Susceptibility of stone-fruit rootstocks, rose and grapevine to Agrobacterium radiobacter var. tumefaciens in Arab Mediterranean countries.

Crown gall was found in all fruit-growing areas in Algeria, Jordan, Morocco and Tunisia. In the last three countries, shoot and/or root inoculation of stone fruits, rose and/or grapevine (according to country) with Agrobacterium radiobacter var. tumefaciens showed that all species were susceptible independently of country and origin of bacterial strains, with the exception of the Beldi land race of apricot in Morocco, which was tolerant. The level of susceptibility varied according to the strains used.