Reproductive and morphological phenology of eight Mexican cacao clones (Theobroma cacao L.)

Abstract

Objective: To describe the dynamics of floral biology and fruit development until physiological maturity, by performing a qualitative and quantitative characterization in eight Mexican cacao clones (Theobroma cacao L.), called: Caehui, Chak, Canek, Chibolon, Supremo, Tabscoob, K'in and Olmeca. Design/methodology/approach: In the phenological study, five trees were taken into account and five flower buds per tree were randomly identified (n=225). Twenty-one (21) qualitative and quantitative morphological descriptors were evaluated in fruits and grains. Descriptive statistics were established and a principal component analysis was applied to the quantitative descriptors. Results: The Chak clone presented the highest value for length and diameter of flowers buds in reproductive phenology, with 7.4 mm and 4.2 mm; the K ́in clone stood out in fruits, with 252 mm length; and Supremo in fruit diameter, with 102 mm. Significant differences were found in the morphological variables evaluated, in addition to significant positive correlation (p<0.05 and p<0.001) between most of the variables. The first two main components described 62.5% of the total variation. Findings/conclusions: The differences in measurements (length and diameter) of the flower buds are attributable to the genetic constitution; however, knowing the opening times allows us to have an exact reference in production levels. The parameters that contributed most to the variability observed were weight and diameter of the fruit, length and width of the grain, thickness of the exocarp, and weight of grains per pod.