The use of biological pesticides for protecting plants from various infectious diseases and controlling abiotic stresses is becoming increasingly widespread in various agricultural crops. However, the effectiveness of biological plant protection is strongly dependent on various factors, in particular on weather conditions. To increase the impact of the use of biological products in plant protection against diseases, it is necessary to search for new approaches. One of the ways to increase the return on the use of biological products is the use of special adaptogens that increase the resistance of biological agents of biopesticides to the negative influence of the external environment. The Kazan State Agrarian University developed an adaptogen for bioagents of biological products based on alcohol extracts of millet. In 2019, on spring barley, the use of their mixtures with an adaptogen when spraying with biological products made it possible to increase the yield per 1,75 t / ha in comparison with the control and per 0,36 t / ha when using only biological products. At the same time, the effectiveness of control of the main leaf mycoses increased. In 2020, studies were carried out to evaluate the effectiveness of the use of biological products with the addition of the silicon-containing mineral diatomite when spraying barley plants. It has been established that the use of such formulations makes it possible to increase the productivity of plants, enhance the effectiveness of pathogen control in comparison with a standard biofungicide

The article presents the results of studies on assessment the productivity and the plasticity of spring soft wheat varieties in the conditions of the Republic of Tatarstan. The groups of varieties, differing in yield and biometric indicators, were underlined. The high dependency of productivity of spring wheat varieties to plant height index at Tatarstan was shown.

The article presents the results of studies, evaluating the plasticity of spring barley varieties in the Republic of Tatarstan. The groups of varieties, differing in yield and resistance to stress, were distinguished. The features, that allow to predict the yield of spring barley, were highlighted in the paper.

The most economical and environmentally safe way to control the disease is to use resistant barley varieties of plants. The use of molecular markers, associated with disease resistance genes, predetermine great possibilities, being used as a tool for the selection of breeders. The study aim is to identify varietal specimen, carrying genes, which are encoding resistance to loose smut of barley. A method of DNA-genotyping by PCR markers was used in the study. During the process of the research 83 varietal specimen have been tested, which were selected in the nursery Tatar Research Institute of Agriculture. The following two SCAR-markers, resistant to loose smut: Un8-700R and Un8-700 were used to identify the U8 gene. The studies found, that 36.2% have the gene, encoding the susceptibility to loose smut, in the genome alleles. 5.3% of the total number of varietal specimen was characterized by the presence of the resistance gene Un8 in the genome allele. The other specimen was observed no resistance gene to loose smut. The comparison with accounting data of loose smut spread, provided by the Barley breeding Department, showed no infestation of barley lines with resistance gene of loose smut in natural infectious background. As a result of molecular and genetic evaluation, the five specimen of nursery of Tatar Research Institute of Agriculture were identified with resistance genes in the genome alleles, which had been recommended, as a valuable genotypes for selection according to the loose smut resistance of barley.