THE IMPACT OF THE CULTIVATED WHEAT VARIETIES ON FREQUENCY OF SEPTORIOSIS PATHOGEN OCCURRENCE

Abstract

One of the important tasks of agricultural production is an opportunity to predict changes in the pathogenic complex of grain crops. It is important not only to identify presence of certain pests, but also to estimate a degree of pathogen development, a role of the host varieties, their immunological potential. The species S. tritici occupies a leading position among the pathogenic complex of septorious spots. Most commonly the species S. tritici was identified on the winter varieties “Moskovskaya 39” and “Severodonetskaya Yubileynaya” with a frequency of occurrence of 90%. The same situation was identified among spring wheat varieties. The species S. nodorum occupies the second position in the distribution of septorious spots in the pathogenic complex. The species S. avenae was significantly inferior to the first two. For each variety being tested, the degree of damage made by a separate type of septoria was calculated according to the frequency of occurrence of each type of pathogen (a species composition) and the plant incidence of septoria. Among the spring soft wheat varieties, there can be identified “L 503”, “Favorit”, “Tulaykovskaya 10”. The septoria incidence degree of these varieties was 27.9%, 23.6%, and 29.3% respectively. Since the S. tritici occurrence in these varieties was more often compared to others (84%, 78%, and 83%, respectively), these varieties can be classified as poorly susceptible to the pathogen. The spring durum wheat varieties are more resistant to Septoriosis. The variety “Orenburgskaya 10” is found the best in this trait with only 17.1% incidence degree. The variety “Krasnokutka 10” showed the largest incidence degree (37.9%). Using the F-test (Fisher test) and the multiple comparisons (Bonferroni-Holm method), there has been shown a significant effect of the agroclimatic year conditions, a life form and the species on the formation of the species composition of Septoria spots. At the same time, the ratio of the species S. tritici, S. nodorum, S. avena throughout all years of study remains stable.