水稲鉄コーティング湛水直播における<i>Pythium arrhenomanes</i>によるイネ苗腐病の発生に及ぼす水条件，発育段階および温度の影響

Abstract

Incidence or severity of seedling rot was examined for rice seedlings grown from iron-coated seeds under various conditions or stages in pots infested with Pythium arrhenomanes to determine the best management practices. Disease incidence was significantly higher in flooded conditions than in drained. Rice seedlings were susceptible from just after germination, i.e., pigeon-breasted stage to the first-leaf stage, and became resistant to infection after the second-leaf stage. Disease severity was similar at 10-25°C when soils were flooded at different temperatures during the susceptible early stage. These results suggest that keeping the water drained from soils from germination until the first-leaf stage will control the disease on rice germinated from iron-coated seeds directly sown into flooded paddy fields.