According to its chemical composition soya belongs to most valuable and rare plants in terms of a complex of its characteristic features. It uniquely combines the most important organic compounds – protein and fat (60% of seed mass) – the main components of its seeds, and 25% of carbohydrates, a complex of enzymes, vitamins and mineral substances. Therefore, soya protein and fat, their high content, good digestibility and availability for people contributed to rapid development of its world production and wide abundance in the southern part of Europe. The expansion of the area under soya is the way to increase soil fertility, replenish food resources and solve the protein problem in the world. Soya belongs to crops with low competitiveness with weeds. Thus, taking into account its high susceptibility to weed infestation, especially at the beginning of vegetation, and impossibility to protect the sown areas by means of only mechanical measures, chemical method remains an inseparable part of modern technologies of soya production.

Purpose and tasks. Wide abundance and harmful effect of weeds is one of the main reasons of poor yields of soya in all the areas of its cultivation. Extermination of weed components from areas under soya is the key prerequisite for increasing crop yields. This problem can be solved through the application of different weed control systems during tending of crops basing on agro-technical and chemical methods and their combined application. It is practically impossible to reach full weed extermination even applying highly effective weed control agents. Therefore, it is important to reduce the quantity of weeds to the level which is safe for the crop.

Research results. Soya yields are a complex index formed as a result of interaction of numerous environmental factors and biological properties of the variety itself. The efficiency of preparations used for treating soya crops to some extent defines the yields and quality of seeds.

The conducted research resulted in the establishment that the applied preparations influenced positively soya yields during all the years of the research. Together with this, simultaneous application of herbicides with Biolan facilitated the improvement of physical, chemical and structural indices of soya yields.

Thus, under the application of Gezagard 500 FW at the rate of 4,0 and 5,0 l/ha soya productivity increased by 5,6 and 5,8 cwt/ha respectively as compared to the control. At the same time under simultaneous application with Biolan the crop productivity increased by 7,7 and 7,8 cwt/ha as compared to the control. Similar results were also received after the application of Decilet applied at the rate of 0,6 and 0,8 l/ha. Here the crop productivity comprised 19,4 and 19,6cwt/ha which exceeded the control by 6,8 and 7,0 cwt/ha. Simultaneous application of Decilet with Biolan helped to increase the yield to 8,9 and 8,7cwt/ha which was the highest index of all the experiment variants.

Thus, under the application of Gezagard 500 FW at the rate of 4,0l/ha the quantity of beans was within 22,7 pieces and the quantity of seeds was 52,8. Simultaneous application of Gezagard 500 FW at the rate of 4,0l/ha and Biolan helped to increase the indices to 25,1beans with the quantity of 60,5 seeds. Under the application of Decilet at the rate of 0,6l/ha the quantity of beans was within 23,5 pieces with 62,0 seeds. Under simultaneous application of Dicelet at the rate of 0,6 l/ha with Biolan the quantity of beans and seeds increased to 27,2 and 64,6 respectively.

In the period of three years the weight of 1000 grains in the control variant was on the average of 136,4 g., at the same time in the variant with the application of herbicides it was within 145,0-148,0 gr. Under the application of herbicides with Biolan the indices increased to 151,3-153,0 gr. Grain unit was increasing depending on the rates of herbicides and their combination with Biolan. The highest grain unit was also observed in variants with simultaneous application of herbicides and Biolan.

The content of protein and fat in seeds is an important qualitative characteristic of crop productivity of leguminous plants including soya. Their content also determines the nutritive and feeding value of soya. The content of “raw” protein and fat depends mainly on the soya variety peculiarities, which explains the reason why content of the given indices does not differ greatly. At the same time “raw” protein and fat yield demonstrates more clearly the difference between variants which depended on the crop productivity. The application of the tested preparations facilitated the improvement of conditions of formation of the yield and therefore, the increase of “raw” protein yield as compared to the control.

The highest yield of “raw” protein among the variants, where Gezagard 500 FW was applied, was observed under simultaneous application with Biolan which was 7,23 and 7,12 cwt/ha according to the rates of application while in the control variant it was within 4,34 and 4,82 cwt/ha, and 4,82 cwt/ha in the variant with Biolan.

The highest yield of “raw” protein of all the variants was received due to the application of Decilet with Biolan which comprised 7,65 and 7,6 cwt/ha. At the same time the content of “raw” fat was also observed in bigger quantities which comprised 4,47 and 4,43 cwt/ha respectively. In the variant with the application of Biolan on its own, the yield of “raw” fat was 2,74 cwt/ha and 3,28 cwt/ha in the variant with hand weeding. In the variant with the application of Gezagard 500 FW, the content of “raw” fat depended on the rate of application and combination with Biolan. The highest indices were observed at the application rate of 4,0l/ha together with Biolan 20ml/ha which comprised 4,14 cwt/ha.

Conclusions:

1. Herbicides Gezagard 500 FW c.s. and Dicelit c.e. positively influence on the reduction of weed infestation on areas under soya which resulted in twice as big yields. In addition to this, structural, physical and chemical indices of seed quality improve.

2. Simultaneous application of herbicides with Biolan makes it possible to reduce the herbicides rates, pesticide stress of the environment and promotes biological technologies in soya production.

Key words: soya, herbicides, growth regulator, Gezagard 500FW, Dicelit, Biolan, structural data, mass of 1000 grains, nature of grain, “raw” protein, “raw” fat, efficiency, yield.