A comparison of spring barley grown in England and in Scotland. 2. Yield and its components

Abstract
Yields of two spring barley varieties, Golden Promise and Maris Mink, were greater at the Scottish Plant Breeding Station (SPBS) than at the Plant Breeding Institute (PBI) in both 1976 and 1977. In both seasons more ears per plant were produced and the number of grains per ear was greater at the SPBS. Weight per grain was greater at the Scottish Plant Breeding Station in both 1976 and 1977, but the distribution of grain size along the ears differed between seasons. Grain at the tip of the ears of plants grown at SPBS in 1976 was lighter than the corresponding grain on the Cambridge-grown plants. In 1977 the SPBS-grown plants had heavier grains at all the main shoot spikelet positions. At the SPBS the relative difference between main shoot and tillers 1 and 2 was smaller than at the PBI.These results are taken to indicate that the combination of climatic factors in Scotland affects plant development in such a way that intraplant competition is reduced and more spikelet primordia survive to form grains and more tillers produce fertile ears.