Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management†
1
Environmental Futures Research Institute, School of Environment and Science, Griffith University, Nathan, QLD 4111, Australia
2
Genecology Research Centre, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
3
Department of Animal Ecology, Evolution and Biodiversity, Ruhr-University Bochum, 44801 Bochum, Germany
*
Author to whom correspondence should be addressed.
†
Presented at the third International Tropical Agriculture Conference (TROPAG 2019), Brisbane, Australia, 11–13 November 2019.
Proceedings 2019, 36(1), 76; https://doi.org/10.3390/proceedings2019036076
Published: 21 January 2020
(This article belongs to the Proceedings of The Third International Tropical Agriculture Conference (TROPAG 2019))
Cross-pollination is essential for the reproduction of self-incompatible plants and it improves the yield and fruit quality of some self-compatible plants. Cross-pollination of clonal horticultural crops is achieved only when pollen from one cultivar reaches the stigma of another cultivar. We quantified self- and cross-fertilisation rates in macadamia nuts (Macadamia integrifolia, M. tetraphylla and hybrids) that were harvested at different distances from a cross-pollen source in two different plantation designs (mixed blocks of multiple cultivars vs. pure blocks of a single cultivar). We also estimated the distance of effective pollen movement, evaluated how different pollen parents affect nut quality, and assessed whether distance from a cross-pollen source affected the number of nuts harvested. We found that almost all nuts resulted from cross-pollination in both plantation designs, with almost all nuts being cross-pollinated even at 23 rows from another cultivar. However, most pollen did not travel far, and nearby cultivars were usually the pollen parent. Cross-pollination increased nut mass and changed the nutritional quality of the nut. The number of nuts harvested decreased with increasing distance from a cross-pollen source in large pure blocks, but not in mixed blocks. Dependence on cross-pollination coupled with low distances of pollen movement may cause suboptimal fruit set. Our results suggest that fruit set in macadamia plantations comprised of large single-cultivar blocks is limited and that plantations can benefit from closer interplanting of different cultivars
Keywords:
cross-pollination; nut quality; nutrients; fatty acid; pollen movement; macadamia
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MDPI and ACS Style
Kämper, W.; Wallace, H.M.; Ogbourne, S.M.; Trueman, S.J. Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management. Proceedings 2019, 36, 76. https://doi.org/10.3390/proceedings2019036076
AMA Style
Kämper W, Wallace HM, Ogbourne SM, Trueman SJ. Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management. Proceedings. 2019; 36(1):76. https://doi.org/10.3390/proceedings2019036076
Chicago/Turabian StyleKämper, Wiebke; Wallace, Helen M.; Ogbourne, Steven M.; Trueman, Stephen J. 2019. "Dependence on Cross-Pollination in Macadamia and Challenges for Orchard Management" Proceedings 36, no. 1: 76. https://doi.org/10.3390/proceedings2019036076
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