The Harmfulness of Common Root Rot in Winter Wheat Varieties in Kazakhstan

One of the main drawbacks of winter wheat varieties cultivated in Kazakhstan is their lack of resistance to common root rot. In 2020-2022, samples affected by root rot were taken in the earing phase in stationary experiments of the department of field crops and plant protection of the Kazakh research institute of agriculture and plant growing in the Almaty region. The research aimed to study the harmfulness of common root rot in commercial varieties of winter wheat. The weather did not significantly affect the harmfulness of common root rot. The harmfulness of the disease depended on the variety and degree of disease infestation. These indicators correlated with indicators of plant height, spike length, number of spikelets, and number and weight of grains (p<0.05). All varieties were affected by the disease to a low and moderate degree. In the varieties Almaly and Steklovidnaya 24, yield losses from the disease were 6.4-6.8%; in Farabi, Azharly, and Zhetysu 8.8-9.4%; and in Naz 13.0%. A total of 32-41% of plants were affected by the disease to a low degree and 10-21% to moderate and severe degrees. With a low degree of infestation, yield decreased by 2.4-7.1%, and with moderate and severe degrees by 4.5-12.1%. Factors of the degree of plant infestation and variety correlated (p<0.05) with dependent variables of productive business, stem length, spike length, number of spikelets, and weight of 1,000 grains. Using the method of linear regression, the authors concluded that the winter wheat spikelet number variable was significantly influenced by the variables of stem number (medium correlation) and spikelet length (strong correlation).