Susceptibility of Cyphomandra betacea to Pseudomonas solanacearum. Carlos Martin, Pathology Department, International Potato Center, Apartado 5969, Lima, Peru. Ursula Nydegger, Pathology Department, International Potato Center, Apartado 5969, Lima, Peru. Plant Dis. 66:1025-1027. Accepted for publication 16 February 1982. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-1025.

Seventy-day-old seedlings of tree tomato (Cyphomandra betacea) were inoculated through soil infestation and into the stem with 13 strains of Pseudomonas solanacearum from six countries and isolated from six different host species. All three races and the four biotypes of the bacterium were included. In infested soil, only biotypes I and II, which were isolated from potato and tomato, caused tree tomato plants to wilt. When plants were stem inoculated, all four biotypes caused wilt. A strain isolated from Heliconia sp. (banana) did not induce wilting by either inoculation method. An increase in temperature from 22 to 32 C increased the percentage of wilted plants. When larvae of the root-knot nematode (Meloidogyne incognita acrita) were introduced together with P. solanacearum into the soil, the percentage of wilted tree tomato plants increased substantially.

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