Abstract: The possibility of earlier sowing of maize before the optimal time has come (12-15 0C) relieves the manufacturers, which leads to more rational use of machineries, ensures early germination and fuller use of the moisture from the winter- spring period. This opportunity is achieved through a peculiar preserving of the seeds, considered as an additional part of their pre sowing preparation or complex preparation including the pesticides. Hydro phobia represents a construction of a protective water-impermeable layer of polymers with a different thickness and different time of degradation at definite conditions. The treatment of seeds with pesticides is done separately or in conjunction with the creating of the polymer covering. The exposure of the seeds in cold and moist soil to their germination is directly dependent on the thickness of the coating and the time for its breaking under the influence of the soil microbial activity. A correlation between the surface of corn from different fractions and their mass is established. A relationship between the thickness of the polymer coating and the period’s duration of its degradation is established. A function between the mass of grains, the thickness of the coating, the amount of polymer and the amount of the solvent is established. The period of stay of the seeds in the soil depends on the thickness of the coating and the time of sowing should end with the coming of minimum conditions (7-9 0C) for germination.

Key words: maize, hydro phobia, polymer, coating, terms of sowing.

Presentation: oral