Studies on the Growth and Yields of Winter Wheat in Highlands : I. Yield analysis of winter wheat in highlands from the view point of yield-constitutional factors. : II. Relation between weather factors and yield of wheat crop and its constituting factors.

Abstract

1. Low-yields of winter wheat in highlands depend on small numbers of ripened grdins per ear and also ripened grains per unit area. (Table 1) 2. It was found that yield and number of ears per unit area showed large variation, and the number of ripened grains per ear and weight of 1, 000 grains showed small variation. 3. Yields significantly correlated with weght of 1, 000 grains and also with number of ripened grains per unit area, but the number of ripened grains per ear correlated inversely with the number of ears per unit area (Table 2, Table 3). 4. Growth of winter wheat in highlands is shown in Fig. 1. More sunshines and less rainfall in autumn tillering times and in the period from heading to harvesting time, and higher temperature in spring tillering periods give favorable effects on grain yields. Correlation coefficients between yield constitutional factors and weather factors in Mid-March to early April are high. (Table 4)