Experimental evidence for stronger cacao yield limitation by pollination than by plant resources
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In: Perspectives in Plant Ecology, Evolution and Systematics, Vol. 12, No. 3, 08.2010, p. 183-191.
Research output: Journal contributions › Journal articles › Research › peer-review
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TY - JOUR
T1 - Experimental evidence for stronger cacao yield limitation by pollination than by plant resources
AU - Groeneveld, Janna Henrike
AU - Tscharntke, Teja
AU - Moser, Gerald
AU - Clough, Yann
PY - 2010/8
Y1 - 2010/8
N2 - Both pollination and resource limitation may cause low fruit:flower ratios in plants, but pollen and resource limitation have never been contrasted in commercially important crop species. Here we experimentally investigated the relative effect of pollen limitation and resource limitation in Theobroma cacao. In Central Sulawesi, Indonesia, we applied different relative levels of hand pollination (10%, 40%, 70% and 100% of available flowers up to 2. m height) to mature cacao trees in two separate experiments encompassing (1) different light (shade roofs) and nitrogen (fertilizer application) treatments, and (2) water availability (throughfall displacement) treatments. None of the resource availability treatments had a significant effect, while number of mature pods and yield increased non-linearly with pollination intensity up to 200% of current yield levels. The largest benefits were reached by increasing pollination from 10% to 40%, with non-significant increases beyond that level. Despite an increase of fruit abortion with pollination intensity, T. cacao yield is determined, at least on the short term, by the number of flowers pollinated. This suggests pollination deficit in crops can be very large and that a better knowledge of pollen and resource limitation to devise adequate pollinator management strategies may be critical for increasing production.
AB - Both pollination and resource limitation may cause low fruit:flower ratios in plants, but pollen and resource limitation have never been contrasted in commercially important crop species. Here we experimentally investigated the relative effect of pollen limitation and resource limitation in Theobroma cacao. In Central Sulawesi, Indonesia, we applied different relative levels of hand pollination (10%, 40%, 70% and 100% of available flowers up to 2. m height) to mature cacao trees in two separate experiments encompassing (1) different light (shade roofs) and nitrogen (fertilizer application) treatments, and (2) water availability (throughfall displacement) treatments. None of the resource availability treatments had a significant effect, while number of mature pods and yield increased non-linearly with pollination intensity up to 200% of current yield levels. The largest benefits were reached by increasing pollination from 10% to 40%, with non-significant increases beyond that level. Despite an increase of fruit abortion with pollination intensity, T. cacao yield is determined, at least on the short term, by the number of flowers pollinated. This suggests pollination deficit in crops can be very large and that a better knowledge of pollen and resource limitation to devise adequate pollinator management strategies may be critical for increasing production.
KW - Ecosystems Research
KW - Agroforestry
KW - Drought
KW - Fruit:flower ratio
KW - Nitrogen
KW - Theobroma cacao
KW - Water availability
UR - http://www.scopus.com/inward/record.url?scp=77955518046&partnerID=8YFLogxK
U2 - 10.1016/j.ppees.2010.02.005
DO - 10.1016/j.ppees.2010.02.005
M3 - Journal articles
VL - 12
SP - 183
EP - 191
JO - Perspectives in Plant Ecology, Evolution and Systematics
JF - Perspectives in Plant Ecology, Evolution and Systematics
SN - 1619-0437
IS - 3
ER -