PRE-EMERGENCE HERBICIDE APPLICATION IN CORN CROP

Abstract

Presents the results of a study of the effectiveness of herbicides from different chemical classes for pre-emergence control of weeds in maize crops. Investigations were carried out in 2014–2016 in Cherek-Kolos LLC, Urvansky District, Kabardino-Balkaria Republic. The time of studies was distinguished by favourable moisture: the level of fallen September precipitation varied by year: in 2014 – 48 mm, 2015 – 24.3 mm, in 2016 – 51.4 mm and fairly warm weather. The conditions complied with the environmental requirements established for corn. According to the particle-size distribution, the soil of the pilot site is light clay over the whole profile with the content of “physical clay” 51.8 ... 58.9%. Among the fractions of particle-size distribution dominates large dust (30.4-35.8%) and silt (23.6-29.7%), whose portion in physical clay near 51%. The accumulation of the silt fraction (< 0.001 mm) is clearly traced in the upper horizons of the soil profile, that is, silting occurs in the upper horizon, which is determined by the indicator of removal – accumulation, the coefficient of which in the chernozem typical residual meadow is equal to 121.6. The clay fraction is an active part of the soil, it is a colloidal and precolloidal mass consisting of fine clay minerals, hydrophilic and capable of equivalent exchange reactions with the liquid phase. In pre-emergence control, the maximum suppression of perennial dicotyledonous weeds of 82.9-100% is achieved using the herbicides Anaconda, CE (1.6 l / ha) and Adengo, KS (0.5 l / ha). The effectiveness in suppressing perennial cereal weeds when using the herbicide Trophy 90, EC (2.5 l / ha) is 91.0%. Efficiency in the fight against gumaem with the use of the herbicide Lyumaks, SC (4.0 l / ha) is 83%. The grain yield of corn for pre-emergence use of the herbicides Anaconda, CE (1.6 l / ha), Trophy 90, CE (2.5 l / ha), Lyumaks, SC (4.0 l / ha) increases by 29-47% .