Application of mechanocomplexes of tebukonazole with vegetable organic polysaccharides for protection of spring wheat from leaf diseases

The possibilities of using the supramolecular complexes of tebuconazole with plant polysaccharides against diseases of spring wheat leaves were studied. The experiment (2018, 2019) was conducted in the crops of Novosibirskaya 31 and Obskaya 2 varieties in the forest-steppe zone of Western Siberia. The test results were compared with the ef  ciency of fungicide Folicur, EC (active ingredient tebuconazole, 250 g / l,   ow rate 1 l / ha). A single use of complexes of tebuconazole with licorice root extract (ratio 1 : 5) and arabinogalactan (ratio 1 : 10) with the consumption rate of 0.5 kg / ha at the beginning of wheat earing phase suppressed the development of Septoria, brown rust and powdery mildew within 30 days after treatment. The biological effectiveness of the studied complexes in the crops of cultivar Novosibirskaya 31 was high and accounted for 95.0% and 85%; 98.5% and 95.3%; 86.4% and 71.0%, respectively (the standard is 97.5%, 99.4% and 98.9%). The prevalence of Septoria in Obskaya 2 decreased by 92.3% and 94.0%, in the variant with Folicur – by 99.8%. Fungicidal complexes increased the assimilation surface of the   ag leaf of Novosibirskaya 31 by 34.8% and 35.8%, Obskaya 2 – by 32.4% and 22.9%, and in the variant with Foliсur – by 29.8% and 26.1%. There was also an increase in the number of grains in the ear in Novosibirskaya 31 by 26.7% and 23.3%, in Obskaya 2 – by 11.4% and 8.9%, with Folicur – by 27.6% and 7.1%. The mass of 1000 grains in Novosibrskaya 31 increased by 18.1% and 18.7%, in Obskaya 2 – by 13.7% and 14.1%, which is higher than in the variant with Folicur (9.1% and 6.2%). The grain weight in the main ear during treatment of Novosibirskaya 31 and Obskaya 2 wheat with the complex of tebuconazole with licorice root extract increased by 50.0% and 20.2%, with arabinogalactan – by 44.9% and 17.7%, which is higher than the standard (39.8% and 14.6%). The protection of crops by the studied complexes ensured an increase in the grain yield of spring common wheat Novosibirskaya 31 by 18.7% and 17.8%, Obskaya 2 – by 19.8% and 14.8%, (with Folicur – by 16.2% and 12.1%). The use of mechanocomplexes of tebuconazole with licorice root extract and arabinogalactan while reducing the consumption rates of the active ingredient by about 2.9 and 5.6 times ensures the ef  ciency which is not lower, but in some cases even higher than that of the commercial fungicide Folicur.