【摘要】 对玉米小斑病的重要流行环节—孢子萌发侵入、病斑潜育显症扩展进行了定量研究。结果表明:叶面渗出物和花粉对孢子萌发及附着胞形成有明显的促进作用。叶面保湿时间(x)和附着胞形成率(y)的关系大体呈一“S”型曲线,两者关系可用回归方程y=exp〔-4.497exp(-0.098x)〕描述。温度(x)和附着胞形成率(y)的关系呈单峰曲线,两者关系可用回归方程y=sin(-3.371x+0.376x2-0.004x3)描述。随着生育期的推进玉米对小斑病侵染的抵抗力增强。增施磷、钾肥可降低小斑病的侵染率。小斑病在玉米上的潜育期为4~6 d,显症期约为7 d;病斑日龄(x)与病斑长度(y)的关系呈倒“J”型曲线,两者关系可用回归方程y=sin(42.645x-10.940x2+0.950x3)描述。更多还原

【Abstract】 Systemic quantitative studies on spore germination penetration and incubation symptomatic appearance of Bipolaris maydis were made.The results showed that substance in the leaf and pollen can accelerate the germination of spore and appressorium formation.The relation curve between wetness period(x) and rate of appressorium formation(y) is a "S" pattern,which can be described by regression equation y=exp(-4.497exp(-0.098x)).The relation between temperature(x) and rate of appressorium formation(y) is one summit curve,which can be described by regression equation y=sin(-3.371x+0.376x~2-0.004 x~3);Growth stage of corn has an effect on infection capacity of the disease.Rate of infection is high in prophase of corn,and is low in anaphase.P and K fertilizers can reduce infection rate of southern leaf blight of corn.Incubation period of the disease is about 4～6 days,appearance period is about 7 days;The relation between day-old of the lesion(x) and length(y) is an inverted "J" curve,which can be described by regression equation:y=sin(42.645x-10.940x~2+0.950x~3).更多还原