The Effect of Cold Stress on Damping-Off of Soybean Caused by Pythium sylvaticum

Abstract

To improve our understanding of the timing of cold stress and its effect of P. sylvaticum was evaluated at 4, 10, and 18°C. The greatest seed on Pythium damping-off, we performed a factorial experiment with exudation was observed at 4°C. Low temperatures delayed mycelial two cold stress temperatures (4 and 10°C); exposure to 96 h of cold growth of P. sylvaticum, although the pathogen was still able to grow stress at 0, 1, 2, 4, 6, and 8 days after planting; and inoculation with at 4°C. Sporangia incubated for 3 h at 18°C in the presence of seed ex-Pythium sylvaticum-infested millet or control. Increased susceptibiludates had higher germination in comparison with sporangia incubated ity to damping-off resulting in reduced emergence was found in inocat 10 or 4°C. Moreover, more sporangia germinated in response to seed ulated plants when the cold stress period began 2 or 4 days after exudates that were previously collected from seed imbibed for 24 h at planting. In the noninoculated controls, no effect of cold stress on low temperatures (4°C). These results suggest that cold stress 2 to emergence was observed. Slower seedling growth was observed during 4 days after planting increases soybean susceptibility to damping-off, the cold stress period and in inoculated plants after exposure to cold presumably because of increased seed exudation and delayed seedling stress. Seed exudation, mycelial growth, and sporangia germination growth.