The results of studying resistance of mid-ripening spring wheat cultivars to root rot in the forest-steppe zone of Irkutsk region are presented. The study was conducted in a two-factor field experiment. Factor A – mid-ripening spring wheat cultivars: Tulunskaya 11 (control), Zoryana, Маrsianka, Stolypinka (new cultivars). Factor B – seeding dates: May 10, 20, 30, preceded by fallow. The experimental plot area was 70.0 m2. The experiment was repeated three times. Plot arrangement was randomized. Root rot prevalence was determined during the tillering phase of the crop. In 2018, the sowing dates did not affect the disease due to the long spring-summer drought (May-June) and a higher average daily temperature compared to long-term average values. In arid and cold conditions of May 2019, with the late sowing period (May 30), root rot prevalence was significantly lower than when sowing on May 10 and 20. In 2019, a higher level of the disease was registered than in 2018 by 14.3%. Significant differences in root rot prevalence in both years of research were noted between the control cultivar Tulunskaya 11 and the new cultivars of spring wheat Zoryana and Stolypinka. In the tillering phase of the latter two, disease indicators were lower by 5.6% and 10.5% in 2018, and by 8.8% and 7.9% in 2019, respectively. Маrsianka cultivar was at the control level for this indicator. The best cultivar under study was Stolypinka, which was not only less affected by root rot, but also gave a statistically significant yield increase of 0.16 t/ ha in 2018 and 0.22 t/ha in 2019.
Genotypic Variations in Growth Response and P-acquisition Efficiency by Spring Wheat Cultivars Exposed to Sparingly Soluble P-sources
