INVESTIGATION OF SOWING DATE AND SEEDING RATE ON THE YIELD OF WINTER WHEAT

The winter wheat is one of the most important field plants in Hungary. The late years’ economical, climate and the cultivar changes gave new jobs to agrotechnique researches in Central Europe. Regarding the word of Agoston es Pepo (2005), agricultural and physiology speciality of the winter wheat cultivars have more important effect on grain yield as the pathology factors. Regarding the work of Ragasits (1998), at too close wheat population not only to increase of the fungous diseases, but the competition between plants through it induces selfregulation, which finally leads to the reduction of crops. On other hand Pekary (1971) got into the result that quantity increase of seeds did not influence the yield of winter wheat. Kuti es Szike (1985), Szalai (1985), Kristo et al. (2006) researches show that the breeds gave different crop yield sowing different seed quantity, however the growing season and the sowing date caused pregnant changes in the yield. Pan et al. (1994) establish that the seed increase in early and optimal sowing is unfavourable, but the negative effect of overdue sowing may compensate with increase of seed quantity. Anderson and Olsen (1992) experienced that the length of straw and percentage of lurch are increased, respectively the diseases and the frostbite prejudiced in the plants population, that Ragasits (1998) and Ogiuchi et al. (2004) confirmed as well. Pepo et al. (2006) emphasize particular function of breeds in the land. The author revealed that the facts of environment are determinative in the productivity and yield safety of winter wheat cultivars. Moreover Pepo (1995) and Baniuniene et al. (2005) reckon breed-growing season connection as very important fact. The object of our study is that we determine the effect of sowing date, seeding rate respectively growing season on the yield of winter wheat examined cultivars.