Structure and Stability of Cocoa Flowers and Their Response to Pollination

Abstract

This study investigated the position of staminodes around the style of cocoa flowers and the stability of cocoa flowers relative to pollination and seasonality. Cocoa flowers were categorized into converging, ≤1.20 mm; parallel, 1.21–2.40 mm, and splay ≥2.41 mm, depending on the distance between the staminode and style. Some flowers were hand pollinated while others were not and were excluded from insect visitors. Proportions of flowers of converging (56.0%), parallel (37.5%), and splay (6.5%) remained similar along the vertical plane of cocoa trees. Although pollination rates of flowers with splay staminodes were the lowest, the overall pollination success of cocoa trees was not significantly affected because of the small proportion of splay flowers.The stability of the cocoa flowers depended on both the season and pollination. During the dry season, unpollinated flowers of cocoa trees showed a flower-stability ratio of 72% on the second day, while the flower-stability ratio was 94% in the wet season. Pollinated (senescent) flowers had a stability ratio of 95% after 5 days during the wet season, but all pollinated flowers dropped after 5 days in the dry season, indicating that seasonal factors, such as water stress, can have dramatic effects on cocoa yields.

Degree of domestication influences susceptibility of Theobroma cacao to frosty pod rot: a severe disease devastating Mexican cacao

“…Here, we detected disease symptoms in the second week after fruit setting in the Criollo variety, and in the third week in the Trinitario and Forastero varieties (Figure 2). This pattern may be due to the arrival of conidia during floral anthesis, as previously reported by Omolaja et al (2009) and Frimpong-Anin et al (2014). Another possibility is that the strain of Moniliophthora roreri present in the area is very aggressive ).…”

Increased pollinator habitat enhances cacao fruit set and predator conservation

“…For the latter mechanism, increased water availability, from and retained by the decomposing cacao fruit husks, may have caused increased flower retention. Indeed, previous research documents higher levels of flower abscission (drop) and water stress during the drier seasons when rainfall and relative humidity are low (Adjaloo et al 2012, Frimpong-Anin et al 2014. Having more flowers during "wetter" conditions when midge populations are higher (Winder 1978) may enhance fruit production, due to better synchrony of flower production and pollinator density (van Schaik et al 1993).…”

A Crop Modelling Strategy to Improve Cacao Quality and Productivity

“…High winds can affect the availability of tiny flies pollinators from Diptera order and from the families of of the biting midges Ceratopogonidae, genus Forcipomyia [48][49][50] to reach the cacao flowers. However, the stability of cacao flowers is influenced by seasonal weather conditions (abiotic) and pollination (biotic) [51]. Therefore, pollinator population should be coincident with the phenology of the flowering cacao trees [52,53].…”