The aim of our study was to determine the effect of N top dressing on the yield components of three wheat varieties. Our experiments were carried out in Szeged – Öthalom on 10m2 experimental plots, three winter wheat varieties (GK Békés, GK Csillag, GK Petur), in two growing seasons (2010/2011, 2011/2012), 2 fertilizer treatment per growing season, with 3 repetitions, random block arrangement. The yield components were evaluated by kind of Sváb cumulative yield analysis (SVÁB 1961, 1962). The cumulative yield production analysis gives opportunity for graphic representation of plant development, where horizontal axle (x) represents yield components (end products of different development stages) per unit area in developmental order, and vertical axle (y) indicates the percent value of yield components referring to a basis for comparison. In the course of cumulative yield production analysis the followings are considered as yield components: A=number of seeds m-2, B=number of shoots m-2, C=number of ears m-2, D=number of spikelets m-2, E=number of grains m-2, F=grain weight m-2. The examined genotypes have a characteristic development line, the relative positioning of their yield components shows the characteristic features of the variety. GK Csillag is an extraordinarily tillering, number of shoot per unit area, number of ear, number of spikelet and number of grains are favorable. GK Békés and GK Petur are characterized by a larger thousand-seed weight. The plants which didn't get the early spring nitrogen dose, couldn't tiller as the ones received the N treatment in time. The April and May nitrogen surplus is beneficial for the ear number and grain number value of winter wheat. The delayed, higher doses of nitrogen fertilization cannot compensate the backlog of plants, so it is result poor yield. The continuous, issued in several installments N-dose is preferable for winter wheat, so it is result higher yield as a large amount of N applied to a few times.

winter wheat, nitrogen fertilization, N top dressing, yield component

field crops and pastures

Presentation: poster