The effect of genotype and agronomical practices on the structure of yieldfactors of buckwheat

Between 1995 and 1996 at two experiment sites we observed three varieties o f buckwheat (Fagopyrum vulgare L.): Pyra (Czech Republic), Lifestum (German y) and Hruszowska (Poland). The experiments were carried out in different a grotechnical conditions (the quantity of seeds sown 250 to 350 seeds per 1 m(2) and nitrogen dressing of 0, 30 and 60 kg N per 1 ha prior sowing). We observed the effect of genotype and the above mentioned environmental facto rs on the yield and yield characteristic (the number of plants per 1 m2, th e number of seeds per plant and thousand grains weight), as well as the pro cess of creation and reduction of flowers (the number of storeys, the numbe r of inflorescences, the number of flowers per plant) and formation of seed s. The seed yield was statistically affected by the choice of variety (the highest yield was found with the variety Hruszowska and the lowest with Lif estum), a site of growing and the nitrogen nutrition. Due to great differen ces in the weather between the experiment sites and during the experiment y ears the number of created storeys and flowers, and the number of ripe seed s as well as their mass differed significantly in all the genotypes. The po tential positive effect of more branches and of the greater number of creat ed flowers can be reached by both nitrogen dressing and lower plant density . The more branches the more asynchronic the ripening was and the greater w as the reduction of created flowers. The number of seeds per inflorescence and the number of seeds per plant was in a positive relation to the seed yi eld as opposed to thousand grain weight.