FIELD SUSCEPTIBILITY TO FIRE BLIGHT OF POME FRUITS IN BULGARIA

Observations were carried out in two experimental orchards located in Plovdiv region during three consecutive years.
The values of fire blight severity (USDA-scale) registered in 1994/95 seasons on pear cultivars, subsequently transformed to five resistance/susceptibility categories showed that Bella di Giugno and Beurre Giffard came under the resistant categories, Cure was defined as intermediate to moderately susceptible, and B. Hardenpont – as moderately susceptible.
The quince cultivars Hemus and Triumph (resistant), and Asenitza (moderately to very susceptible), respectively outlined the extremes of the host response, whereas Du Portugal took an intermediate position.
The severe spring damages in both orchards (1996) confirmed in general the rates of the cultivars obtained in the previous years.
Under the circumstances (second orchard) Beurre Hardenpont and Du Portugal were also defined as very susceptible to blossom infections, and the latter also as susceptible to hail trauma infections.
After the first outbreak of fire blight on apple, no damages were observed in Cooper 4 and Starkrimson, one infection per tree in Golden Delicious, and more than one in Belgolden (1.6), Granny Smith (2.8), Vista bella (3.5), Melrose (4.4), Prim rouge (6.7), and Mutsu (7.9).

VIII International Workshop on Fire Blight

S. Bobev, T. Deckers

E. amylovora, quince, pear, apple

https://doi.org/10.17660/ActaHortic.1999.489.34