Pollination and fruit set in two species of pumpkin in lowland Papua New Guinea.

Abstract

Two species of pumpkin were grown under lowland conditions in Papua New Guinea (PNG). These were Cucurbita moschata Duchesne, the most widely used species in lowland PNG and Cucurbita maxima Duchesne for which there is an unsatisfied market demand. The numbers of pollinators visiting open female flowers of C. moschata was significantly higher for flowers which developed into fruits. Although planted in adjacent plots and available to the same populations of pollinators, very few C. maxima flowers developed into fruits; female flower bud loss was the cause of low yields in this species. Hand pollination caused an apparent slight increase in yield for C. maxima. It was concluded that the failure of C. maxima to fruit satisfactorily in lowland PNG was due to physiological factors and not a lack of insect pollinators.