Studies on Cool Injuries with Special Reference to Cultural Improvements in Rice Plants : III. The effect of compost application on cool temperature-induced sterility at the booting stage

摘要

The effect of compost application on cool temperature sterility at the booting stage was investigated in the field where water temperatures were precisely controlled (±0.5°C). Compost application showed a protective effect from yield loss caused by cooling treatment at the booting stage in the fields where the yield level at ordinary temperature was higher than 600kg/10a (Fig. 1). This protective effect from yield loss was primarily due to a decrease in sterility (Table 1). Sterility in the compost plots was lower than that in the control plots at the same level of leaf nitrogen content in the range above 3.0% of leaf nitrogen content (Fig. 2). Carbohydrate content of the mixture of leaf sheath and culm was higher in the compost plots than in the control plots, when they were compared on the basis of the same level of leaf nitrogen content (Fig. 3). The fresh weight of root was greater, and the activity of α-naphthylamine oxidation in root was higher in the compost plots than in the control plots (Figs. 4, 5).