Abstract
The fifty percent effective concentration (EC50) and the minimum inhibitory concentration (MIC) of iprodione on the resistant isolates of Alternaria mali obtained from infected leaves in Kyeongsan region ranged $550\~1,310{\mu}g/ml$ and $33,800-39,800{\mu}g/ml$, respectively. Conidia germination of the resistant isolates reached $70\%$ on PSA added with iprodione, $500{\mu}g/ml$ When treated with $500{\mu}g/ml$ iprodione soon after the inoculation the diameters of lesions on apple fruits 7days after inoculation with the resistant isolates were 1.6-14.6mm but no lesions appeared on those inoculated with the sensitive isolates. A similar trend of responses with the sensitive isolates was shown to benomyl, chlorothalonil, garbenda, thiophanatemethyl and triademefon with the resistant isolates. One isolate among the resistant ones was cross resistance to captan and folpet that were effective to the sensitive isolates.
울산지방의 농가과수원 사과나무 나병엽에서 분리한 Alternaria mail Roberts의 iprodione 저항성균주의 EC50은 $550\~1,310{\mu}g/ml$였다. 포자발아율은 iprodione $500{\mu}g/ml$를 가한 PSA에서 $70\%$였다. 저항성균주를 접종한 사과에 동약제 $500{\mu}g/ml$ 용액을 처리하였을 때 7일후 병반직경이 1.6-14.6mm였으나 감수성균주는 0mm였다. Benomyl, Chlorothalonil, garbenda, thiophanatemethyl 및 triademefon에 대해서는 이들 저항성균주가 감수성균주와 비슷한 경향의 반응을 보였으나 저항성균주 $R_3$는 밤수성균주에 효과적인 captan과 folpet이 대하여 교착저항성을 나타내었다.