Dry matter and nitrogen accumulation and use in spring barley

During growth, kernel of cereals can be provided with carbohydrate and nitrogen (N) from the translocation of pre-anthesis accumulated reserves stored either in the vegetative plant parts or from current assimilation during kernel development. This study was conducted to assess the effects of nitrogen level and cultivars on dry matter and N accumulation and mobilization during pre-anthesis and post-anthesis. Twenty two-rowed spring barley (Hordeum vulgare L.) cultivars were grown on a non-calcareous chernozem soil in four growing seasons (1995-1998) at Novi Sad (45degrees20'N, 15degrees51'E, 86 in a.s.l.) at two nitrogen levels. Dry matter accumulation before anthesis ranged from less than 50% in unfavorable to 90% in favorable growing conditions. Dry matter translocation occurred in favorable growing conditions only. Pre-anthesis accumulated N represented 57-92% and 54-129% of total N at maturity at the low and high N levels, respectively. Translocated N represented 41-85% and 37-153% of grain N at the low and high N level, respectively. N losses occurred in favorable growing conditions when anthesis N exceeded 150 kg/ha. N accumulation during grain filling was in negative correlation with dry matter and N accumulation before anthesis. The N harvest index was 0.57-0.63 and 0.71-0.74 in unfavorable and favorable growing conditions, respectively. Selection of genotypes with a higher ability of pre-anthesis reserve utilization or genotypes with longer leaf area duration after anthesis may be two possible solutions in spring barley breeding for Mediterranean growing conditions.