Barley has a long and intensive tillering period with a far greater stem number produced than the final spike number per harvest. The formation of a higher number of stems and spikes (total and productive tillering, respectively) is a negative malting barley trait because it induces smaller and shrivelled grains which considerably reduce its value for malt production. The investigation of the effect of fertilisation and planting density on the total tillering of spring barley was conducted over a three-year period at the trial field of the Small Grains Research Centre in Kragujevac. Five two-rowed spring barley cultivars (the A factor) were investigated and they were: Kraguj, Dinarac, Dunavac, Jastrebac and Novosadski 294. The planting was carried out at optimal dates (February-March). Three planting densities (B) of 300, 400 and 500 germinating grains m -2 were used. N, P 2 O 5 and K 2 O were each incorporated at the rate of 52.5 kg ha -1 by basic fertilising and top-dressing was carried out in the tillering phase using 0, 30 and 60 kg ha -1 N (the C factor) during the month of April. The average total tillering for all investigated cultivars, planting densities and nitrogen rates in the three-year research period was 4.17. The highest average tillering for all planting densities and nitrogen rates was established in the Jastrebac cultivar (4.52), and the lowest one in the Kraguj cultivar (3.93). The planting density increase brought about a reduction in tillering. The difference in tillering between the planting densities applied, in all three research years, was highly significant. As opposed to this, increasing nitrogen rates used for top fertilisation induced a tillering increase. A highly significant tillering difference was recorded in all three years between the control variant N (0) and the rate of 60 kg ha -1 N. The differences between N (0) and N (30 kg ha -1 ) were statistically significant in the first two study years, and highly significant in the third year. The difference in tillering between nitrogen rates N (30 kg ha -1 ) and N (60 kg ha -1 ) was significant only in the first two research years. In the third research year, a statistically highly significant interaction between the cultivar and planting density (AxB) was registered, with the Jastrebac and Kraguj cultivars having expressed different tendencies compared to other cultivars.

tillering; planting density; nitrogen; spring barley

Presentation: oral