Varietal Differences of the Rice Plant in Relation to the Resisting Capacity to Root-rot Disease, induced by Hydrogen Sulphide, and a Convenient Method to test Them

Conspicuous varietal differences were found with the rice plant grown on the soil of the paddy field where H2S is produced as regard to the degree of the root-rot caused by H2S. The varieties having high adaptability to "Akiochi" (fall-down) paddy field showed higher resisting capacity for the root-rot disease as compaired with those having low adaptability. The writer has devised a convenient method to test the varietal resisting capacity for root-rot disease. The method is as follows:- The plant is taken from the paddy field and its root is immersed in a diluted solution of H2S. After several days either the degree of blackening of the root due to FeS or the degree of root-rot is measured. The varieties resistant to root-rot have always lower degree of blackening and root-rot as compaired with non-resistant ones.