Pods Filling in Natural Pollination of 10 Spontaneous Cocoa Trees from French Guiana

Abstract

The study focuses on the filling of pods from ten cacao clones originating from French Guiana in Côte d’Ivoire. Two reference clones (IFC5 and NA32) were used as controls. The parameters studied include the number of ovules per ovary, the average number of beans per pod, the fresh bean weight, and the pod index. The aim was to evaluate the genetic variability and agronomic performance of these clones under natural pollination conditions. The results show significant genetic variability between the clones for all traits studied. The IFC5 clone, known for its excellent pod filling, exhibited the highest apparent fertility (0.91), while the GU183/A clone had the lowest filling (0.47). Three types of distributions of the number of beans per pod were identified: a right-skewed unimodal distribution, characteristic of well-filled clones; a left-skewed unimodal distribution, associated with poorly filled clones; and an intermediate bimodal distribution. These differences could be related to pollination compatibility and the availability of compatible pollen. Regarding the fresh bean weight and pod index, the GU183/A clone stood out with the heaviest beans (3.27 g) but had a high pod index (49.58), indicating relatively low productivity. None of the Guyanese clones achieved the filling level of the IFC5 clone, although some surpassed the NA32 control. This study highlights the importance of apparent fertility and the number of beans per pod as essential criteria for cacao genetic improvement programs. The authors recommend extending research to a larger number of Guyanese clones and exploring complementary traits, such as the influence of pollination type and intergroup compatibility.