Effect of Irradiance on Chlorophyll Estimation with the Minolta SPAD-502 Leaf Chlorophyll Meter

Leaf chlorophyll content may be used as an indirect indicator of crop nitrogen status. Chlorophyll meter values (SPAD values) taken with the Minolta SPAD-502 chlorophyll meter in the shade plantOxalis acetosellaL. and in winter wheat (Triticum aestivumL.) varied by 15 and 8%, respectively, with variation in irradiance. The lowest SPAD-values were measured at high irradiance. During a natural night-day-night cycle SPAD values for winter wheat...