Desimir Knezevic

Effect of nitrogen fertilization on winter wheat quality

A field experiment was conducted to investigate the effect of nitrogen fertilizer applications on some quality components of wheat. For winter wheat genotypes (Ana Morava, Vizija, L-3027 and Perla) were grown at Small Grains Research Centre Kragujevac in three years (2005–2007) at three levels of nitrogen fertilization (N 1 = 60 kg N ha −1 , N 2 = 90 kg N ha −1 and N 3 = 120 kg N ha −1 ). Zeleny sedimentation value and wet gluten content in divergent wheat genotypes were analyzed in depending on the nitrogen nutrition and years. Nitrogen fertilization significantly increased sedimentation value and wet gluten content. The highest increasing of both traits established in N 3 variant when applied 120 kg ha −1 of nitrogen. Genotypes reacted differently to N level increasing. Cultivar Perla had the highest value of sedimentation and wet gluten content and this cultivar the best reacted to increasing N levels. Statistically significant differences for sedimentation value and wet gluten content were found among...

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).

Influence of native root microflora on wheat growth

The influence of inoculation with native strains of root microflora (0.1 inoculum with dilution of 10-4) on plant dry matter weight, concentration and content of nitrogen was investigated in seven wheat cultivars (KG-56, Skopljanka, Partizanka, Sana, Srbijanka, Studenica and Tamis) by a scientific method “passage of diazotrophs”. The plants were grown through three successive experiments with diazotroph passage from in vivo conditions on the third generation of plants grown in in vitro conditions with the aim of adaptation and multiplication of diazotrophs in the rhizosphere of certain genotype. Through successive experiments a significant increase in dry matter weight, nitrogen concentration and content was achieved in most investigated genotypes. The most significant difference between inoculated and control plants in dry matter weight was found in cultivar Studenica in the third experiment (5.73 mg/plant), and the least significant in cultivar Tamis (0.43 mg/plant). The greatest difference in nitrogen concentration and content was found in cultivar Srbijanka, also in the third experiment (0.39%–0.21 mg/plant), and the smallest in cultivar Skopljanka (0.12%–0.07 mg/plant). The increase in dry matter weight, concentration and content of nitrogen in inoculated plants, especially the successive increase through the experiments is due to the activity of diazotrophes from the complex of soil microflora, and the ability of the genotypes of Triticum aestivum L. to perform a selection and multiplication of diazotrophs from its rhizosphere.