Biochemical factors associated with photosynthetic activity of cotton

Recent observations and measurements of whole leaf photosynthetic rates in cotton indicate that the productivity of leaves declines rather significantly prior to the completion of fruit development. These results, coupled with a loss of existing leaf area, indicate that yield potential is possibly not maximized due to inadequate organic material to completely fill the fruit. The photosynthetic rate decline is apparently related to source:sink ratios and possibly to the need for nitrogenous material by the fruit. The exact cause of the response is not known, although it is suspected that carboxylation enzyme activity is intimately involved.

The basic objective of this project was to develop an understanding of the causes of the photosynthetic rate decline in aging leaves of cotton.