This research presents the seed production evaluation of the 23/78В х 23/57В sister-line cross, maternal component of two modified late maize hybrids of the Maize Research Institute – Kn M611 and Kn M625.
The aim is to trace the influence of the year in which the maize is cultivated and the plant density relation to the biology of the florescence of the studied genotype, as well as the relation to the grain yield and the quality of its seeds. It is determined that under optimum weather condition, the pollen keeps its vitality for up to 40 hours after its removal from the panicle and the stigmas – to the 13th twenty-four-hour period. The optimal density for breeding of the sister-line cross under non-irrigation is 6 500 plant/da. The researched indexes are changed to a greater degree under the influence of the climatic conditions over the years of the research, rather than under the impact of the plant density.