GrnenorN, P., ToLr-cNA,en, M. eNo MuloooN, J. F. 1985. Effect of temporary N starvation on leaf photosynthetic rate and chlorophyll content of maize. Can. J. Plant Sci. 65: 491-500.The photosynthetic rate (P) of maize (Zea may's L.) plants grown under growth room conditions was studied during and after a 1O-day period ofN starvation. The relationships between P and chlorophyll content, and P and nitrogen content were examined. Nitrogen deprivation, from the l8th to the 28th day, induced a decline of maximum photosynthetic rate, respiration and chlorophyll content; this effect was reversible. Recovery of photosynthetic capability occurred within 10 cm of water was placed between the lamp and the chamber to absorb most of the infrared radiation. Screens made of cheese cloth were used to reduce irradiance reaching the leaf. Photon flux density was measured to the top of the cuvette with a quantum photometer (Lambda Instrument Ltd., Lincoln, Nebr.) and corrected for absorbance and reflection by the cuvette. Maximum photosynthesis (PMAX) was measured by a photon flux density incident at the leaf surface of 2050 pEm-2'seg-t (400-700 nm). Photosynthetic rates were also measured at 700, 340, 66 and 0 pE'm 2'sec '. Room temperature was maintained at 25 -+ l'C. Fig. 2. Maximum photosynthetic rate of the 6th leaf of the control plants and of plants grown with N-free nutrient solution from the 18th to the 28th days (conditions: 26-+ l"C;