Termoresistant and germination of maize hybrids seed depending on the mode their drying

Abstract

Heat (thermal) drying of maize seed is the most important operation in the process of post-harvest working. Typical drying mode is set on the basis of model calculations, namely static and dynamic characteristics of the thermal stability of maize seed and condition constant parameters of the drying process and it does not reflect the practical parameters in chamber dryer corn. Purpose. Determine the thermal resistance of different maize hybrids; establish the effect of drying regimes on the germination of seed. Research methods. Earcorn harvested at a moisture content of grain 17,3–3,3 %, dryness, threshed and seed germination was determined standard and cold germination method and sowing in the field. Research results . Seed germination varied depending on the harvest moisture, drying temperature and thermal features of the hybrids corn. Germination also affects seed germination method. Thus, in the standard thinning germination of seeds collected at different humidity and dried at a temperature 30 о C, was 93–100 %. When the temperature rises to 40 о C germination decreased slightly in those seeds which had 41,9 % moisture and above. At a temperature 50 о C germination remained high enough only for moisture 17,3–21,2 %. In cold thinning germination dependence of their harvest moisture and drying mode was much stronger. So, with a moisture content of 32–40 % within the maximum allowable temperature of heating of seed is 30 о C, with humidity 22–32 %, respectively 40 о C, and low humidity – 50 о C depending on hybrids corn. Kremen 200SV is the least thermostable hybrid was whose germination strongly reduced due to heating, as in the standard and cold germination. Conclusions. Revealed that the thermal stability of maize seed is formed due to the action of the complex biotica-abioticlly factors: temperature and moisture content of grain; varietal characteristics of the genotype; years of cultivation, physiological and biochemical status of the seed; its rate of dehydration. Optimum temperature for drying seeds with a moisture content of 22–40 % is respectively 50–30 о C.