Formation of the productivity of winter wheat varieties with various degree of resistance under the influence of fungal diseases

Abstract

Purpose. To investigate the effect of fungal diseases on the productivity of winter wheat varieties of various resis­tance using artificial infection backgrounds. Methods. Field one – assessment of the resistance of variety samples to fungal diseases on infection backgrounds. Laboratory one – structural analysis of variety samples. Mathematical-statistical one – evaluation of investigation results and analysis of correlations between the obtained data. Results. Fungal diseases as the most widespread and harmful affect various organs of plants and cause poor harvest, deteriorate commercial and seed quality of grain. The results of field experiments in 2012–2017 on the effects of fungal diseases on the yields of winter wheat in the collection are given. It is defined that the infection of winter wheat with fungus ( Septoria tritici Rob.) and powdery mildew ( Erysiphe graminis DS. F. sp . tritici ) adversely affected the length of the ear, the number of grains in it, grain mass per ear and the thousand-kernel weight. However, productivity indices changed differently in investigated variety samples. The high-yielding wheat varieties ‘Sm u hlianka’ and ‘Novokyivska’ were the most tolerant to the fungal diseases. In the Septoria-resistant variety ‘Sm u hlianka’ at 75% of infestation the decrease in productivity was from 1,4 to 12,2%, whereas the in susceptible variety sample ‘UK 1731’ it was from 6,2 to 16,7%. A similar situation was observed in the variety ‘Novokyivska’ resistant to powdery mildew. Conclusions. Selected tolerant and highly productive varieties ‘Sm u hlianka’ and ‘Novo­kyivska’ (grade 7–6) can resist to Septoria disease and powdery mildew without productivity loss, they are considered as a promising source of resistance to these diseases and be of interest for further breeding in Ukraine.