Determination of ecological plasticity and stability for female components of maize hybrids

Topicality. In Ukraine, a sharp manifestation of unfavorable climate elements for growing hybrid maize seeds, brought to the fore the tolerance of the female components of hybrids to environmental factors limiting the formation of potential yield. Therefore, the study and evaluation of the ecological plasticity and stability of female components are an urgent issue of the modern seed production of maize hybrids. Purpose. To determine the requirements of the female components of maize hybrids to environmental conditions. Materials and Methods. During the research, 20 female components of maize hybrids bred by the SE Institute of Grain Crops of NAAS were used. The female components were single cross sterile hybrids. The methodology of S. A. Eberhart, V. A. Russell, edited by A. Zykin and others, was used. The methodology is based on the calculation of two parameters: the linear regression coefficient bi (ecological plasticity) and the dispersion σd² (ecological stability). Results. The grain yield of the female components was determined in five years of the research. The influence of environmental conditions on the yield of female components of maize hybrids was determined. The female components were distributed according to the requirements for growing conditions. Conclusions. The most valuable, highly intensive female components include sister hybrids Kros253C, Kros256C, Kros247C and Kros238C with high environmental plasticity and stability. To realize the potential yield, they need a high agricultural background under favorable weather conditions. Female components Kros364M and Kros368M with high regression coefficient and root mean square deviation are less valuable because their high plasticity is combined with low yield stability. It is desirable to grow these female components only on a high agricultural background under favorable climatic conditions to get the maximum yield. Hybrids Kros254M, Kros255M, Kros266S, Kros277M, Kros301M, etc., have low environmental plasticity and high yield stability. These hybrids will give maximum returns for minimum costs in extensive cultivation. Keywords: female component, yield, hybrid, adaptation, regression coefficient, root mean square deviation, stability, plasticity