TY JOUR TI ULTRASONIC WAVE PARAMETERS FOR PRE-SOWING TREATMENT OF GRAIN KW justification KW parameter KW ultrasound KW pre-sowing treatment KW Fresnel zone KW seeds KW water KW experiment JO Vestnik of Kazan State Agrarian University AU Volhonov, M.S. AU Mamaeva, I.A. AU Belyakov, M.M. PY 2025 IS 20 PB Kazan state agrarian University