In recent years, the use of all types of fertilizers has sharply decreased, which negatively affected the state of the agroecosystem, its stability and constancy, therefore, it is extremely important to replenish nutrients, including microelements, to maintain the stability of yields. The increasing attention of scientists and industrialists deserves the question of the use of micronutrient fertilizers in the plant nutrition system, as an important element of the technology of growing crops. It is especially important to study the various forms, types and timing of their introduction. The article presents the research results for 2019-2021 according to the effect of microfertilizer Oracle multicomplex (1.5 l/ha) applied foliarly during the development phases of plants of the mid-early hybrid Orzhitsa 237 MB (VVSN 13-15, VVSN 16-18, VVSN 59) against the background of mineral nutrition – N150P90K90. It has been established that on gray forest surface-gley soils of the Western Forest-Steppe zone, a high grain yield of the mid-early corn hybrid (FAO 200-299) of the Orzhitsa 237 MV ripeness group was provided both by favorable weather conditions and by the influence of the Oracle multicomplex. Foliar application of the Oracle multicomplex microfertilizer in the phase BBCH 13-15 (3-5 leaves) increased the yield increase versus control (without micronutrient fertilization) by 0.82 t/ha, by meeting the needs of plants of this period in available forms of phosphorus, nitrogen, zinc, when panicle axes were laid on the tops of the shoots, and lateral apical meristems (future cobs) formed in the leaf axils. The highest yield by 1.19 t/ha was obtained with foliar application of micronutrient fertilizer in the phase of 6-8 leaves (VVSN 16-18). In this phase, panicle flowers, pollen grains in the stamens, the number of ears and grains in a row were laid, therefore, the content of S, Ca, Mg, Mn, Zn in the fertilizer positively influenced the formation of the reproductive organs of maize plants. Under the influence of micronutrient fertility introduced into the phase of full panic appearance (VVSN 59), blooming and pollution of maize effectively taken place, which ensured an increase in grain yield – 1.27 t/ha. The difference in this indicator between the VVSN 16-18 and VVSN 59 phases was unreliable (0.09 t/ha). Balanced nutrition of plants with macroelements (N150P90K90 with a gradual introduction of nitrogen) and micro – Mn, Cu, Zn, Fe, Co, S, Mo contributed to the formation of a 55-59 g higher weight of 1000 grains. The total yield of the coarse and medium grain fractions was 91.5-92.1%, the fine one decreased by 30.6%
