Verbesserung der Stickstoff(N)-Effizienz im Ökologischen Landbau - Bedeutung der N-Aufnahme- und N-Verwertungseffizienz bei Triticale, Weizen und Roggen

Summary

Organic farming systems are characterized by reduced nitrogen supply. Nitrogen (N) is one of the most important yield limiting factors and an essential component for proteins. For organic farming cereal varieties with high N use efficiency are required. The main components of N use efficiency are N uptake and N utilization efficiency. Triticale has shown to be very suitable for organic farming due to its tolerance to marginal conditions and high competition against weeds. Little is known about N use efficiency and its components in triticale. The aims of the study were to i) analyze the influence of N uptake and N utilization efficiency for improved N efficiency, ii) estimate quantitative genetic parameters for N uptake and N utilization efficiency, and iii) com-pare the findings for triticale with its parents wheat and rye. A total of 36 triticale, nine wheat and nine rye genotypes were tested in two locations with two N levels each, according to the rules for organic farming. The material was not pre-selected for N use efficiency. Significant genotypic variation was found for N use efficiency and its com-ponents N uptake and N utilization efficiency for triticale. So an important prerequisite for breeding for improved N use efficiency is met. The correlations between N use efficiency and its both components were high for all three cereals. N uptake and N utilization efficiency showed no significant association with each other. As a conse-quence these traits can be improved independently.