The data of three-year studies on determination of the optimal terms and rates for the herbicide Puma Plus use, EC on spring wheat crops are presented. The experiments were carried out on meadow-chernozem medium-low-humus medium-loamy soil in the southern forest-steppe of the Omsk region. In the variant without herbicide use, the proportion of weeds in the agrophytocenosis varied over the years from 12.9 to 19.0%, which corresponded to the average degree of infestation. Spraying of wheat crops began with the formation of 2-3 leaves in the culture and continued every 5 days. 20 days after the first period of herbicide application, 2-3 nodes were noted on wheat stalks (a variant with the last treatment period). Three herbicide rates were used – 1.3, 1.4 and 1.5 l/ha. At all treatment periods and herbicide rates, a weak level of contamination was achieved. The share of weeds was in the range of 0.1-5.8 %. Increases in the yield of wheat grain are significant for all terms and rates, which indicates the possibility of using the Puma Plus herbicide, EC from the formation of 2-3 leaves and up to the formation of 2-3 nodes on wheat stalks.

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The cultivation technology elements of hulless barley were studied at the experimental field of the Omsk State Agrarian University, including 3 chemicalization backgrounds: without chemicalization, with herbicides (Puma Super 7.5 + Sekator Turbo) and with herbicides + fertilizers (ammonium nitrate N60); 3 sowing dates: May 14th-18th, May 25th-28th, June 4th-6th; 3 seeding rates: 3.5, 4.5 and 5.5 million germinating grains per hectare. On backgrounds with no fertilizers, the field germination rate of the crop averaged 68.6% and 68.9%; it decreased to 68% at a fertilized background. Minimum germination rates were when sowing was on May 25th-28th; maximumwhen sowing was on June 4th-6th. When there is an increase in the seeding rate, the field germination decreases. The ratio of weeds in the control variants averaged 25.4%, herbicides reduced the weed ratio to 3.9 -8.2%; the effectiveness of herbicides at a fertilized background was lower. The weed ratio decreased from the early to later sowing dates and as the seeding rate increased. In plots without chemicalization, the weight of one weed plant was 1.80 g, in variants with herbicidal treatment -1.91-1.92 g. It reached its maximum value on crops that were sowed at the third decade of May. The weight of one cultivated plant at a background without chemicalization was 3.89 g, at a background with herbicides -4.44 g, at a background with fertilizers and herbicides -5.03 g; an increase in the seeding rate led to a decrease in the weight. In control variants, an average of 42.9% of barley plants survived; 51.0% -with the use of herbicides; 49.0% -with fertilizers and herbicides. As the seeding rate increased, the viability was reduced. Thus, the optimal conditions for the development of barley plants in agrophytocenosis were formed at the background of the use of nitrogen fertilizer (N60) and spraying of crops with a mixture of herbicides Puma Super 7.5, oil-water dispersion and Sekator Turbo, oil dispersion.

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