Effects of soil moisture up on the leaf quality of bright yellow tobacco

Abstract

l. Seedlings of bright yellow tobacco were. planted each, in a pot on 10th of May, 1951, and were divided into the following 3 experimental plots on the 1st of June : "damp" plot with moisture of 75-80% of the water capacity of the soil, "medium" plot with 45-55%, and "dry" plot with 30-40%. After about two months the plants were harvested and the structure of the leaf epiderm and the leaf qualities were examined. 2. The higher the moisture contents of soil, the higher was the plant height, the longer was the stem length and the larger was the leaf area. The number of internodes was not signicantly different between the damp and medium plots, but it was small in the dry plot. 3. In the dry plot, the numbef of epidermal cells per unit area increased. The thickness of the leaf blade showed no difference between the damp and medium plots, but in the dry plot it also decreased. No definite difference of the fresh or dry weight of unit area of the leaf was found among the plots, but the moisture contents of leaves were higher in the plots with higher moisture of soils. 4. As to the chemical composition, the nicotine content was higher in the drier soils, and the total nitrogen showed almost the same tendency. Soluble sugars were more abundant in the moister soils. Ash content was found definitely higher in the leaf of the dry plot Plant.