Abstract
In the previous paper, the influences of the mode of hill arrangement on the density effect for yield and various characters of rice plants was examined, in respect to the continuous changes from the square hill arrangement with a-plant-planting per hill to the square hill arrangement with four-plant-planting per hill, through the nest arrangement of hill. In this paper interrelationships between spacing density and the mode of hill arrangement in respect to the continuous changes from the square hill arrangement to the row arrangement pass through the rectangular hill arrangement is reported. The experiment was conducted at Kashimadai Farm, Institute for Agricultural Research, Tohoku University, in 1957. Fixing the distance between rows constant and increasing the density by reducing the hill spacing in the row, yield-density relationship coincided also with the low of C-D effect as was stated in the previous papers. In regard to the relative situations among square, rectangular and row arrangement of hill in the same density, the maximum grain yield per unit area obtained at the point which the retio of row distance to hill djstance in a row is 2 : 1 or 3 : 1.
