Interaction of root- knot nematode (Meloidogyne javanica) and bacterial agent of common scab (Streptomyces scabies) on potato

Causal agent of common scab and root knot nematodes are important pathogens of potato. Each of two pathogens alone are causing considerable damage to product. In order to study interaction of two pathogens, inoculation of potatoes (Agria cv.) by bacteria (S. scabies) and nematode (M. javanica) alone and combination both agents at different time were carried out in greenhouse in a completely randomized design with seven treatments and six replications. Bacterial inoculums were mixed with pot soil (2% w/w) and 10000 nematodes (egg and juvenile) added to each pot. Results of analyze variance and comparison of means were showed significant difference in the most pathogenisity indices and growth parameters between different treatments. Inoculation of plants by bacterium or nematode alone were reduced some of indices growth compare to control. Plants growth inoculated with both pathogens were also decreased than to control and bacteria-infected plants however, did not have significant difference with nematode-infected plants. Nematode population in soil and root of infected plants by both pathogens were low. In other word, the bacterium was caused reduction in pathogenisity of nematode. Wound in inoculated plants by two pathogens were increased than to inoculated plants by bacteria alone.