THE ROLE OF GROWTH REGULATORS IN THE FORMATION OF MAIZE GRAIN CROP YIELD

The article presents the results of studies on the effect of foliar treatment of plants with growth regulators on the formation of maize grain yield depending on the level of mineral nutrition. It was found that exogenous growth regulators had almost no effect on the number of ripened cobs on the plant, but stimulated the growth of the cob length: on an unfertilized agricultural background, the increase was 0.2-7.1 %, while when fertilizer was applied it was 2.4-6.1 %. With foliar treatment of the crops with Zircon and Plagron Vita Race on a natural agricultural background, the number of grains in the cob increased by 22-24 pcs (7.6-8.4%), and on a fertilized background the increase was 16-24 pcs (4.6-6.8%). The foliar treatment with phytoregulators on a natural agricultural background increased the grain yield per cob by 10.6 % and by 4.9 % on an improved mineral nutrition background. The higher grain yield per cob was obtained with Zircon and Plagron Vita Race treatment. In terms of grain yield at all levels of mineral nutrition, the most effective way was the use of the plant growth regulator Plagron Vita Race, which yielded an additional 10.1-13.5 % of production. In all years of research, exogenous phytoregulators showed better antistress properties in natural agricultural backgrounds