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100			_aSenevirathna A M W K
245		0	_aGrowth, photosynthetic performance and shade adaptation of rubber (Hevea brasiliensis) grown in natural shade
260			_bTree Physiology _c2003
300			_a705-712
520			_aWe compared growth, photosynthetic performance and shade adaptation of rubber (Hevea brasiliensis Muell. Arg) plants growing in natural shade (33, 55 and 77;reduction in incoming radiation) to control plants growing in full sunlight. Stem diameter and plant height, measured over a 15-month period, were greatest in plants grown in full sunlight, and both parameters decreased with increasing shade. At 7 and 14 months after planting (MAP), total plant dry mass was highest in control plants and lowest in plants in 77;shade. Expansion of the fourth leaf whorl, monitored at 5-6 MAP, was slowest in plants in 77;shade and fastest in unshaded plants, which had more leaves and higher leaf areas and inter-whorl shoot lengths. In response to increasing shade, specific leaf area increased, whereas leaf weight ratio and relative growth rate decreased. Chlorophyll a/b ratio decreased with increasing shade, indicating shade-induced pratitioning of chlorophyll into light-harvesting complexes. Compared to the response in unshaded plants, CO2 assimilation saturated at lower photosynthetic photon flux densities in plants in 77;shade, with a lower upper-asymptote to the light response curve. Chlorophyll fluorescence revealed no evidence of sustained photoinhibitory damage in unshaded plants. Dynamic photoinhibition decreased with increasing shade, with the greatest depression in the ratio of variable to maximal fluorescence around midday. We conclude that shade adaptation and shade-induced reductions in dynamic photoinhibition account for the enhanced early growth of rubber in light shade.
650			_aChlorophyll fluorescence
650			_aDynamic photoinhibition
650			_aLeaf area ratio
650			_aLeaf weight ratio
650			_aRelative growth rate
650			_aShade-plants
650			_aSpecific leaf area
650			_aSun-plants
700			_aRodrigo V H L
700			_aStirling C M
942			_cJS
999			_c60176 _d60176