Evaluation of Different Procedures to Pollinate Self-Compatible 'Royal Red' Pitaya Under Protected Cultivation

The growing interest in pitaya has led to an increase in its cultivation worldwide. Unfortunately, the production of pitaya often depends on expensive hand-pollination. In this experiment, we compared the efficiency of different procedures in transferring pollen grains to flower stigmas and analyzed pollen-pistil interactions, fruit set, and quality in response in 'Royal Red', a self-compatible genotype of pitaya. The results show that pollen adhesion on the stigma achieved by transferring pollen with a paintbrush or with a duster was higher than pollen adhesion using blowers and much higher than the pollen load in the stigmas of open-pollinated or bagged flowers. However, good pollen germination and sufficient pollen tube growth in the flowers pollinated using blowers enabled high fruit and seed sets, leading to the production of fruits of commercial size in a less expensive manner. The results of free open pollinated and bagged flowers matched exactly, highlighting that the occasional insect visitors of the freely exposed flowers in the greenhouses of southeast Spain are not efficient pollinators. The high fruit set obtained in bagged flowers confirms the self-compatibility of this genotype, although the reduced pollen load and low pollen germination led to smaller fruit with fewer seeds.