Assessing the Resistance of Three Tomato Varieties to Bacterial Wilt and Stem Rot

The aim of this study was to compare the level of resistance of two new hybrids (F1 Nadira and F1 Jaguar) with the popularly known variety Rio Grande against Pseudomonas solanacearum (causal agent of bacterial wilt) and Erwinia carotovora (responsible of stem rot) under natural conditions. A randomized sample block design containing three treatments (F1 Nadira, F1 Jaguar and Rio Grande) with three repetitions was used. The research took place in Obala subdivision and in University of Yaounde 1, Faculty of Science, Department of Plant Biology, laboratory of Phytopathology and Microbiology in Cameroon during the 2010-2011 growing seasons. The resistance of each variety to the two bacterial diseases was assessed by determining incidence and severity of the diseases. Bacterial symptoms on tomato were identified by visual diagnostic. The incidence and severity of P. solanacearum ranged between 27-39% and 86-92% respectively on all tomato varieties tested; the hybrid F1 Jaguar proved to be less susceptible to bacterial wilt than the control Rio Grande. All the varieties tested had a similar susceptibility with incidence and severity up to 45 and 80% respectively, to E. carotovora. Overall, no significant differences on disease incidence were observed for the two diseases tested. However, the difference in yield between the tested varieties appears to be high. We recommend the use of the hybrid varieties based on their higher production potential of larger fruits and low disease incidence.