Weed contamination of spring wheat crops with the application of resource-saving soil treatment technologies

The purpose of research is to study the influence of primary tillage systems on the weed infestation of spring wheat crops placed on green manure fallow in a five-field grain-fallow crop rotation. Objectives: to study the weed infestation of spring wheat crops; to establish the effectiveness of herbicide use; to determine the grain yield of spring wheat. The study was carried out in 2017–2022 in the conditions of the Krasnoyarsk forest-steppe on leached chernozem, which is characterized by an increased humus content (6.1–8.0 %) and a neutral reaction of the soil solution (pH – 6.1–7.0). The object of the study is spring wheat of the Novosibirskaya 15 variety. The research results showed that the bulk of weeds in the studied variants are represented by a group of young plants. Different tillage systems influenced the quantitative and species composition of weeds. When soil tillage is minimized, the number of weeds increases and their species composition changes. In spring wheat crops under the studied tillage options, the most numerous group of weeds were young ones. The most common species found in spring wheat crops were bedstraw (Galium aparine L.) and millet (Echinochloa crusgalli (L.). Their share in the total number of weeds in the variant with plowing was 71.4 %, without tillage – 81.4 %. There was a significant change in the share of biological groups of young and perennial weeds in the option without tillage during the study period. The share of young weeds in 2022 decreased compared to 2017 from 93.1 to 58.8 %, while the number of perennial weeds increased from 6.9 to 41.2 %.Over the years of the study (2017–2022), a change in the species composition of weeds was established. In the option without tillage, such species as yellow sow thistle, medicinal dandelion, hemlock, and small petal, which were absent in 2017, appear in spring wheat crops.