Seasonal Changes in Photosynthesis of Tea (Camellia sinensis L.)

Abstract

Seasonal changes in the photosynthesis of tea were measured with a 14C technique during 2 yr in Malawi. Photosynthesis did not decrease at the beginning of the cool season (May-Aug.), when the yield of tea declined. The fall in shoot production must therefore be caused by the redirection of assimilate to other parts of the plant. Daily assimilation was reduced by 25% at the end of the cool season when radiation was at a minimum, and there was an anomalous mid-morning drop in photosynthesis. Irrigation during the dry season (Sept. to mid-Nov.) had little immediate effect on shoot growth, but increased photosynthesis and reduced leaf scorch and abscission. Several months after irrigation, shoot extension was increased and dormancy was reduced.