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ARS Home » Southeast Area » Miami, Florida » Subtropical Horticulture Research » Research » Publications at this Location » Publication #234737
Title: Re-evaluation of honeybees and wind on pollination of avocado

Author
item YING, Z - TREC-IFAS,UF HMSTD FL
item DAVENPORT, T. - TREC-IFAS,UF HMSTD FL
item FABER, B. - COOP EXT,VENTURA CNTY, CA
item ZHANG, T. - TREC&UM MILLER SCH OF MED
item Schnell Ii, Raymond
item Tondo, Cecile

Submitted to: Journal of Horticultural Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/30/2008
Publication Date: 6/30/2009
Citation: Ying, Z., Davenport, T.L., Faber, B., Zhang, T., Schnell Ii, R.J., Tondo, C.L. 2009. Re-evaluation of honeybees and wind on pollination of avocado. Journal of Horticultural Science and Biotechnology. 84(3)255-260.

Interpretive Summary: Avocado (Persea americana Mill) flowers, with their synchronously dichogamous behaviour, are considered to be pollinated by honeybees, despite the lack of any direct evidence. Results in south Florida showed that avocado pollen was transferable by wind and dispersed over a brief period of time (15-60 min) each day. Ten ‘Hass’ avocado orchards in the Santa Clara River Valley, CA, USA, planted far from any known ‘Zutano’ polliniser trees, were selected to investigate the impact of honeybees on pollen transfer. ‘Zutano’ pollen (5 g per insert) was placed at the entry to beehives (approx. eight beehives per orchard) and refreshed four to five times during the flowering season. Successful pollinations were determined by parental analysis of harvested ‘Hass’ fruit from trees located at various distances from the beehives, and at three different stages of fruit development, using microsatellite DNA markers. The results showed no significant difference in the proportions of ‘Zutano’-pollinated fruit with respect to distance and/or development stage between orchards provided with beehives containing ‘Zutano’ pollen and those without supplemented pollen. This strongly suggests that honeybees are not the major pollinators of avocado, and that most avocado flowers are self-pollinated by wind.

Technical Abstract: Avocado (Persea americana Mill) flowers, with their synchronously dichogamous behavior, are considered to be pollinated by honeybees, despite the lack of any direct evidence. Results in south Florida showed that avocado pollen was transferable by wind and dispersed over a brief period of time (15-60 min) each day. Ten 'Hass' avocado orchards in the Santa Clara River Valley, CA, USA, planted far from any known 'Zutano' polliniser trees, were selected to investigate the impact of honeybees on pollen transfer. 'Zutano' pollen (5 g per insert) was placed at the entry to beehives (approx. eight beehives per orchard) and refreshed four to five times during the flowering season. Successful pollinations were determined by parental analysis of harvested 'Hass' fruit from trees located at various distances from the beehives, and at three different stages of fruit development, using microsatellite DNA markers. The results show no significant difference in the proportions of 'Zutano'-pollinated fruit with respect to distance and/or development stage between orchards provided with beehives containing 'Zutano' pollen and those without supplemented pollen. This strongly suggests that honeybees are not the major pollinator of avocado, and that most avocado flowers are self-pollinated by wind.