Physiological and growth responses of mango (Mangifera indica L.) to methanol and potassium nitrate application.
Shongwe V., Roberts-Nkrumah L. B.
Author Affiliation: Department of Crop Science, University of the West Indies, St. Augustine, Trinidad and Tobago.
: 64-70
Abstract : During 1993, the effects of 'off-season' applications of KNO3 (6%) and methanol (50%) on the flowering of mangoes were investigated in plants potted in a 1:1:1 loam:clay:sand soil mixture in the greenhouse. Three-year-old potted plants of Julie, a semi-dwarf cultivar, and Graham and Tommy Atkins, 2 vigorous cultivars, were sprayed with KNO3 or methanol in May or June. New shoots on methanol-treated Graham and Tommy Atkins plants were significantly longer than those on controls (sprayed with water). Julie flowered in June and in August, and produced more panicles in response to KNO3 treatment than the controls. Methanol-treated Julie plants produced fewer and smaller panicles, especially with the first application. Graham and Tommy Atkins flowered in September to October, with panicle number and size responses similar to those of Julie, although the first methanol application increased flower number in Graham. The first methanol application and the second KNO3 application significantly lowered transpiration rate in Julie. The other cultivars responded similarly with the second application of both chemicals. Both chemicals produced higher water use efficiency (WUE) in Julie. It is suggested that the ability of KNO3 and methanol to affect flowering is related to their relative effect on WUE.