Abstract
Relation between phosphorus, nitrogen and potassium contents and the emergence rate of T1 (tiller in axils of the first leaf on main stem leaf) in wheat varieties having different adaptability to low available phosphoric-acid was examined in Andosol. Three varieties of wheat were cultivated in low available phosphoric acid field and improved field by the application of additional phosphoric-acid and stable manure. Phosphorus content of shoot and root of three varieties in low available phosphoric-acid field. In cv. Asakazekomugi and Norin 61 having low adaptability to low available phosphoric-acid soil, the emergence rates of T1 were decreased at shoot phosphorus content less than 0.5%. In cv. Norin 64 having high adaptability to low available phosphoric-acid soil, the emergence rate of T1 was sustained at 0.3% phosphorus content. The application of additional phosphoric-acid and stable manure increased not only phosphorus content, but also nitrogen and potassium contents of wheat plants. Partial correlation coefficient between phosphorus, nitrogen and potassium contents and the emergence rate of T1 indicated phosphorus content predominantly affected the emergence of T1. It is considered that the high emergence rate of T1 of Norin 64 in low available phosphoric-acid soil was due to high tillering ability to low phosphorus content in plants.
