Suwan Tangmitcharoen, Wattanachai Tasen, John.N. Owens, and Jutitep Bhodthipuks

pp. 255 - 259

Abstract

Fruit set was determined at 2, 3 and 4 wks after pollination (WAP) in a teak seed orchard having 12x12 and 6x6 m spacings. Generally, the percentages of fruit set at 2 WAP were much higher than at 3 and 4 WAP. Repeated measures analysis indicated there was a significant difference in percent fruit set among different WAP for both spacings. Trigona collina
(stingless bee) commonly visited teak flowers, whereas Ceratina sp. (small carpenter bee) had fewer visits. At 4 WAP, the percentage of fruit set at both spacings for T. collina pollinated flowers was the highest, followed in decreasing order by open-pollinated, cross-pollinated, Ceratina-pollinated, and self-pollinated flowers. There was no significant difference in the
percent fruit set between the two spacings and among trees for all pollination treatments. A significant difference was detected
only for the percentge of fruit set among pollination treatments. Percent fruit set for self- and Ceratina sp. pollinations differed significantly from cross-, open-, and T. collina-pollinations. Only 3% of self-pollinated and 5% of Ceratina-pollinated flowers set fruit, whereas 9% of cross-pollinated flowers, 8% of open-pollinated flowers, and 13% of T. collina-pollinated
flowers set fruit. This result supports other studies that there is a relationship between size of pollinators and their behaviors. Our results suggested that T. collina, larger size, contribute to increased cross pollinations resulting in higher fruit set.