ABSTRACT

The control of yam rot in storage using the leaf extract of Azadirachta indica, Piper nigrum, Vernonia amygdalina and Ocimum basilicum. The experiment was conducted in the Laboratory Department of Plant Science and Biotechnology, College of Natural Sciences, Michael Okpara University of Agriculture, Umudike, Using a Completely Randomized Design. The Yam tubers used were visually classified as having 40% nematode infestations and obtained from the Yam barn of National Root Crops Research Institute (NRCRI), Umudike, Nigeria. Four samples of fresh Yam were also collected from the barn for pathogenicity test. The plant extracts were diluted with tap water at the ratio of 1: 5 ( 1 ml of plant extracts + 5 ml of water) respectively. 150 cl of tap water was thoroughly mixed with 10 ml of each diluted extracts in buckets and the infested yam were soaked for 24 hours. The Yam tubers were removed from the buckets while data on sprouting, Rot and Insects were recorded according to the method of Salawu. The proximate of evaluation of the treated and the untreated tubers were recorded in tenns of Protein, Fibre, Fat, Moisture, Ash, and Carbohydrate contents. The pathogenic results shows that Fungi like Rhizopus, Penicillum, Aspergilus, Fusarium and B. theobrone were the identified rot organism. Sprouting of Yam, treated with different extracts showed that only A. indica ranged from 0.75 ± 0.500 - 1.0 ± 0.00. However the effect of extracts of P. nigrum, V. amygdalina and control had significant effect P <0.05 on the sprouting of Yam tubers. From the means, control treatment ranging from 0.50 ± 0.58 to 0.75 ± 0.58 had the lowest sprouting rate. There was also a significant effect P <0.05 of Water on the Yam rot. The rot affected the carbohydrate. Protein and Fat content of the Yam tuber. Generally the extracts had a strong advantage to the gennination, pathogenicity and Nutritional content of Yam tubers in Storage.