Dates of sowing and the rate of nitrogen fertilization for spring wheat. I. The effects on grain yield
Pamietnik Puawski 75: 45-58
In field trials at the Osiny Experimental Station in Poland in 1976-8, spring wheat Alfa and Kolibri grown after cereals or root crops were sown as early as possible or 14-20 days later at 4.5 or 6.9 million seeds/ha, and given 0, 80, 120 or 160 kg N/ha. No interaction was found between date and rate of sowing and N fertilization rate. Late sowing reduced grain yields markedly in both cv., especially when it coincided with a late onset of spring, by reducing effective tillering and grain yield/plant and /ear. The opt. sowing rate was 4.5 million seeds/ha; the higher rate reduced productive tillering, grain yield/plant and grain yield/ear.