Effects of Sowing Date on Pythium Root and Stalk Rot of Maize (Zea mays L.) in Kanto region

Abstract

In this study, the author aimed to determine the effects of sowing date on Pythium root and stalk rot (RSR), a disease that significantly hinders severely forage maize (Zea mays L.) production in Japan. Four F₁ forage maize varieties with different Pythium RSR resistant and mature characteristics were tested in Kanto region through sowing date-shifting experiments, sown from late April to late May. Experimental plots were used to assess the effects of the year, variety, and sowing date on Pythium RSR using non-parametric analysis of variance (ANOVA). All factors had significant effects (p < 0.001), and interactions between two or three factors were significant for all combinations (p < 0.05). Considering the ANOVA, simple interaction effect analyses, and meteorological conditions indicated that sowing in late April or late May could effectively reduce Pythium RSR frequency in susceptible varieties. The interpretation of these findings is complicated by the presence of interactions, highlighting the need for further data accumulation and research. Additional detailed analysis is also required once more relevant data is collected to clarify the impact of meteorological conditions on Pythium RSR frequency.