STRATEGY FOR FIRE BLIGHT CONTROL (ERWINIA AMYLO VORA (BURR.) WINSLOW ET AL.) UNDER NATURAL INFECTION CONDITIONS

In orchard trials (pear cv. Durondeau on quince A, adult trees) the effect of combination of the use of chemical compounds (Copac E, Streptomycin, MBR 10995) and cultural measures is discussed : pruning the secondary blossoms, limiting the growing period of the shoots in the season and avoiding regrowth reactions later in the season.

The results indicate that chemicals give control of fire blight but optimal control is only achieved when they are combined with measures to reduce bacterial inoculum by eliminating all diseased plant material and with some cultural measures to reduce the host susceptibility.

In preliminary trials, the efficiency of different chemical compounds against fire blight in comparison with Streptomycin was examined in greenhouse experiments, with artificial inoculation of Erwinia amylovora on growing shoots of young trees of the pear cultivar Durondeau on quince A rootstock.