Sowing date as a response to ecological conditions in maize seed production

The environment protection, energy, and resources preservation are especially pronounced under present climate changes. In agriculture, these changes are recognised as drought, high temperatures, occurrence of stormy winds and hail. The aim of this study was to determine variations in seed morphology that are a result of different sowing dates in relation with agro-ecological conditions of maize (Zea mays L.) cultivation. The material used for the study encompassed three inbred lines (G1, G2, G3) sown every 10 d on five sowing dates (T1, T2, T3, T4, T5) starting from 1 April to 10 May, during 2 yr (Y1: 2018, Y2: 2019). The following physical properties of seeds were estimated: width (W), length (L), thickness (Tk), ratio of small (SF) to large fraction (LF) and grain yield (GY). The width was the highest in all three inbreeds on T4 (1.00, 1.03, 0.99 cm, respectively); T5 was the least favourable date for L (1.09, 1.12, 1.09 cm, respectively) while Tk was the lowest in G1 (0.51 cm) and G2 (0.51 cm) sown on T1. The most significant differences in the formation of physical properties occurred in seeds sown on T5 (p <= 0.05). The highest differences were observed in width between T5-T4 (-0.223 cm), in length between T5-T2 (-0.309 cm) and in thickness between T5-T3 (-0.129 cm). Later sowing dates favoured LF (85.2%) in comparison to SF (14.7%). Seed size variability participated with 50% in yield formation (R-2 >= 0.5).