Studies on the Chlorophyll Content of Satsuma Orange Leaves

Abstract

There are few reports that leaf color is related to physiological conditions of Satsuma orange trees. The present paper deals with relationship between chlorophyll content and strains of Satsuma orange trees, seasonal change of its content, and effects of light intensity and nitrogen on its content.
The chlorophyll content of Usami was 15mg per g dried weight, this strain contained the highest of the strains in this experiment. Sugiyama, Hayashi, Silverhill, Ishikawa, Yakushizi, Aoshima, Katayama, Miyagawa-wase and Okitsu-wase were 7-9mg, these strains were moderate. The strains of Oiwa No.5 and Zyuman were 5mg, these strains contained the lowest of them.
Satsuma orange trees had less chlorophyll content in the early season (January to June) than the late season (July to December) in the leaves. The leaves, exposed to sunlight in all seasons, had less chlorophyll content than shaded leaves on the same tree.
The chlorophyll content in exposed leaves decreased in winter, but this phenomenon was obviously stopped by enveloping with straw-mats or cheese cloth on the tree.
The more amount of nitrogen was fertilized to trees, the more contents of nitrogen and chlorophyll were increased. And there was a high positive correlation (γ=+0.95) between total nitrogen and chlorophyll content in the leaves. But when the total nitrogen content exceeded 3.5 percent in the leaves, chlorophyll content did not increase.