论文部分内容阅读
在荷花生长过程中,较为严重的病虫害主要有下列几种:一病害:1.黑斑病主要为害叶片。发病初期,叶上出现褪绿色的黄色病斑,后期呈圆形或不规则形,变褐色后并有轮纹,边缘有时有黄绿色晕圈,上生黑色霉层,直径5-15mm。严重时,病斑连片,除叶脉外,全叶枯黄。此病是一种真菌病害。在暴风雨多的时节发生严重,荷塘或盆栽连作,以及氮肥施得过多或在夏季水温过高等情况下,病害均很严重)防治方法:①加强栽培管理,及时清除病叶,发病较严重的盆株,需更换新土再行栽植,不偏施氮肥。②发病时,可喷施75%百菌清600-800倍液防治。2.褐斑病为害荷花叶片。在病叶上出现直径0.5-8mm大小的圆形斑点,呈淡褐色至黄褐色,边缘颜色较深。病害后期,病斑上生许多由真菌所引起的黑色小霉点。秋季多雨时发病较严重。病菌多在残体上越冬。防治方法:①清除病残叶,减少病菌来源;②严重者可喷施50%多菌灵500倍液或80%代森锌500-800倍液进行防治。3.腐烂病为害叶片、花梗和莲藕。为害叶片时,最初沿叶缘产生
In the process of lotus growth, the more serious pests and diseases are the following: A disease: 1. Black spot disease mainly leaves. Early onset, the leaves appear faded green yellow lesions, the latter was round or irregular shape, brown and have after the round pattern, the edge sometimes yellow-green halo, black mold students, diameter 5-15mm. Serious, lesion contiguous, in addition to leaf veins, the whole leaf brown. The disease is a fungal disease. In severe stormy season, lotus pond or pot plantation, as well as excessive nitrogen fertilizer or summer water temperature is too high, the disease is very serious) Prevention and treatment methods: ① strengthen the cultivation and management, timely removal of disease leaves, the incidence of more serious Potted plants, need to be replaced with new soil planted again, not partial nitrogen fertilizer. ② When the disease can be sprayed 75% chlorothalonil 600-800 times prevention and treatment. 2. Brown spot damage lotus leaf. Occurred in diseased leaves 0.5-8mm in diameter on the size of the round spots, pale brown to yellowish brown, darker edges. Late disease, disease spots many black mildew caused by the fungus point. Fall when the rainy season more serious. More bacteria in winter over the debris. Prevention and treatment methods: ① remove the diseased leaves to reduce the source of pathogens; ② severe cases can spray 50% carbendazim 500 times or 80% dexamethasone 500-800 times for prevention and treatment. 3 rot disease damage leaves, pedicel and lotus root. Damage to leaves, initially along the edge of the leaves