Factors Affecting Soybean Root Colonization by Calonectria ilicicola and Development of Red Crown Rot Following Delayed Planting.

摘要: Field studies were conducted in 1994, 1995, and 1996 to determine the effects of planting date, cultivar susceptibility, soil pathogen population on soybean root colonization by Calonectria ilicicola subsequent development red crown rot. Early season roots was important for rot symptom development. Symptom more susceptible cultivar, Sharkey, reduced following delayed remained low less Cajun, regardless date. Taproot positively correlated with inoculum density during all three growing seasons but strongest 1994. Also, lateral only year which foliar symptoms detected. A substantial decrease along colonization, attributed high temperatures probably rainfall recorded that summer. The effect plant age examined exposing plants at different ages. Soybean most C. first week after seedling emergence. By second week, susceptibility nearly half, it near level next several weeks.