THE EFFECT OF VARIETIES, WAYS OF SEEDING AND YEAR ON WINTER-WHEAT YIELD FORMATION

Results of two-year trials (1991 to 1993) conducted with five winter wheat varieties in which we investigated the effect of different ways of seeding (muldboard, band and disc) and weather conditions of the year on formation and reduction of tillers and final grain yield showed statistically insignificant effect of ways of seeding and statistically highly significant effect of varieties and conditions of the year on maximum number of tillers, number of productive tillers and resulting grain yield. Most significant positive increase of maximum number of set up tillers on an average for the experimental period and variety was due to disc seeding in which increase amounted to 1.29 tillers per plant, i.e, increase of 25.9% compared with the lowest number of set up tillers - in muldboard seeding. Regarding productive tillering, the band seeding seemed to be an optimum way of seeding in which increment was 0.40 tillers per plant, i.e. 18.7% (in which limitation of reduction in the number of tillers by 7.1% was recorded) compared with the lowest number of productive tillers. Investigated varieties gave maximum grain yields in band seeding with average yield of 6.72 t.ha(-1), differences in grain yields between different ways of seeding were insignificant (statistically insignificant). Livia was the variety with highest intensity of tillering in trials conducted (6.28 tillers per plant) but at the same time it had highest reduction of number of tillers (68.19%), in which maximum grain yield of 7.00 t.ha(-1) was recorded, what is higher by 9.7% compared with minimum grain yield (6.38 t.ha(-1)).