单 位：
北京农业大学中国科学院真菌植病研究室河北省沙嶺子农业试验站
摘 要：
從馬鈴薯的開花期起可能在田间出现的晚疫病中心病株是本田當年病害即將大量發生的重要標誌。每次再侵染的潛育期,在張家口壩下地區的氣候下,大約4天。從病害的最初發現到全面枯死所經過的日期囚種種外界環境條件而有很大的差別,我們所觀察到的是18—42天。根據調查资料來推測,一方面,促進病菌孢子形成数量和侵入數量的雨水,另一方面,决定植株衰老速度的栽培條件,是這種差別的主要原因。田間再侵染所形成的病斑之分佈情况說明病菌孢子的傳播与風向有直接的關係。估計90%以土的孢子落在中心病株附近順着風向的800平方米的長方形面積上。根據馬鈴薯地上部吸收銅素以提高共抗病力的可能性,利用0.1—0.2%硫酸銅溶液作為噴射劑,在田间中心病株發現的時期開始每隔7—10天喷射共2—3次,可以顯著地降低晚疫病的為害,提高產量。這個方法在共效驗及穩定性上不如波爾多液,在藥劑費用的節省及施用的方便上則勝之?椒ǖ母牧己吞岣哒谶M一步研究中。
译 名：
FIELD OBSERVATIONS ON THE EPIPHYTOLOGY AND EXPERIMENTS ON THE CONTROL OF POTATO LATE BLIGHT
作 者：
C.K.LIN,H.HWANG,K.T.WANG,S.H.HWO,T.P.WANG
摘 要：
Occurrence of sporadic diseased plant centers during or after the bloomingperiod is considered as reliable indication of the current year's forthcomingoutbreak of late blight in a potato farm. Incubation period of each secondary infection being about 4 days,is ratherconstant during the blight epiphytotic season under Chahar conditions.The timeinterval between the appearance of initial diseased plant centers to final totalblight in a potato field varies greatly,however,not only from locality to localitywith different climatic conditions but also from field to field under similarclimatic conditions.Our data record a range of 18-42 days.Circumstantial eviden-ces indicate that this variation is due,on the one hand,to the rainfall whichinfluences the amounts of sporulation and the frequency of penetration of thepathogene,and on the other hand,to cultural and other factors that determinethe vigor and the rate of aging of the plant itself. Actual counts of lesions formed from secondary infection in the early periodof the spread of the disease in a potato field,reveal that their distribution bearsdirect relation with the direction of the prevailing wind.It is estimated that over90% of spores fall within a rectangle of 800 sq.m.around a diseased plantcenter along the loci of wind directions. On the basis of possible function of absorbed copper ions in the enhancementof plant resistance to late blight,field experiments have been conducted by using0.1 - 0.2% copper sulfate solutions as spray.Results show that spraying 2-3 timesat 7-10 days' interval,started soon after the appearance of diseased plant center,gives remarkable control of late blight and corresponding reduction of loss inyield.The copper sulfate spray,though less effective and stable in comparisonwith the bordeaux spray,has the advantage of being more economical and easierto apply.Further experiments with the pu:pose of modifying and improving themethod are in progress.
