The reaction of pear cultivars grafted on pear and quince rootstocks after artificial inoculation of Erwinia amylovora

Fire blight caused by Erwinia amylovora is one of the most dangerous bacterial diseases for pear orchards and has to be reported to the authorities for tree eradication.
Different strains of Erwinia amylovora show variation in their virulence.
The reaction on hosts depends on different susceptibility of cultivars and rootstock to fire blight.
This study aimed to evaluate the effect of E. amylovora strains on own rooted pear trees and cultivars grafted on a quince and pear rootstocks after artificial inoculation.
Leaves of the from pear cultivars ‘Beurre Bosc’, ‘Williams’, ‘Red Williams’, ‘Packham’s Triumph’ and ‘Abate Fetel’ grafted on rootstocks – BA29 (quince) or, OHF 333 (pear), were artificial inoculation using two strains of Erwinia amylovora alone or in combination.
The best results in leaves infection with the lowest percent of infection occurred on cultivars grafted on pear rootstock OHF333. The leaves of Red Williams grafted on OHF 333 showed 10.8% necrosis, the same cultivar grafted on BA29 showed 69.9% infected leaves and the own rooted trees showed 65.9% damage.
The pear cultivar ‘Williams’ grafted on OHF 333 had 6.33% infected shoots 25 days after inoculation, while the necrosis in other combinations was over 20%.

IV International Symposium on Horticulture in Europe – SHE2021

D. Aleksandrova, N. Dimitrova

fire blight, strain, OHF 333, BA29, pear, quince

https://doi.org/10.17660/ActaHortic.2021.1327.43