ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 61 Number 3
Benomyl tolerance in a strain of Penicillium sclerotigenum infecting yams and the use of imazalil as a means of control
A benomyl-tolerant isolate of Penicillium sclerotigenum was obtained from sea-freighted Jamaican yellow yam. Growth of the fungus on an amended potato dextrose agar medium decreased exponentially as the concentration of benomyl was increased. Although the pathogen could be grown on a medium containing 1000 mg dm-3 of this fungicide, imazalil at a concentration of 10 mg dm-3caused complete inhibition. On yam tissue, the reduction of temperature from 25 to 14°C caused a decrease in growth which was further enhanced by treatment with benomyl, but the area of decay continued to increase with storage time. Treatment of inoculated yam with benomyl resulted in reduced lateral growth of the fungus but increased penetration. This effect was more pronounced at 20ºC than at 14°C. Treatment with imazalil at 500 or 1000 mg dm-3 completely inhibited decay over a period of 28 days storage at 20°C.
Keywords: Yams; Penicillium sclerotigenum; Fungal diseases