The dissertation presents result of studies characteristics of yield formation and grain quality corn hybrids of different morphotypes depending on plant density, fertilizer doses and development of adaptive technologies for growing hybrids in conditions of the Right Bank Forest-Steppe of Ukraine. The adaptive capacity of eight corn hybrids regarding to yield formation and grain quality at compaction of sowing and growing doses of mineral fertilizers was established, depending on characteristics of plants morphotype and root system formation. Hybrids differ in the intensity of the leaf surface area formation of an individual plant and a sowing, development of root system, depending on plants density and the dose of fertilizers. The longest total root system is forming in hybrids Sensor, Mosquitо with combination of all studied elements. In hybrids Garant, Kubus the longest root system is forming with applying N90P60K60 and N120P105K105. With 60 thousand plants/ha is forming a powerful root system in all hybrids with growing fertilizing rates. With fertilizing rate increasing till N150P135K135, the root system length decreases till the level N90P60K60. Sowing with a density 90 thousand plants/ha, the development of root system is more intensive compare to the density 60 thousand/ha only with application N60Р45K45. With increasing doses of fertilizers till N90P60K60, the length is decreases in comparing with N60P45K45 (with exception of hybrids Dniprovskyi 257 and Sigma – compare to 60 thousand plants/ha). With introduction N120P105K105 and N150P135K135, the length of root system in all hybrids is reducing – plants switch mainly to the use of easily accessible nutrition. The yield of corn hybrids is 5.08 to 13.4 t/ha. Adaptive technologies of growing increase stability of hybrids yields. Corn hybrids are well adapted to changing conditions of growing, forming a stable high yield. Stability of hybrids is a relative indicator, reversed to plasticity – some hybrids with lower yields show rather high stability: Mosquito with 90 thousand plants/ha forms a high stability – 0.16–0.30 with plasticity 1.0–1.23 depending on fertilizer doses. Hybrids, which respond positively to optimal conditions of growing by increasing the yield and plasticity coefficient with 90 thousand plants per hectare and N150P135K135 are: Sensor, Alekksandra, Garant, KVS 381 – 1.37–2.10. Hybrid Cubus has a high plasticity with lower fertilizer doses: 1.62–2.13, and with N150P135K135 has a plasticity coefficient 0.63, indicating a lower level of plants adaptability at high fertilizing rates. The coefficient of plasticity by yield with 60 thousand plants/ha for hybrids varies from 0.52 to 1.71, 90 thousand plants/ha – 0.69–2.13. Is established general tendency of higher plants plasticity for standing density – 90 thousand plants/ha. The number of grains in a cob of corn hybrids varies from 418 to 680 grains, with an average number of grains – 469–636 pieces; weight of 1000 grains – 167–244 grams, the weight of grain in cob is 91.4–148 grams. The yield index varies greatly with corn hybrids rowing with different densities, variable fertilizer rates and weather conditions – 0.36–0.52. Under favorable weather conditions, the yield index has a significant range of variation. The yield index for application of high fertilizer doses is lower for all years and for all hybrids. The share of factors, involved in corn hybrids yield formation, is: «Weather conditions» – 33 %; «Variety» – 11; «Plants density» – 28; «Fertilizer rate» – 15 %. The data on possibility of controlling the quality of corn hybrids grain at the expense of fertilizer doses, plant density and weather conditions are presented. Corn growing is economically and energy efficient. Total costs for technology of growing
corn hybrids are 22.2–40.4 thousand UAH/ha; cost of grain – 3148–4406 UAH/ton, profit – 23.9–52.5 thousand UAH/ha. The energy efficiency ratio is from 4.38 to 6.78.
