Phenology, production and starch content of mango trees in Guanacaste, Costa Rica

The objective of this work was to determine the seasonal variation of the starch content of mango trees and its relationships to phenology and fruit production. Trees of Tommy Atkins (TA) and Keitt (K) varieties were studied in Guanacaste, Costa Rica. The phenological stages recorded were: (1) appearance of vegetative buds, (2) flowering, and (3) fruit production. The latter represented the total weight of fruits per tree. Starch content was determined through enzymatic hydrolysis of wood from roots, trunks and branches for four phenological stages during 2004 and 2005. Temperature and precipitation was also recorded. Starch content varied throughout the study, and was influenced by flower and fruit production, with the highest concentration (TA: 11,7%, K: 14.4%) just before flowering (between August and November). The lowest concentration of starch (6.1%) was recorded at postharvest for both varieties (May). The Tommy Atkins variety had the highest production in 2006 with 208,5 kg/tree and the lowest production in 2005 with 34.9 kg. In contrast, peak production occurred in the Keitt variety in 2005 with 212.1 kg, and the lowest in 2004 with 36.7 kg/tree. The highest harvest in both varieties could be assigned to "on" years and the lowest to "off" years, while 2004 in Tommy Atkins could be considered an intermediate harvest of 86.7 kg/tree.