One is to strengthen the prevention and control measures of cultivation and management, transplanting to soil, reduce the damage to roots, soil moisture conservation irrigated after planting, and scaffolding shade. But also in the process of handling and transporting seedlings to avoid hurting the stem, otherwise, easy cause infection. Before transplantation, if found to decay, application of chlorothalonil or thiophanate sterilization. 病蟲(chóng)測(cè)報(bào)燈對(duì)蘇鐵病蟲(chóng)害的防治措施 蘇鐵病蟲(chóng)害發(fā)病癥:狀斑點(diǎn)病表現(xiàn):發(fā)病初期葉片出現(xiàn)淡褐色小點(diǎn),并逐漸擴(kuò)大為圓形或不規(guī)則形的病斑,邊緣紅褐色至灰白色。后期病斑上散生或聚生黑色小粒點(diǎn)。病重時(shí)病斑可連接成大斑,造成葉片上部枯死。白斑。喝~上病斑長(zhǎng)形不規(guī)則,多由葉尖向下擴(kuò)展,病斑中央灰白色,邊緣紅褐色或紫紅色,上生小黑點(diǎn),病斑多從羽狀葉尖端向下發(fā)展,病斑連接可使羽狀葉成段枯干或全株枯死。炭疽。涸摬〕0l(fā)于葉片,引起小葉成段或整個(gè)枯死,病部著生黑色小點(diǎn),潮濕時(shí),小黑點(diǎn)上可分泌出粉紅色的膠狀物。根端腐爛。罕缓μK鐵植株根部壞死腐爛;有時(shí)有臭味,嚴(yán)重時(shí)可造成全株干枯死亡。 發(fā)病規(guī)律斑點(diǎn)病、白斑病、炭疽病三種病原菌均在病葉上危害、越冬。高溫多雨的氣候條件、栽培土貧瘠黏重、栽培環(huán)境通風(fēng)透光性差等條件,均易導(dǎo)致病害的嚴(yán)重發(fā)生。盆栽蘇鐵若放置在光照較強(qiáng)的水泥地上,會(huì)加重斑點(diǎn)病和白斑病的危害程度。冬季防寒措施不好,化凍后的蘇鐵容易發(fā)生炭疽病。危害較重的時(shí)期為8至9月,每年的5至11月均有發(fā)生,土質(zhì)黏重并長(zhǎng)期漬水潮濕的情況下,易誘發(fā)根端腐爛病。 防治措施一是加強(qiáng)栽培管理,移栽時(shí)宜帶土,盡量減輕對(duì)根系的損傷,定植后澆透水保持土壤濕潤(rùn),并搭棚遮蔭。在裝卸運(yùn)苗過(guò)程中也要避免傷及干莖,否則,易導(dǎo)致病菌侵入。在移植前,若發(fā)現(xiàn)腐爛部分,應(yīng)用百菌清或托布津消毒殺菌。莖干與土壤消毒徹底與否,是移栽成敗的關(guān)鍵,種植蘇鐵的土壤要疏松肥沃,盆栽的要避免盆土積水,地栽的要避免栽在低洼積水處。新葉展開(kāi)時(shí),應(yīng)將植株下部有病的老葉、病枝清除,放置環(huán)境應(yīng)保持通風(fēng)和光照充足,夏季噴清水。在冬季嚴(yán)寒地區(qū)應(yīng)及早采取防寒措施,避免植株遭受凍害,以增強(qiáng)蘇鐵生長(zhǎng)勢(shì)提高抗病能力,減少侵染來(lái)源。二是及時(shí)進(jìn)行藥劑防治。蘇鐵斑點(diǎn)病和白斑病可在發(fā)病初始階段用炭福美500倍液或50%多菌靈或托布津500至1000倍液噴灑,噴灑時(shí)加入0.1%洗衣粉為粘合劑,效果更好,隔7至10天噴灑1次。防治蘇鐵炭疽病,可選用70%炭疽福美500倍液噴灑,對(duì)蘇鐵根端腐爛病,發(fā)現(xiàn)病株后,應(yīng)立即清除腐根及周?chē)鷰Ь寥,土壤消毒?0%福爾馬林,或70%五氯硝基苯與80%代森鋅粉劑混合后消毒