Influence of light quantum on seed biochemical composition under herbicide load

The results of research of photosystem II in the soybean leaves under the influence of herbicides used in crops for weed control are presented. The biochemical composition of the latter depends on the process of assimilation of light quanta, ensuring the formation of organic substances in the leaves and their outflow into the seeds. The results indicate the effect of herbicides on the protein content in the seeds. The highest protein content (40.8%) on average for 4 years of research, was obtained in the seeds of plants of the control variant, the lowest (37.5%) this indicator was, when using Frontier into the soil. However, Frontier did not impact on the quantum yield of photosynthesis in a negative way. A positive impact of Pivot, Fabian and Pulsar was noted a month after their application, in the bean formation phase, of plants of these experimental variants, on the quantum yield of photosynthesis, which reached the optimal parameters (0.700-0.800 units). The highest rate (0.841 units)of the quantum yield of photosynthesis was in the variant with the use of Pivot herbicide, which indicates its stimulating effect in residual quantities on the absorption ofquanta of light. At the same time, an increase in the quantum yield of photosynthesisraised the content of amino acids leucine, isoleucine, and arginine,in the seeds, compared with the control. A decreasing trend (by 0.01-0.06%) in the phosphorus content in all variants with the application of herbicides, in comparison with the control,was noted.The content of potassium under the influence of Frontier,grew on 0.12% relative to the control. Herbicides did not have a significant effect on other indicators of the biochemical composition of soybean seeds. There was no significant dependence of the biochemical composition of soybean seeds on the quantum yield of photosynthesis, with the exception of some individual indicators of amino acid content using Pivot, which stimulates the process of assimilation of solar energy.