EFFECT OF PARTIAL DEFOLIATION ON GROWTH AND PHOTOSYNTHETIC EFFICIENCY OF BEAN-LEAVES

Removal of leaves above the first trifoliolate leaf of bean plants (Phaseolus vulgaris L. ''Canadian Wonder'') induced more rapid leaf expansion, a larger final leaf area, higher dry weight, lower specific leaf area, and higher photosynthetic rates in the first trifoliolate leaf compared with undefoliated controls. Removal of the primary leaves just after they unfolded induced more rapid initial leaf expansion, smaller final leaf area, lower dry weight, higher specific leaf area, and initially higher but subsequently lower rates of photosynthesis in the first trifoliolate compared with undefoliated controls.