【摘要】 芍药红斑病主要为害叶片和绿色茎。叶片受害后出现针头状的小点,最后扩展成不规则形大斑,正面为暗紫红色,背面为栗褐色;茎上为暗紫红色长圆形小斑。经鉴定病原为 Cladosporium Paeoniae Pass.。病菌生长和孢子萌发最适宜的温度为20—24℃。孢子在自来水和蒸馏水中萌发率为57.7％和43.0％,而在25—50％的芍药及牡丹煎汁中萌发率提高到90％左右。人工接种试验证明此菌可自伤口侵入,也可无伤侵入。在20—24℃条件下潜育期5—6天,8℃时潜育期延长到14天。叶片上病斑出现后扩展很慢,经2至2个半月才形成子实体。此病的初次侵染过程很长,并可能只有一次再次侵染。初侵染源是病株残茎和散落在地面上的病残茎及病果壳。病害的发生与侵染源的数量有密切关系。在不伤及芽的情况下将地上部分清除乾净,并移栽到无病地,或在冬季加垫厚度为15厘米左右的肥土;并于植株萌发初到开花前喷洒1000倍多菌灵3次,能有效地防治此病的发生。更多还原

【Abstract】 The Cladosporium red spot of peony appears mainly on the leaves and stems. Small, circular or oval discolored spots may appear on the ventral surface of the leaf and will finally extend to irregular large specks. Leaf spots show different colors on the two surfaces, which are dark purple above and dull chestnut below. On the stem there are small, dark purple elliptical lesions. The pathogen of the disease has been identified as Cladosporium paeoniae Pass. The optimum temperature for fungus growth and spore germination was found to be 20-24°C. The germination of spores in tap water and distilled water was relatively poor, the germination ratio being only 57.7% and 43.3% respectively. But in 25-50% peony and tree peony decoction, the germination ratio increased to 90% or so. In artificial inoculation the fungus could invade the host either through wounds or not.Results of a series of artificial inoculation experiments conclusively showed that the incubation periods varied with temperature, for instance, an incubation period of 14 days at 8°C reduced to 5-6 days at 24-25°C. Infection spots on leaves spreaded slowly and the fruiting body formed only after two to two and half months. The process of primary infection of this disease lasted rather long, and a secondary infection would be only once. The pathogen overwintered on the stems and fruitcoats of the diseased plant remained in the fields. The source of primary infection is of vital importance to the development of the disease. The disease can be effectively prevented by cutting off the stems above the ground as much as possible without injury to the bud, then transplanting the plant to the field where no disease existed or filling with fertile soil of about 15 cm thickness during winter. After that, spray with Bavistin, at a dilution of 1:1000. the first application being at the time when new shoots start to break through the ground, followed by a second and third before blooming.更多还原