application. By December, all trees treated with 1 gram paclobutrazol per canopy diameter flowered in contrast to only 38% of the control trees. No reduction in shoot length occurred in flushes that emerged in March, 1999 except for the highest level of paclobutrazol application which indicates that the dosage of 1 gram paclobutrazol per meter of canopy diameter does not have any side effect of shortened internodes. A repeat application but at one-fourth the original rate was done on the second year. Only the highest rate was responsive indicating that there is virtually no carry-over from the previous year's application. A significant decline (32%) in GA3-like contents of shoots from paclobutrazol-treated trees became apparent two months after the soil drench. Starch content increased in stems of paclobutrazol treated trees, suggesting that paclobutrazol promotes flowering by increasing starch accumulation