Showing papers on "Plant physiology published in 1982"

The Effects of Acaricides on the Physiology, Growth, and Yield of Strawberries

Abstract: The influence of various acaricides on strawberry plant physiology, growth, and yield of the ‘Tufts’ variety strawberry was quantified. The mechanisms of pesticide-induced phytotoxicity were also investigated. Plants treated with propargite and fonnetanate hydrochloride generally had low numbers of leaves and reduced photosynthesis rates, and yielded the least fruit. Reductions in stomatal openings caused by phytotoxic acaricides were temporary. Long-tenn reductions in mesophyll conductance were apparent only in fonnetanate hydrochloride-treated plants. Cyhexatin-treated plants had high photosynthesis rates, but fruit yield was low compared with control-cyhexatin plants. Highest fruit yields were obtained from fenbutatin oxide-treated plants which exhibited high numbers of leaves, high photosynthesis rates, and no visible signs of phytotoxicity.

Photosynthetic characteristics of mesophyll eells isolated from sunflower (helianthus annuus L.) leaves.

Abstract: Mesophyll cells were isolated from sunflower leaves by an enzymic procedure. The cell suspensions possessed high photosynthesis rates. The products of cell photosynthesis were similar to the products of leaf disc photosynthesis. The relatively high radioactivity incorporated into malate after 14CO2 feeding suggests that PEP carboxylase might participate in CO2 fixation. Sunflower leaf extracts possessed a PEP carboxylase activity slightly higher than that of other C3 species. Inhibition of PEP carboxylase by maleate decreased cell photosynthesis by only 15% and the first products of cell photosynthesis were phosphorylated compounds. It is concluded that the high photosynthesis rates displayed by sunflower are not due to a parallel C4 pathway of photosynthesis but are rather dependent, at least in part, on the activity, or the amount, of RuBP carboxylase.