THE INFLUENCE OF SEEDING RATE ON THE YIELD AND THE YIELD COMPONENTS OF WHEAT, OATS AND BARLEY

Abstract

The response of two wheat, three oat and three barley varieties to six seeding rates was measured at Beaverlodge, Fort Vermilion and McLennan for 3 years. Seeding rates of 1.5 bushels per acre for wheat and 2.5 bushels for oats give optimum yields at all locations. For barley, a rate of 2.0 bushels per acre is optimum at Beaverlodge and Fort Vermilion, but at McLennan, because of reduced emergence, a rate of 2.5 bushels is required. Variety and season do not alter appreciably the influence of seeding rate on yield.There are well defined locational and varietal differences in yield and in the four components of yield, namely (i) number of plants per acre, (ii) number of fertile heads per plant, (iii) number of kernels per head, and (iv) weight per 1000 kernels. These components explain certain locational and varietal yield responses but do not provide an absolute index of yielding ability.For all crops, the increase in seeding rate causes a linear increase in the number of plants per acre and a curvilinear decrease in the number of fertile heads per plant. There are also associated reductions in the number of kernels per head and the 1000-kernel weight, but the type of response varies with crop.Certain inadequacies are suggested in the present methods of selecting and testing varieties and hybrids of these crops for yield.