Photosynthetic and respiration rates of leaves damaged by rice leaf-folder Cnaphalocrocis medinalis Guenee

The rice leaf-Folder Cnaphalocrocis medinalis GUENEE is a serious pest in western Japan. We measured the net photosynthetic rate and dark respiration rate of undamaged, folded and damaged leaves using a portable system. The undamaged leaf net photosynthetic rate was 21.98 mu mol.m(-2).s(-1) at the leaf top and 21.81 mu mol.m(-2).s(-1) at the leaf base. The folded leaf net photosynthetic rate was 10.04-14.23 mu mol.m(-2).s(-1) or 42%-66% that of healthy leaves. The damaged leaf net photosynthetic rate of was -1.12 mu mol.m(-2).s(-1). The dark respiration rates of undamaged and damaged leaves were 0.45 mu mol.m(-2)s(-1) and 2.05 mu mol.m(-2)s(-1), respectively. The relationship between damaged leaf area (X) and net photosynthetic rate (Y), is Y=25.8-0.27 X (r(2)=0.97, p<0.01). The relationship between damaged leaf area (X) and dark respiration rate (Y) is Y=0.36+0.019 X (r(2)=0.68, p<0.01).