Kiwifruit pollination by honey bees 1. Tauranga observations, 1978–81

Abstract

Observations for 3 seasons during the blossom period of kiwifruit (Actinidia chinensis Planch.) cv.‘Hayward’ indicated that honey bees (Apis mellifera L.) were by far the most numerous of the insects visiting the flowers in orchards in which honey bees had been introduced. Hairy col-letid bees (Leioproctus spp.) were observed on the flowers of 4 of 7 orchards in 1978–79, 6 of 9 in 1979–80, but none of 9 in 1980–81. However, their numbers were generally so low that, except in 1 orchard in 1978–79, and 2 in 1979–80, their effect on pollination was probably insignificant. Bumble bees (Bombus spp.) and other insects were too few to be of importance in the sites observed. Honey bee visitation to kiwifruit flowers in 1978–79 was reduced by competition from other pollen sources, which might explain the poor fruit size that season. Competition was minimal, and there was good bee visitation in 1979–80 (when fruit size was generally good) and in 1980–81 (when it was unsatisfactory). In 1980–81 there were more flowers and consequently more fruit, in all orchards compared with the 1979–80 season, and this physiological load probably caused some of the reduction in weight. In 1980–81, 32.7% of fruit weighed less than 72 g, even though fruit less than 93 g contained significantly more seed than in the previous 2 seasons. This suggested that pollination was satisfactory, but that adverse weather conditions may have retarded fruit growth. Even in poor seasons some orchards achieve excellent results, and in good seasons some orchards have very poor results, which suggests that factors such as position of male vines relative to females, cultural methods, and orchard microclimates may be important.

Keywords:

• Apis mellifera
• honey bees
• Actinidia chinensis
• kiwifruit
• pollination
• pollen collection
• plant breeding
• reproduction