Effect of treatment of common spring wheat crops with supramolecular complexes of tebuconazole on seed quality

Abstract

The effect of treatment of crops with supramolecular complexes of tebuconazole with plant polysaccharides on the infection and germination of spring wheat grain of a new harvest was studied. The experiment (2018, 2019) was conducted on the crops of varieties Novosibirskaya 31 and Obskaya 2 in the forest-steppe zone of Western Siberia. Crops were treated in the earing phase with tebuconazole mechanocomplexes with licorice root extract (ratio 1: 5, 1:10) and arabinogalactan (1:10) with a flow rate of 0.5 kg/ha. There was a decrease in the development of spike septoria in Novosibirskaya 31 by 97.6-98.5%, in Obskaya 2 by 78.6-98.9%. The biological effectiveness of the application of commercial fungicide Folicur, CE (active ingredient tebuconazole, 250 g/l, consumption rate 1 l/ha) was at a comparable level – 98.5 and 96.8-99.6%, respectively. Tebuconazole complexes with plant polysaccharides proved to be effective in inhibiting black point disease of wheat. Annually, the number of affected wheat caryopses was 1.54 and 1.50 times lower in Novosibirskaya 31 variety and 1.4-1.2 times lower in Obskaya 2 variety in the crops protected by tebuconazole with arabinogalactan compared to the treatment with Folicur, CE. Treatment with mechanocomplexes contributed to the reduction of seed contamination with phytopathogens. Complexes of tebuconazole with licorice root extract and arabinogalactan reduced the rate of infection with helminthosporiasis by 3.8 and 1.7 times (Folicur, CE – 5.5 times). Annually, seed contamination with Fusarium spp. was 8.3 and 3.7 times lower than in the control due to crop protection measures ensured by tebuconazole with arabinogalactan and licorice root extract. In the variants with the use of mechanocomplexes, seed infection with Penicillium spp. decreased. The biological effectiveness of tebuconazole with licorice root extract (1 : 5) was 69.9%, with arabinogalactan (1 : 10) – 58.1%, Folicur, CE – 67.7%. The best germination rate (95.0 and 89%), exceeding that of the standard, was obtained when both wheat varieties were treated with a complex of tebuconazole with licorice root extract (1 : 5). The complexes of tebuconazole with licorice root extract and arabinogalactan created by the mechanochemical method aiming to protect wheat plants from leaf diseases can have a significant healing effect on the emerging grain, improving its sowing qualities