特性：屬真菌性病(bing)(bing)(bing)(bing)害(hai)(hai)，洋香瓜(gua)炭疽病(bing)(bing)(bing)(bing)在植株生(sheng)(sheng)長(chang)中(zhong)后(hou)期發生(sheng)(sheng)嚴重(zhong)，主(zhu)要危害(hai)(hai)莖(jing)、葉(xie)和果(guo)(guo)實(shi)(shi)，受(shou)侵染(ran)的(de)果(guo)(guo)實(shi)(shi)采收后(hou)在貯(zhu)運過程(cheng)中(zhong)，遇(yu)潮濕(shi)環境(jing)會腐爛，不堪食(shi)用(yong)。病(bing)(bing)(bing)(bing)苗(miao)子(zi)葉(xie)邊緣出(chu)現半(ban)圓(yuan)(yuan)形(xing)褐色(se)(se)(se)病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)。幼莖(jing)病(bing)(bing)(bing)(bing)部黑(hei)(hei)褐色(se)(se)(se)，并縊(yi)縮(suo)，瓜(gua)苗(miao)易死亡，成株期葉(xie)片發病(bing)(bing)(bing)(bing)呈(cheng)黑(hei)(hei)色(se)(se)(se)或紫(zi)黑(hei)(hei)色(se)(se)(se)有同心輪紋(wen)圓(yuan)(yuan)斑(ban)(ban)(ban)(ban)(ban)。病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)處易開裂(lie)(lie)、破碎。瓜(gua)蔓或葉(xie)柄受(shou)害(hai)(hai)，產生(sheng)(sheng)紡錘形(xing)黑(hei)(hei)色(se)(se)(se)稍凹(ao)陷(xian)病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)。果(guo)(guo)實(shi)(shi)受(shou)害(hai)(hai)，初為(wei)暗(an)綠色(se)(se)(se)水(shui)漬(zi)狀圓(yuan)(yuan)形(xing)小斑(ban)(ban)(ban)(ban)(ban)，逐漸擴大呈(cheng)暗(an)褐色(se)(se)(se)凹(ao)陷(xian)的(de)大斑(ban)(ban)(ban)(ban)(ban)。在潮濕(shi)環境(jing)下，病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)上溢出(chu)粉(fen)紅色(se)(se)(se)黏稠物(wu)，生(sheng)(sheng)有病(bing)(bing)(bing)(bing)菌的(de)分生(sheng)(sheng)孢子(zi)堆，病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)干涸后(hou)常呈(cheng)星狀開裂(lie)(lie)。嚴重(zhong)時病(bing)(bing)(bing)(bing)斑(ban)(ban)(ban)(ban)(ban)連成一片，使(shi)果(guo)(guo)實(shi)(shi)腐爛。病(bing)(bing)(bing)(bing)菌隨病(bing)(bing)(bing)(bing)殘(can)體在土壤中(zhong)或種子(zi)上越冬。分生(sheng)(sheng)孢子(zi)借風、雨、流水(shui)、昆(kun)蟲和人畜(chu)活動傳(chuan)播。高濕(shi)是誘發本(ben)病(bing)(bing)(bing)(bing)的(de)重(zhong)要因素，降雨多的(de)年份(fen)，溫(wen)度在20～24℃時，植株生(sheng)(sheng)長(chang)茂密，發病(bing)(bing)(bing)(bing)最(zui)盛。

防治方法：播種前種子消毒或用(yong)藥(yao)劑(ji)拌種。實行3～5年的輪作。選排(pai)水良(liang)好的地塊種植，高畦栽培(pei)，增施磷、鉀肥。藥(yao)劑(ji)可(ke)選用(yong)80％代森鋅800倍(bei)液(ye)或70％甲基(ji)托布津1000倍(bei)液(ye)、75％百菌清可(ke)濕性(xing)粉劑(ji)500～600倍(bei)液(ye)噴布。