Reaktion verschiederer Mais‐Inzuchtlinien und ‐Hybriden auf steigendes Stickstoffangebot

Response of maize inbred lines and hybrids to increasing rates of nitrogen fertilizer The response of 8 flint and 8 dent inbred lines and 16 flint × dent single crosses to three rates of nitrogen fertilizer (80, 160, 240 kg/ha) were tested in the years 1983 and 1984 in field trials at one location. The material represents a broad range of maize genotypes not strongly selected for kernel yield. The mean kernel yield of all hybrids increased from the lowest to the medium N treatment by 7.6 % in 1983 and by 4.9 % in 1984. The highest fertilizer level resulted in an additional yield advantage in the two years of 6.1 % and 4.4 % respectively. An increased nitrogen rate had a positive effect on plant height, leaf area index, grains/cob, 1000 kernel weight, and protein content. Lodging resistance and dry matter content were not significantly influenced by N treatments. A significant interaction between genotype and N treatment was observed for leaf area index, 1000 kernel weight, and protein content, but not for kernel yield. The correlations of kernel yield with other traits investigated were not consistent over years and nitrogen treatments.