Effect of Photosynthetically Active Radiation, Temperature, and Antitranspirants on Photosynthesis and Respiration of Leatherleaf Fern

Abstract

The influence of photosynthetically active radiation (PAR) and temperature on net photosynthesis and dark respiration was determined on leatherleaf fern [Rumohra adiantiformis (G. Forst) Ching] grown under 73% polypropylene shade. The maximum photosynthesis rate of 7.5 mg CO2 dm-2 hr-1 occurred at 500 μE m-2s-1 PAR. The light compensation point was 44 μE m-2s-1 PAR. A temperature of 20°C and 1000 μE m-2s-1 PAR was most favorable for net photosynthesis of leatherleaf fern. Use of the antitranspirant, a paraffin wax emulsion (Mobilcer A), at a 2% concentration reduced dark respiration by more than 50% and reduced net photosynthesis considerably compared to the control at 40°.