Archives

Bacterial canker (Clavibacter michiganensis subsp. michiganensis) of tomato (Solanum lycopersicum) is a newly emerging bacterial disease in mid hills of Himachal Pradesh, India. The disease is causing huge losses to the tomato production in this region. Under the present investigations, the bacterial canker pathogen was isolated in pure culture. For inculcation of bacteria in young tomato plants for pathogenicity testing and germplasm screening, methods like syringe inoculation of leaves and branches, leaf clipping and stem inoculation with toothpick were adjudged effective. Out of 18 tomato lines/ cultivars tested against the pathogen, none was found resistant to the disease after artificial inoculation in pot culture. However, seven lines viz., EC – 521086, EC – 521074, EC – 251649, EC – 25265, EC – 521054, EC – 35322 and EC – 2791 exhibited moderately susceptible reaction and rest of the lines/ cultivars were either susceptible or highly susceptible. Among five bacterial biocontrol agents tested against the bacterial pathogen in vitro, Pseudomonas flourescens strain PfS-1 was found effective in inhibiting the growth of the pathogen. This biocontrol agent when inoculated through seed, improved germination and delayed the expression of disease symptoms in pot culture.
Keywords: Bacterial canker of tomato, disease management, biological control, germplasm screening