特性：屬(shu)真菌性病(bing)(bing)害(hai)，洋(yang)香瓜(gua)炭疽病(bing)(bing)在(zai)(zai)植株(zhu)生(sheng)長(chang)中(zhong)后(hou)期發(fa)(fa)(fa)生(sheng)嚴(yan)重(zhong)，主(zhu)要危害(hai)莖(jing)、葉(xie)和(he)果(guo)(guo)實，受侵染的(de)果(guo)(guo)實采收(shou)后(hou)在(zai)(zai)貯運過程中(zhong)，遇(yu)潮(chao)濕環境會腐爛(lan)，不堪食(shi)用。病(bing)(bing)苗子葉(xie)邊緣出(chu)現(xian)半圓(yuan)形(xing)褐色(se)病(bing)(bing)斑(ban)(ban)(ban)(ban)。幼(you)莖(jing)病(bing)(bing)部(bu)黑褐色(se)，并(bing)縊(yi)縮，瓜(gua)苗易死亡，成(cheng)株(zhu)期葉(xie)片發(fa)(fa)(fa)病(bing)(bing)呈(cheng)黑色(se)或(huo)紫黑色(se)有同(tong)心(xin)輪紋圓(yuan)斑(ban)(ban)(ban)(ban)。病(bing)(bing)斑(ban)(ban)(ban)(ban)處(chu)易開裂(lie)、破碎。瓜(gua)蔓或(huo)葉(xie)柄受害(hai)，產(chan)生(sheng)紡錘形(xing)黑色(se)稍(shao)凹陷病(bing)(bing)斑(ban)(ban)(ban)(ban)。果(guo)(guo)實受害(hai)，初為暗綠(lv)色(se)水漬狀圓(yuan)形(xing)小斑(ban)(ban)(ban)(ban)，逐漸擴大呈(cheng)暗褐色(se)凹陷的(de)大斑(ban)(ban)(ban)(ban)。在(zai)(zai)潮(chao)濕環境下(xia)，病(bing)(bing)斑(ban)(ban)(ban)(ban)上(shang)溢出(chu)粉紅(hong)色(se)黏稠(chou)物，生(sheng)有病(bing)(bing)菌的(de)分(fen)生(sheng)孢子堆，病(bing)(bing)斑(ban)(ban)(ban)(ban)干涸(he)后(hou)常(chang)呈(cheng)星狀開裂(lie)。嚴(yan)重(zhong)時(shi)病(bing)(bing)斑(ban)(ban)(ban)(ban)連成(cheng)一片，使(shi)果(guo)(guo)實腐爛(lan)。病(bing)(bing)菌隨病(bing)(bing)殘體在(zai)(zai)土壤中(zhong)或(huo)種子上(shang)越冬。分(fen)生(sheng)孢子借風(feng)、雨、流水、昆蟲和(he)人畜活動傳播(bo)。高(gao)濕是(shi)誘(you)發(fa)(fa)(fa)本病(bing)(bing)的(de)重(zhong)要因素，降雨多的(de)年份(fen)，溫度在(zai)(zai)20～24℃時(shi)，植株(zhu)生(sheng)長(chang)茂密(mi)，發(fa)(fa)(fa)病(bing)(bing)最盛。

防治方法：播種(zhong)前種(zhong)子消(xiao)毒或(huo)用藥(yao)(yao)劑(ji)拌種(zhong)。實行3～5年(nian)的(de)輪(lun)作。選(xuan)排水良好(hao)的(de)地(di)塊種(zhong)植(zhi)，高(gao)畦栽培，增施磷、鉀肥(fei)。藥(yao)(yao)劑(ji)可選(xuan)用80％代(dai)森鋅(xin)800倍液或(huo)70％甲基托(tuo)布津1000倍液、75％百菌(jun)清可濕性粉劑(ji)500～600倍液噴布。