芋头腐烂病,又叫软腐病。除为害芋头外,还为害大白菜、马铃薯、番茄等多种蔬菜。在芋头产区均有发生。是芋头重要病害之一。一、发生规律。该病是由细菌引起的病害。病菌在土壤中病残体上越冬,也可在混有病株残体的肥料、垃圾中越冬,成为初侵染来源。通过昆虫、雨水及灌溉水进行传播。病菌多从植株的新鲜伤口侵入。高温多雨,湿度大时易流行,故在芋头生长过程中,尤其是生长的中、后期,雨水多,持续时间长;浇水过多,土壤湿度大易发病;地势低洼,易积水及连作田发病重。二、症状和诊断。初发病时,叶柄呈水渍状暗绿色,后由于养分和水分的输送受阻,叶片逐渐由绿变黄,并卷缩,最后干枯死亡。块茎多在收获前开始发病,块茎先从内部变软坏死,后整个块茎腐烂,并发出恶臭,但外表仍正常,最后由于茎内完全腐烂而形成空壳,重病株倒状枯 Taro rot disease, also known as soft rot. In addition to taro damage, but also against Chinese cabbage, potatoes, tomatoes and other vegetables. In the taro areas have occurred. It is one of the important diseases of taro. First, the law occurs. The disease is a disease caused by bacteria. Bacteria overwintering in the soil in the residual disease can also be mixed with the sick plant residues of fertilizer, garbage in the winter, a source of early infection. Spread through insects, rain and irrigation water. Pathogens invade fresh wounds from the plant. High temperature and rainy, easy to epidemic when humidity is high, so in taro growth process, especially in the growth of the late, more rain, long duration; excessive watering, soil moisture prone to disease; low lying, easy to water and even Field sick onset. Second, the symptoms and diagnosis. The first incidence, the petiole was water-like dark green, after the transport of nutrients and water blocked, the leaves gradually from green to yellow, and curling, and finally died of dryness. Tubers begin to morbid before harvest, the tubers become soft and necrotic from the inside, then the whole tubers decay and stench, but the appearance is still normal. Finally, the shell is formed due to complete decay in the stem,