FLOWERING AND POLLINATION REQUIREMENTS IN CEREUS PERUVIANUS CULTIVATED IN ISRAEL

Abstract

The flowering and pollination requirements of Cereus peruvianus (L) Mill. (Cactaceae) were investigated in Beer Sheva, Israel, in a three-year-old plantation which had been established from seedlings, in order to domesticate this plant as a fruit crop. Plants flowered during the hot season (May-October), and flowers opened for one night only. Variations were observed in the flowers' opening time, with the early-opening plants beginning to open two hours before sunset, and the late-opening plants opening close to sunset. Flowers were visited only by day-active insects: the honey bee (Apis mellifera) and the carpenter bee (Xylocopa pubescens). The visitors' behavior indicated that they were involved in pollination. Early-opening flowers were visited both in the evening and in the morning, whereas late-openers were visited only in the morning. C. peruvianus was found to be self-incompatible, and fruit set did not occur when flowers were hand self-pollinated. Hand cross-pollination resulted in very high fruit set (92%) and heavy fruits with a high seed number. Fruit set, seed number, and fruit weight were lower in open-pollination than in hand cross-pollination. This indicates limited pollination or fertilization in open- pollination and might be related to the briefness of the bee visits, reduced pollen germinability, and stigma receptivity during part of the visit period.