Physical characteristics of maize seeds and their technological significance in processing and storage of sowing material

Topicality. The research on the preparation of high-quality seed of maize hybrids based on the consideration of their technical and technological properties at the stages of harvesting, processing and storage is relevant today. Purpose. To study and determine the essential physical parameters that characterise technical and technological characteristics and affect the seed quality of maize hybrids. Methods. The research includes theoretical and practical calculations with a review of literature sources, laboratory and model experiments and the laying out of field trials, mathematical and statistical evaluation of the data obtained. The experiments were carried out according to standardised methods of DSTU and agrotechnical recommendations, and the source material was hybrids bred by the State Enterprise Institute of Grain Crops of the National Academy of Agrarian Sciences of Ukraine. Results. The most significant physical characteristics of seeds are evaluated: shape, linear size, volume and geometric surface of seeds, their weight and specific weight, mechanical strength of maize hybrids and self-pollinated lines, and differences between them are determined. Experiments on seed separation, drying and storage were carried out, and certain physical characteristics were identified that have a special impact on the technology of these processes and form the seed quality. Conclusions. The dry seed quality during the separation process is most affected by the linear size of the seed, in particular, seed width, depending on which the fractions with the highest germination and yield are separated (tailing through round holes of 8 mm and more in diameter). Drying is influenced by the coefficient that characterises the ratio of the geometric area to the volume of the seed; at a coefficient of more than 1.0 (in experiments – 1.14–1.22), the intensity of moisture transfer and the drying rate increase by 8.3–15.7 % compared to a coefficient of 1.0. During storage, especially long-term storage, the quality and resistance of seeds is affected by the equilibrium moisture content, which should be at the level of 12 %, depending on the environmental conditions. Key words: maize seed, harvesting, drying, storage, physical characteristics, germination, yield