Evaluation of an Electronic Foliometer to Measure Leaf Area in Corn and Soybeans¹

Known areas were measured with an electronic foliometer to determine the errors involved with this instrument. Good agreement between measured and known areas was found and there was high accuracy and precision for both the conveyor belt and sheath method. Tests were made comparing the foliometer, a planimeter, and maximum length times maximum width (LW) for soybeans and comparing foliometer and LW for corn. There was close agreement between planimeter and foliometer measurements for soybeans (r = 0.99). The foliometer compared favorably with LW for corn (r = 0.96). Coefficients for converting LW measurements to leaf areas were determined for soybeans and three corn hybrids.