1985 Volume 54 Issue 3 Pages 315-322
Characteristics of photosynthesis and transpiration of a single leaf or seedlings of Citrus species were compared to clarify the responses to climatic conditions of Citrus species.
The light compensation point of a single leaf was 1.5 to 3.5klx, which was similar in all species tested. There were remarkable difference, on the other hand, in the light saturation point among the species tested. That is, it was 10 to 20klx in ‘Morita’ Navel orange, 30 to 40klx in other several species and seemed to be 50klx or more in ‘Iyo’.
The optimum temperature for photosynthesis of a single leaf was about 25°C, though there was little difference depending on temperature at 20 to 35°C, in Wase and Common Satsuma mandarin. It was, however, a little higher, i.e. about 30 °C, in ‘Ohta’ Ponkan and ‘Kawano’ Natsudaidai.
The photosynthetic characteristics of the seedlings were similar to those of a single leaf, except that the light compensation point was slightly lower and light saturation point was higher than those of a single leaf.
The transpiration rate increased as temperature rose up to 30°C, decreasing at 35°C to a certain extent depending on the species. The transpiration rate of a single leaf of ‘Morita’ Navel orange was hardly dependent on the temperature. It was suggested, therefore, ‘Morita’ Navel orange had a typical characteristic as to the temperature response of transpiration rate.