Influence of technical and technological indicators on the harvest and post-harvest processing seeds of maize hybrids

The research result of technical and technological indicators, which largely characterize the seed condition and quality and allow to optimize the harvest and post-harvest processing of maize seeds, was pre-sented. The harvest and post-harvest processing of seeds are particularly affected by such indicators as: size, uniformity, level of damage, the content of self-hulled seeds in the total mass. In order to optimize the high-quality seed preparation, it is recommended to use for sowing the coarse seeds with a uniformity of more than 80 %. It was found that a uniformity of 80% or less causes the decrease of field seed germination (A) by 2–6 %, the extension of "sowing – full sprouts" period (B) by 6–8 days, and the decrease of index A/B by 32.1–41.0 %. Thus, the low seed uniformity has the negative effect. The indicator of uniformity is controlled by means the seed separation, and it must be at least 81 %. It is not allowed a presence of self-hulled seeds with embryo damage level more than 10 % in the seed material. With a higher content of self-hulled seeds in the total mass, laboratory germination decreases by 5–7 %, field germination – by 10–17 %, growth rate by number of sprouts – by 6–12 %, by sprout weight – by 8.0–11.6 %. To reliably predict the moisture loss rate of seeds at drying, it is proposed to determine the coefficient of the specific seed surface by a ratio of outer surface to volume. We established that an increase in the coefficient of specific surface area from 1.053 to 1.167 mm results to increase the moisture loss rate of seeds by 19.1%, and ears – by 30.9 %. The effectiveness for determination of the seed quality, in particular, its viability was confirmed by the cold test (germination at a temperature of 6–10 ºC). Key words: maize hybrids, technical and technological indicators, seed quality, harvest and post-harvest processing, fraction, cold tes