Identification of Fungi Allied with the Rot of Unripe Pepper (Capsicum annuum) Grown in Wukari, Taraba State, Nigeria

摘要

The research investigation of fungi associated with the rot of unripe pepper Capsicum annuum was carried out using fifty (50) of unripe pepper Capsicum annuum samples from four (4) different farm sites spread across Wukari town. Isolation of the isolates was done using standard microbiological techniques with Potato Dextrose Agar (PDA) and incubating at room temperature (28 ± 2°C) for up to 14 days. Five (5) different fungi were isolated from the rotted fruits, which were Aspergillus niger, Aspergillus fumigatus, Aspergillus nidulans, Penicillium species and Fusarium oxysporum. In terms of number of isolates and percentage frequency of isolates, Aspergillus niger 7 (25.9%), Aspergillus fumigatus 5 (18.5%), Aspergillus nidulans 4 (14.8%), Penicillium species 1 (3.7%) and Fusarium oxysporum 10 (37%). Among these isolates Fusarium oxysporum 10 (37%) had the highest frequency of occurrence while Penicillium species 1 (3.7%) had the lowest frequency of occurrence. Fusarium oxysporum, Aspergillus niger, Aspergillus fumigatus caused the soft rot of unripe pepper fruits after 48 hours incubation when pathogenicity test of the isolates was done using fresh and well sterilized unripe pepper Capsicum annuum. On the other hand, Aspergillus nidulans and Penicillium species did not cause soft rot of the unripe pepper. In conclusion, the immediate practical measure of reducing spoilage may be by educating the farmers and traders on proper handling methods of these fruits as the major factors noted in the course of this study to be responsible for the spoilage was due to wounds, cuts and bruises of the fruits. Each of the wounds served as an entrance for the various soft rot pathogens and associated microorganisms. Also, some fruits carry several destructive pathogens that manifest themselves in the storage thus leading to the reduction in the market value of the product. To this end, the control of fruit rot should include the use of chemicals in the field and after harvest as these will helps to maintain the quality of fruits during growth, harvest and storage. Also, use of resistant varieties in the propagation of the fruit can also help and the soil should be tested and treated if found to have any pathogen that could affect the fruit after planting. The appropriate application of these suggestions will greatly reduce the losses and provide a better supply of high quality and affordable products of Capsicum annuum.