EFFECT OF AGROECOLOGICAL FACTORS ON VARIATIONS IN YIELD, PROTEIN AND OIL CONTENTS IN SOYBEAN GRAIN

This paper presents the grain yields and protein and oil contents of NS soybean cultivars of 0 maturity group grown for three successive years. The average yield for all cultivars was 3,335 kg ha(-1). The 2010 yields were significantly higher than the three-year average yield. The cultivar Becejka had a significantly higher grain yield per unit area (3,628 kg ha(-1)) and higher yields of proteins and oil (1,355 kg ha(-1) and 769.50 kg ha(-1), respectively) than the other cultivars. The highest protein content (40.56%) was recorded in 2008. The average protein content for all cultivars was 37.60%. The cultivar Proteinka had significantly higher three-year average protein content (38.21%) than the other cultivars, except Tara. The average oil content for all tested cultivars was 21.31%. The cultivar Afrodita had the highest average oil content 21.55%. Statistically significant differences were recorded in grain yield and protein and oil contents and yield, which were due to cultivar and test year. Soybean yield varied according to temperature and quantities and distribution of precipitation. Yield was positively highly significantly correlated with precipitation (r=0.94**), and negatively highly significantly correlated with temperature (r=-0.61**).