Peas аgrophytocenosis formation with different levels of chemization chemization in the southern forest-steppe of Western Sibiria

This article deals with data of field experiments on the ordinary shallow low-humic medium loam cher- nozem soil under the conditions of the southern forest-steppe of Western Siberia in 2013-2015. Seeds of semi- leaflets peas of the Yamal variety were used there. Before sowing the pea seeds were dressed with the Maxim fungicide (2.0 l/t). For seeding and introducing fertilizers drills SCP-2.1 were used. The crops were sprayed with Pivalt herbicide (0.7 l/ha in 3-6 pea leaves stage) if necessary, with Karate Zeon insecticide (0.1 l/ha) and with desiccant. The use of the Pivalt herbicide provided decrease in the amount of all weeds by 65.8 % or by 79 pcs/sq.m. Along with the complex protection of peas plants the suppression of weeds increased to 78.3 %. The indicators of decrease in number of weed plants from the herbicide for ammophos (MAP) introduction were close to the said ones. The mass of weeds on control allotments made 328 g/sq.m. The release of sowing from weeds due to herbicide promoted an increase in number of pea plants on average in three years by 24 pcs./sq.m. The results of the impact of application of chemization means affected the weight of pea plants more significant- ly: in the control variant the figure was 685 g/sq.m and at the use of complex of plants protection by 52.7 % more. The degree of clogging of the pea crops was from high to very high. The share of weeds in the agrophyto- cenosis averaged 33.9 % over three years. Reducing the impurity of pea sowing exceeded 80 % (86.7-87.9 %), that is considered to be high efficiency for herbicides.