Effects of Leaf Movement on Dry Matter Production and Photoinhibition
in Field Grown Soybean
Akihiro Isoda and Takashi Tomagae
Effects of leaf movement on dry matter production, yield and photosystem
II (PSII) in soybean were examined. The leaves of the upper layers
of the canopy were restrained by a net during the period from
the flowering stage to the harvesting sage, as compared with non-restraining
treatment of leaves. There was no significant difference in the
growth parameters (crop growth rates, leaf area index and net
assimilation rates) between the treatments during the treated
period. Differences in the seed yield and yield components were
not also found between the treatments. The leaf temperature in
the plot of the restraining leaves was higher than the non-restraining
treatment during daytime. Though the maximum difference was 5.5
ūC between the treatments on 16 Aug., the maximum leaf temperature
of the treated plot was lower than 40ūC. There were not found significant
differences between the treatments in quantum yield of photosystem
II (³PSII)and non-photochemical quenching (NPQ) except 16 Aug.,
which are concerning with the efficiency and photoinhibition in
PSII, respectively. A less gain in the leaf temperature by the
treatment in Aug. and enough available water in the field in Sept.
might not reduce the efficiency in PSII, consequently not decrease
dry matter production.