Effects of Leaf Movement on Radiation Interception in Field Grown Leguminous
Crops
IV. Relation to leaf temperature and transpiration among peanut cultivars*
Akihiro ISODA, ABOAGYE Lawrence Misa**, Hiroshi NOJIMA and Yasuo TAKASAKI
Abstract: Leaf movement and its relations to radiation interception,
transpiration and leaf temperature in peanut cultivars were examined. Five
cultivars (Chibahandachi, Tachimasari, Kanto 56, Valencia and Kintoki) were
grown under field conditions. At the pod filling period, leaf movement was
restrained by covering with a nylon net. The diurnal changes of leaf temperature,
the intercepted radiation of leaflets in the uppermost layer of the canopy,
and the infrared thermal images were compared with those of the control.
Transpiration rate and stomatal resistance were measured in the control
plants. The leaf temperature of the treated plants of Tachimasari, Valencia
and Kintoki were higher than those of the control. The control had a similar
leaf temperature to the air temperature. Chibahandachi and Kanto 56 had
higher leaf temperature in the control during the afternoon. The leaf temperature
of the treatment decreased in the afternoon. The control plants intercepted
greater radiation than the treatment in Kanto 56, Valencia and Kintoki on
cloudy days. On clear days, a greater amount of radiation was intercepted
in Tachimasari and Kanto 56. Chibahandachi had the greatest transpiration
rate, followed by Valencia, Kanto 56, and Tachimasari. The infrared thermal
images of Tachimasari and Kintoki were higher than those of Chibahandachi
and Kanto 56. It was therefore assumed that a cultivar with high transpiration
ability showed active diaheliotropism and a cultivar with low transpiration
ability exhibited active paraheliotropism.
Key words: Heliotropism, Infrared thermal image, Intercepted radiation,
Leaf temperature, Transpiration