Aleksandar Paunovic

Sowing density and nitrogen fertilization influences on yield components of barley

Introduction The yield and quality of spring malting barley have a high degree of variability depending on both weather and soil conditions and applied soil and crop management. Adequate sowing density and nitrogen (N) applications by top dressing are important factors of barley growing and their optimal values are mainly associated with hereditary and environmental factors (Maksimovic et al., 1996; Paunovic, 2001; Lalic et al., 2006; Kovacevic et al., 2006). The ear number is the most important yield component of small grains. The tendency of barley to stalk lodging is an additional problem of N application by top-dressing. The aim of this study was to test the effects of sowing densities and N fertilization on yield components of five commercial spring malting barley cultivars under environmental conditions of central Serbia (Sumadija region).

Combining abilities for spike traits in a diallel cross of barley.

Five two-row winter barley (Hordeum vulgare L.) cultivars divergent in spike traits were crossed in all possible combinations excluding reciprocals to produce 10 F1 and F2 hybrids for analysis of combining abilities. The analysis of variance of combining abilities showed significant differences for GCA and SCA in F1 hybrids and F2 generation, suggesting additive and non-additive gene action. The GCA/SCA ratio in F1 and F2 indicated the prevalence of the additive component of genetic variance for spike length, grain weight per spike and spike harvest index. By contrast, the SCA variance for grain weight per spike was higher than the GCA variance, indicating the dominance of non-additive gene action. Good GCAs were found in parents having high values for spike length (Djerdap, NS-293), grain number per spike (Vada, Jagodinac), grain weight per spike (Vada, NS-293) and spike harvest index (Djerdap, Jagodinac). None of the parents had good GCA for all traits, suggesting a potential increase in combining abilities for spike traits. The best SCA were obtained mostly from crosses between parents having high x low, high x high or average x low GCA values. Parents having high GCA values may be used to produce improved lines in hybridisation programmes. Combinations with high SCA values may yield good segregating lines in further selection programmes.

The influence of nitrogen fertilization on protein yield and nutrient uptake in different triticale genotypes

Triticale is a first man made crop was designed in order to obtain a cereal, which combines good quality grain yield from wheat parent with tolerance to abiotic and biotic stresses (Giunta et al., 1999; Milovanovic et al., 2001; Ortiz–Monasterio et al., 2002). Triticale has potential of both parental species, strains and cultivars were found tolerant to drought (Jessop, 1996), soil acidity and aluminium toxicity. (Aniol, 2002; Baier et al., 1998; Milovanovic et al., 2001). In Serbia triticale covers about 35000 ha year for the period 2000–2004 (Statistical Year Book). Milovanovic et al. (1994) found that grain yield and certain quality parameters in winter hexaploid triticale were more dependent on season conditions in comparasion with wheat. High protein contents are characteristics for triticale. (Koc and Szymczyk, 1997; Milovanovic et al., 2001; Gastal and Lemaire, 2002; Gulmezoglu et al., 2006). Lorenz (1974) and Giza (1991) cited that triticale grains contained higher amount of P, Mg, Mn, Fe and Cu that wheat. The objective of this study was to find out the effects of different nitrogen rates to the protein yield of different triticale genotypes and the contents and uptakes of N, P, K and Ca.