Feijoa [Acca sellowiana (O. Berg) Burret] pollination: A review

Pollination is a key reproductive event conducive to fruit set in Feijoa (Acca seliowiana). Flowers are uniflorous, often forming clusters and hermaphrodite, bearing stamens and one elongated carpel. Stamens are numerous ranging from 60 to 120 per flower depending on cultivar. Flowers do not produce nectar. Pollen grains are small with average size of 10-28 mu m in diameter. Some cultivars bear barriers to self-fertilization e.g. self-incompatibility and dichogamy by protogyny. Feijoa can be self-pollinated and able to set fruit, or partially, self fertile. Wind is a possible pollination agent, but more research is required to confirm it as a vector. Cross-pollination occurs among different cultivars. Birds are also reported as important pollinators. Muscicapidae, Turdidae and Thraupidae bird families are important floral visitors. Birds feed on feijoa petals and transfer pollen grains from their body parts to stigma, promoting pollination. Insects, particularly bees are also reported to be pollinators. However, this again is controversial. The small body of bees is unable to establish contact with the stigmatic surface. Experimental pollen germination, viability and tube growth are dependent on cultivar and culture media conditions. Few studies have been conducted on pollen germination. This review seeks to expand the current information on feijoa pollination in tropical and subtropical environments. It is expected that this review will be useful to senior researchers, undergraduate students, growers and the general public.