Goal. To study the effectiveness of the use of associative Azospirillum brasilense diazotrophs 10/1 to increase the yield and improve grain quality of spring triticale. Methods. Microbiology, gas chromatography, field experiment, and statistical. The objects of study-plants of spring triticale of varieties Oberig Kharkivskii, the strain of associative nitrogen-fixing bacteria Azospirillum brasilense 10/1. Field experiments were carried out in conditions of Ukrainian Polissia (Institute of Agricultural Microbiology and Agroindustrial Manufacture, NAAS, Chernihiv). The inoculation of seeds of triticale was carried out with 3-days culture of bacteria A. brasilense 10/1 for 2 h before seeding at the rate of 200-300 thousand bacterial cells per seed. Processing of experimental data was performed using the computer program Microsoft Office Excel. Results. It is established that the strain A. brasilense 10/1 positively influenced the growth and development of spring triticale due to improved nitrogen nutrition of plants and the ability to produce growth-stimulation substances. Use of the strain A. brasilense 10/1 for preplant bacterization of seeds triticale provided the increase in crop yield by 0.5 t/ha, or of 16.39% compared to control. Positive influence is revealed on a mass of grains in one ear and weight of 1000 grains. These indicators increased in the variant with inoculation on average on 16.8 and 11.9%, respectively. Also by inoculation of spring triticale with a promising strain of A. brasilense 10/1 the protein content in the grain increased to 14.06%, wet gluten-to the 35, 17, full-scale mass of grain increased by 7.3%. Conclusions. Taking into account the positive effect of associative nitrogen-fixing bacteria A. brasilense 10/1 on the growth and development of triticale plants, perspective variant is the creation of a biological product based on the strain for increasing the yield and improving the quality of the resulting products.

Potential activity of nitrogen fixation on washed roots of investigated varieties of spring triticale determined in field experiments has characterized by considerable fluctuations both during single phenophase in different years of research and throughout the vegetative period, that was caused by the influence of environment factors as well as by the existence of variability within the cultivar. The cultivar Oberig kharkovsky possesses the considerable polymorphism by the nitrogen fixation activity index in root zone of plants. Presowing inoculation of triticale seeds with active strain Azospirillum sp. 10 results in the increase of number of plants with higher nitrogen fixation activity on the washed roots.

Use of new strain of nitrogen fixing bacteria Azospirillum sp. 77 for inoculation of spring wheat and spring triticale permitted to form an effective associative system diasotroph - plant. The bacterization promoted the reliable increase of potential nitrogenase activity in root zone of plant by 38-220 %, activated the biosynthetic processes, in particular, glutamine synthetase activity increased by 57,0-71,9 %, content of protein in leaves - by 9,7-16,3 %, top of the plants - by 11,9- 18,9 %, weight of the roots - by 7,2-7,3 %.