Comparison of light-intercepting characteristics between soybean (Glycine max) cultivar "Misato-zairai" and "Fukuyutaka"

Abstract

Light interception by leaves is crucial to crop production. In order to compare the light-intercepting characteristics of soybean 'Misato-zairai' (unstable yield) with those of 'Fukuyutaka' (stable yield), we cultivated these cultivars under the different soil water condition and measured the light extinction coefficient (K) with two different photometers. In 2010, 'Misato-zairai' had a higher proportion of upper-layer LAI and a significantly lower leaf inclination angle (closer to horizontal), but there was no difference in K between the cultivars. In 2011, irrigation increased LAI, but there was no difference in LAI between the cultivars. As before, 'Misato-zairai' had a significantly higher upper-layer LAI and a lower leaf inclination angle, but there was no difference in K. These suggested that unstable yield of 'Misato-zairai' should not be due to low light capture in spite of a higher proportion of upper-layer LAI and unerect leaflets.