Effectiveness of some plant extracts in the management of tomato pith necrosis caused by Pseudomonas corrugata

Abstract

Three plants extract - Aloe vera, Azadirachta indica and Lawsonia inermis were tested in the laboratory and on the field to establish their effectiveness in the control of Pseudomonas corrugate the causative agent of tomato pith necrosis. Streptomycin and water served as positive and negative control respectively. In-vitro evaluation of plant extracts to control the growth of the pathogen was carried out prior to field application. The water-extract of the plants were sprayed three weeks after transplanting in a randomized complete block design involving five treatments and three replicates. Results showed that Aloe vera extracts led to the least bacterial growth of 11.34x10 cfu/ml. Extracts of Azadirachta indica led to the highest bacterial population of 490.66x10 cfu/ml. Among the three plant materials treated Aloe vera extracts significantly [p<0.05] showed the least disease incidence [40.70%] and severity [38.70%] and water [35.00%] and severity [45.60%]. Similarly, Aloe vera supporrted better vegetative grrowth indices in terrms of number of branches, plant height and stem girth. However, yeld in tomato treated with the three plant extracts did not show statistcally significant differences at p<0.05. the worrk concluded that water extracts at 0.5g/ml of Aloe vera applied as spray at three weeks afterr tranplanting could be used to manage tomato pith necrosis caused by pseudomonas corrrrugata and also as possible alternative to chemical pesticides known to be environmentally unsafe