TERMS OF WINTER WHEAT TREATMENT BY FUNGICIDES TO CONTROL DEVELOPMENT OF BROWN RUST PATHOGEN

The terms of winter wheat treatment against brown rust pathogens (PucciniareconditeRob. exDesmf. sp. tritici) can greatly differ depending on climatic conditions and applied materials. The question is not studied enough for the Tambov region. In the production brown rust control fungicides are often used at the early periods of plant development (tillering, stem-extension stage). It makes the second treatment necessary as the preparation effect finishes at the maximum manifestation of disease (plant development phase-milky ripeness of kernels). In the Tambov region, the first pustules of brown rust appear on winter wheat plants in the beginning of the earing phase. This period occurs at the end of May/beginning of June. It is logical to assume that the maximum suppression of the disease on wheat will be achieved by spraying precisely at these times. To test this assumption, the field trials were conducted using the preparations ‘Reks duo’ and ‘Abakus’. They were used in the stem-extension stage and earing phase of winter wheat. Biological efficiency of fungicide spraying in earing phase of wheat was significantly larger (98.2–98.8%). Application of fungicides spraying in stem-extension stage was 85.6-86.5%. The amount of the saved yield was 0.60–0.81 t/ha (14.2–19.1%). Maximum values of winter wheat productivity (5.05 t/ha) was obtained when the preparation ‘Abakus’ was applied in earing phase. Wheat treatment by the preparations ‘Reks duo’ and ‘Abakus’ in earing phase was found more economically profitable, and the level of profitability was 130.9 and 55.0%, in stem-extension stage it was 109.2 and 35.4% respectively. The results of the trials showed that fungicides spraying in earing phase is the most optimal