Abstract

A field survey experiment was conducted at Umuahia North, Umudike, Abia State and Okigwe, Imo State, South Eastern Nigeria to assess the occurrence of bacterial soft rot disease of cucumber (Cucumis sativum L.) Diseased fruits were taken to the laboratory for examination, isolation and identification of micro-organisms, and the observed causal organism was Pectobacterium carotovorum. Field experiments were conducted at the Research Farms of the National Horticultural Research Institute (NIHORT) Okigwe and Michael Okpara University of Agriculture, Umudike (MOUAU) from June to August 2017 cropping season, to determine the efficacy ofleaf extracts ofBryophyllumpinnatum, Ficus sur, andJatropha curcas in the control of bacterial soft rot disease of cucumber and on yield performance. The experimental design was Randomized Complete Block Design (RCBD) replicated three times; treatments used were the leaf extracts of Bryophyllum pinnatum, Ficus sur, Jatropha curcas, streptomycin (antibiotics) served as a positive check while sterile water served as the negative control. Three varieties of cucumber used include Beta alpha, Marketer and Ngwa Local. Seeds were sown on a 6m ridge at Im x Im spacing. The result showed that fruit rot can initiate from the 6th week after planting increasing till harvest; and disease symptoms develop and become more pronounced after long period ofrainfall (304.0mm and 402.6mm) and high humidity (80% and 85%). Result showed that all the leaf extracts assessed significantly (P<0.05) reduced the disease incidence and severity at NIHORT and MOUAU when compared with the control which recorded 60%, 3.2 and 62.20, 3.76 respectively. Leaf extract of Ficus sur had the best performance in yield at Umudike (18.56t/ha), and compared favourably with streptomycin treated plants which recorded 1.24, 22.20% and 1.24, 20% in reducing disease severity and incidence at NIHORT and MOUAU respectively. It is therefore recommended that biopesticides of Bryophyllum pinnatum, Ficus sur, and Jatropha curcas be used as a better alternative to synthetic pesticide in the management of bacterial soft rot of cucumber in South Eastern Nigeria.