Drying of forage grass seed harvested at different maturity and its utility value in autumn and spring sowing time

Abstract

Tall fescue (Festuca arundinacea Schreb.), red fescue (Festuca rubra L.) and cocksfoot (Dactylis glomerata L.) are important fodder grasses, but in seed production, they are prone to seed shedding and certain yield losses. In practice, seeds are usually harvested at approximately 20-35% moisture content and then are additionally dried to the moisture content of 12% or lower. However, to prevent shedding, seed was harvested at 45% moisture content. The effects of drying temperatures of 70, 60, 50, 40, 30 and 22 °C on germination and dormancy of tall fescue, red fescue, cocksfoot seeds, harvested at moisture contents of 45, 35 and 25 %, were observed in the present study. The analysis was done immediately upon seed drying, then three, eight and fourteen months later, which corresponds to the autumn and spring sowing time in the continental part of central and south-eastern Europe. In all the three species, drying temperature of 70°C, regardless of the moisture content, and 60°C in the combination with a seed moisture content of 45%, reduced germination. After three months, the highest germination was detected in tall fescue harvested at seed moisture of 25% and dried at 50°C. Furthermore, the greatest germination in red fescue and cocksfoot was determined in seeds harvested with the moisture content of 35% and dried at 50°C. After eight months, the highest germination in tall and red fescue were determined in seeds harvested with the moisture content of 25% and dried at 40-50°C, while corresponding values in cocksfoot amounted to 25% and 22-30°C, respectively. A positive and significant correlation was established between seed germination and seedling vigour.