The test weight of several winter wheat genotypes under various sowing dates and nitrogen fertilizer rates.

Four winter wheat varieties were studied at three sowing dates and five nitrogen fertilizer rates, under field conditions. On ave rage over all sowing dates and fertilizer rates was highest in the variety Evropa-90 (83.8 kg) and lawest in the variety PKB-Lepoklasa (82.0 kg). A test weight reduction was observed from the first to the third sowing date in all studied varieties, but mostly in the variety Pobeda. The highest test weight was observed at 60 and 90 kg N ha -1 while the increase of N rates over these values led to an insignificant decrease of test weight in all studied varieties.