Growth and grain yield of wheat in relation to differences in soil groups. I. Growth and grain yield of wheat varieties under the same fertilizer conditions.

Abstract

The differences in growth and grain yield of seven wheat varieties cultivated in soils belonging to four different groups were examined under the same fertilizer conditions during two growing seasons, 1982-84. Plant growth was most vigorous in the Gray Lowland Soils (GLS). In the Red Soils (RS) tillering stopped and the leaf color became pale in late January. In the Thick High-humic Andosols (THA) and the Light-colored Andosols (LCA), tillering and leaf emergence rates were lower than in the other soils from the start of the tillering stage. The young spike and culm elongation occurred earlier in RS and later in THA and LCA. Grain yield was 649 g/m2 in GLS and 440-500 g/m2 in the other soils. Lower yield in RS was due to the decline in the spike number and grain weight per spike, whereas in THA and LCA it was due to the decrease in the spike number. These differences in the growth and grain yield of wheat in each soil were mainly associated with the soil fertility and soil temperature patterns. The varieties with the greatest yield was differed with each soil. In the most fertile soil, GLS, the yield of Asakazekomugi was the highest, because of the higher percentage of productive tillers (ca. 50%), large spike number, and less lodging which reduced the loss of grain weight per spike. In THA and LCA, the yield of Norin 64 was the highest, because of the vigorous tillering activity and the larger spike number. In RS the yield difference among varieties was not significant.