BIOLOGICAL AND ECONOMIC EFFICIENCY OF METHODS OF AGROTECHNICAL AND CHEMICAL PROTECTION OF CORN FROM WEEDS

Abstract

The article presents the biological effectivenes of the use of agrotechnical and chemical protection measures against weeds in maize crops on sod-podzolic sandy loam soil. Two-year studies have shown that the use of agrotechnical measures alone is not enough to combat weed-borne agro-phytocenesis in maize crops. Applying only two inter-row treatments increases the yield of green maize, relative to the control variant, by only 3.2 times. This is due to a more favourable diet caused by the loosening of row spacing and the active growth of weeds in the crop rows. Treatment of maize crops with herbicides leads to an increase in the yield of the green mass of the crop by 9.4-9.7 times, where the biological efficiency against one-year weeds was 95.9-97.7%. The highest yield of 436 cents per hectare of green mass was provided by the use of Fultime herbicide in a dosage of 1.25 l/ha. Slightly inferior to it were the options with the introduction of Sancor (423 c/ha) and Lumax (432 c/ha), respectively. The appropriateness of the use of herbicides shall be determined taking into account the species composition of the weed agro-phytocenoz. If there are many-year-old weeds in the crop, it is necessary to use preparations from the group of derivatives of sulfonylurea, the negative impact on the yield of corn which is not detected in comparison with the herbicide of soil action Lumax. This herbicide has the highest efficacy against one-year weeds (97.7%) and at the same time does not have a toxic effect on Agropyron repens, which leads to an increase in the number of stems (157.3 pcs / m2) of this weed after the use of pesticide.