EVIDENCE AND SIGNIFICANCE OF SELF-POLLINATION OF AVOCADOS IN FLORIDA

Pollination was investigated in five avocado (Persea americana Mill.) cultivars during two seasons. In the first year,'Simmonds' and 'Hardee ') branches with inflorescences were covered with cheesecloth bags to prevent pollination by large flying insects during either or both the first (Stage I) and second (Stage II) floral openings. Adjacent, tagge d branches were left open as controls. The proportion of pollinated St age I flowers ranged from <1% in 'Simmonds' to 9% in 'Hardee.' Pollina tion rates in Stage II ranged from 15% in 'Simmonds' to nearly 69% in 'Hardee'. Pollination during Stage II was proportional to the number o f white stigmas available during that stage, Stage II pollination rate s for bagged flowers and open flowers were similar, even though large flying insects were barred from bagged flowers. In the second year, si milar experiments on cultivars Simmonds, Tonnage, Tower 2, and Choquet te provided results consistent with those obtained the previous year. Virtually no pollination occurred in bagged Stage I flowers in all cul tivars tested, and approximate to 1% of the open Stage I flowers were pollinated. Pollination of bagged and open Stage II flowers was genera lly the same within cultivars. The percent pollination of Stage II flo wers ranged from a mean of 4.3% to 35%, depending on cultivar. The res ults show that self-pollination during the Stage II floral opening is the primary means of pollination of commercial cultivars grown in Flor ida. Moreover, the presence of developing fruits on branches bagged du ring the flowering season demonstrated that fruit set can occur withou t pollination by large flying insects.