Abstract
We have carried out some experiments to make clear the effect of the early transplanting culture in ill-drained field on which Akagare disease habitually occurs. The results obtained are summarized as follows. 1) In the standard Culture plot symptoms of Akagare disease developed toward vigorous tillering stage, growth of plants was suspended for a time and there was the dual growth appearance after recuperation, while in the early transplanting culture plot, they grew normally as well as those in the neighbouring normal field except the chlorosis in the central part of leaf-blade and the yield was greater by 48% than that of the standard culture plot in Same bad field. 2) In the early transplanting Cultureplot, soluble-K/protein-N of rice plant was lower and total carbohydrate/Total-N was higher in comparison with the standard culture plot in each growth stage. 3) Amount of total carbohydrate of rice plant in the standard culture plot went on decreasing after transplanting, while in the early transplanting culture plot, it was accumulated for half a month and the transition of rise or fall of it in each stage was as similar as in the early transplanting cnlture plot which grew ill neighbouring normal paddy field. 4) From these examination concerning in nitrogen and carbohydrate metabolism during growth period and from our previous reports as to the cause of occurrence of akagare disease, why such a good result has been obtained by the early transplanting culture in ill-drained field will be considered that the gain of resistance for the root-rot disease caused by the accumulation of starch, sugar and total carbohydrate in the plant at tillering stage lightened the injury of ricc plant.
