Yielding Ability of Erect-and Narrow-Leaved Rice Mutant in Heavy Manuring and Dense Planting Culture

Abstract

A dwarf rice mutant was induced through the chronic exposure of ⁶⁰Co gamma-rays. This mutant was crossed with a heavy-panicle type variety, and semi-dwarf plants permitting a more efficient distribution of light within the canopy were obtained. They along with current commercial varieties and the parent mutant were assessed for yield components, the yielding ability at three levels of nitrogen fertilizer by varying plant density and several other agronomic traits. The semidwarf rice possessed significantly higher rates of net photosynthetic CO₂ uptake compared with that of current commercial varieties, and it was improved in yield return by increasing nitrogen application. Manner of display of leaves could be manipulated by induced mutations.