The number of spring oat (Avena sativa L.) productive panicles in different environments

Although oat is a crop of humid regions, it is grown for livestock needs in the arid Balkan conditions too. For this reason, it is important to carry comparative trials on oats in different environmental conditions. The aims of this research were: to determine productive tillering and coefficient of productive tillering, components of phenotypic variance of productive tillering, parameters of stability and correlation with ecological parameters as well as agronomic and quality traits. The trial with seven oat varieties was carried out on three locations Banja Luka (BL), Novi Sad (NS) and Drinić (DN) during the 2003-2005 period. The trials in BL and NS were placed in lowland region while the trial in location DN was placed in the mountain region. On each location, the trial was sown in for replications and three planting times. The vegetation season in the 2003 was very dry with high temperatures, in the 2004 was an average and in the 2005 was humid with unequally distributed rainfall. There is no consistence with the number of productive panicles regarding the sowing time, year and location, in other words significant interaction appears. In the 2003, which was dry, the number of productive panicles was the smallest on the locations BL and NS (367/m2 and 332/m2, respectively) and the highest on location DN (435/m2). The highest number of panicles in the locations BL and NS was registered in 2004; 612/m2 and 455/m2, respectively. At the mountain location, the smallest number of productive panicles (401/m2) was determined in 2005, which was characterized with the sufficient of water. Higher number of productive panicles was determined in the earlier sowing times, especially on the locations BL and NS. The highest average number of productive panicles across years and sowing times on the location BL was registered with varieties Flemingsregent (535/m2) and Željka (516/m2), at the location NS with varieties Slavuj (447/m2), Flemingsregent (437/m2) and Željka (437/m2), and at the location DN with varieties Flemingsregent (399/m2) and Vesna (392/m2). The varieties Flemingsregent and Željka had the highest productive tillering in the favorable conditions and in the first sowing time. The lowest coefficient of tillering was determined in dry seasons and the highest in the humid ones. In the total variance, the highest proportion of variance originates from year and variety variability. After excluding the non-genetic proportion of the variance, the highest proportion of the variability belongs to variety (51,9%) and the interaction variety/year/location (20,2%), confirming the significant differences in the productive tillering among the varieties. Correlation between the number of productive panicles on the one side and the weather parameters and other agronomic traits on the other side depends on location. The concentration of the proteins and fat was in negative, and cellulose in positive correlation with the number of productive panicles. On the basis of the obtained results, one can select the most favorable variety for each location. It is necessary to carry out additional research regarding the tillering after using different sowing times in order to determine the optimal density for maximum yield. .