Studies in Natural Pollination of Cocoa in Ghana

Heterosis in Crosses of Theobroma cacao

“…In a less classical experiment, Glendinning (1964) demonstrated heterosis in early vegetative growth and precocity in hybrids obtained between Amelonado cacao from various sources and T6 imported from Brazil. In Ghana, Amponsah (1968) found heterotic pod production in Amelonado X Amazon and Local Trinitario X Amazon hybrids, observing also that early and sustained prolific yield of the hybrids was neither transitory nor had adverse effects in the general vigour of the plants.…”

Floral Nectaries and Trichomes in Relation to Pollination in Some Species of Theobroma and Herrania (Sterculiaceae)

“…With relatively few exceptions (Percival, 1965;Kevan and Baker, 1983), most of these dipteran-mediated pollination systems involve a generalist and casual associations offlies and flowers. Yet the study of cultivated Theobroma cacao L. (Sterculiaceae) in both the New and Old World tropics has revealed that 1) flowers possess an elaborate pollination mechanism judging from the arrangements of floral parts (see Cuatrecasas, 1964, andEntwistle, 1972 for reviews of this structure), and 2) the most commonly reported pollinators are dark-colored, smallbodied midges of the family Ceratopogonidae (Billes, 1941;Posnette, 1944Posnette, , 1950Soetardi, 1950;Saunders, 1959;Dessart, 1961;Glendinning, 1962;Fontanilla-Barroga, 1962;Hernandez, 1965;Soria, 1967;Kauffmann, 1975a, b;Entwistle, 1972;Soria and Wirth, 1974;Amponsah, 1975;Lucas, 1975;Soria, Wirth and Flores, 1976;Soria, Wirth andChapman, 1980, 1981;Winder, 1977Winder, , 1978Young, 1982Young, , 1983. But far fewer studies have dealt with a description of the specific features of T. cacao flowers that attract insect visitors and provide a nutritive reward during pollination.…”