Interaction between root-knot nematode, Meloidogyne incognita alone and in combination with the bacterium, Ralstonia solanacearum were evaluated on the growth of potato plants cvs. Diamant and Spunta,nematode reproduction and bacteria as well under greenhouse conditions.
Results showed that potato cv. Spunta was highly susceptible to bacterial wilt disease than cv. Diamant. The possible combinations of M. incognita and R. solanacearum revealed that potato plants inoculated with M. incognita 10 days prior to bacterial pathogen’s inoculation showed higher bacterial wilt disease rating than those inoculated with both pathogens simultaneously with values of 3.95 and 3.45, respectively. The higher nematode galling index was noted on potato plants cv. Diamant than cv.Spunta with values of 2.32 and 1.92, respectively.
Results also showed that plants receiving nematodes with bacteria added at the same time, the highest injury of nematode accompanied by the highest rate of build-up that recorded to be 30.83 and 22.15 for potato cvs,Diamant and Spunta, followed by the combination with R. solanacearum 10 days after nematode inoculation that was recorded to be 26.78 and 20.35 for the same potato cultivars, respectively. Moreover, there was a significant reduction in both shoot and root fresh weights of the two tested cultivars infected with either pathogen alone or together.