Abstract
Four to $17\%$ of the seeds of ginseng (Panax ginseng Meyer) collected from seemingly healthy plants carried Colletotrichum panacicola Nakata et Takimoto whereas the seeds from the plants with anthracnose sympotoms carried $42\%$ of the same fungus. Prevalent organisms isolated other than C. panacicola from seeds of both kinds of plants were Fusarium, Alternaria, Phoma, Trichoderma and others, ana in that order on acidified potato sucrose agar. C. panacicola also was isolated from 18 months old herbarium specimens. The fungus in the infected tissues also survived during the Korean winter months either on the soil surface or in the soil at 10 and 30 em in depth. When conidial suspensions of C. panacicola were inoculated on detached ginseng leaves, anthracnose symptoms occurred from 25 to $35^{\circ}C$. No symptoms occurred at temperatures below $17^{\circ}C$. Direct sunlight increased significantly the number of anthracnose lesions over those obtained in leaves inoculated in darkness or in 400 lux of fluorescent light. The lesions decreased as age of the leaves increased or as the number of conidia applied decreased. Optimum temperature for mycelial growth and conidial formation of C. panacicola was $25^{\circ}C$. Optimum pH for the mycelial growth was at $pH\;2.8\~4.6$ while the most conidial formation occurred at $pH\;5.2\~5.8.$. When fungicides were applied in the field to ginseng plants with a conidial suspension of C. panacicola, the most effective control of the anthracnose disease was by spraying with difolatan, and followed by maneb, zineb, captan and phaltan; Bordeaux mixture and ferbam were significantly less effective but significantly better than the inoculated control plants.
인삼탄저병에 감염된 포기의 종자에는 $42\%$, 겉으로 건전한 포기의 종자에도 $4\~17\%$의 탄저병균을 보유하고 있었으며, Fusarium, Alternaria, Phoma, Trichoderma 등도 많이 분리되었다. 탄저병균은 실내에 있는 잎의 조직에서 18개월간 생존하였으며, 옥외의 노지, 지하 10, 30cm에서도 월동할 수 있었다. 인삼잎에 탄저병균의 분생자를 접종하였을 때에 $25-35^{\circ}C$ 발병하였고, $17^{\circ}C$이하에서는 전혀 병반이 형성되지 않았다. 암흑구, 400룩스구에서 탄저병반은 미소하였고, 1200룩스구에서 중정도, 직사광선에서는 극심하였다. 그리고 연령이 어린 잎일수록, 분생자수가 많을수록 병반면적율은 높았다. 병원균의 균사생장 및 분생자형성의 최적온도는 $25^{\circ}C$였고, 균사생장의 최적 pH는 2.8-4.2였으며 분생사형성은 5.2-5.8이었다. 포장에서 살균제와 인삼${\cdot}$탄저병균의 분생자를 함께 3년생식물에 처리했을 때 방제효과가 큰 것은 difolatan 그리고 maneb, zineb, captan, phaltan의 순위였으며 ferbam과 보르도액은 약간 낮았다.