Complementary bee pollination maximizes yield and fruit quality in two species of self-pollinating pitaya

Abstract

Large-scale commercial production of pitaya is recent and there is little information on pollination and fruiting
in this crop. Therefore, the objective of the present study was to investigate if the Africanized honeybee (Apis mellifera),
frequent visitor of pitaya flowers (Hylocereus undatus and H. polyrhizus), plays any relevant role in the pollination of these cacti
species, both in terms of fruit quantity and fruit quality. The study consisted of four treatments: natural pollination; restricted
pollination; nocturnal pollination and pollination by A. mellifera, and all fruits were harvested and analyzed at 30 days after
setting. Each treatment was evaluated in the number of fruits produced, total weight of the fruit; skin weight; pulp weight;
longitudinal and transverse size; number of seeds; pH; acidity; total soluble solids (TSS); and TSS/total acidity ratio. Results
showed that these pitaya species differ in their dependence on biotic pollination for the production, weight and quality of fruits.
H. undatus did not depend on bees to set fruits but needed the moth Agrius cingulata to improve yield quality with larger and
heavier fruits. On the other hand, H. polyrhizus depended on biotic pollination to maximize fruit production and Apis mellifera
specifically to increase size and weight of fruits. In addition, the tested types of pollination influenced little the physical-chemical characteristics of fruits, being only relevant in the reduction of the pH in flowers pollinated by A. mellifera.