FURTHER EXPERIMENTS TO CONTROL FIREBLIGHT IN THE FEDERAL REPUBLIC OF GERMANY
Experiments to control fireblight with different bactericide compounds (antibiotics, copper compounds, synthetic organic substances, disinfectants) have been carried out in the Federal Republic of Germany. Additionally, biological control experiments with strain Y 112 of Erwinia herbicola and another antagonist were undertaken. The highly susceptible ornamental shrub Cotoneaster floccosus was used as the host plant in most experiments; the pear variety 'Conference' and a pear rootstock were also used. Spraying against blossom and shoot blight, under natural and artificial infection conditions, was carried out at three different locations in the country. The best control effect was found with the experimental compound CGD 93600 B from CIBA GEIGY, with more than 90 % degree of control in protective and curative treatments. In comparison, the effectiveness of copper compounds ranged between 50 and 80 %, whereby a new experimental compound with a low copper concentration, LAB 002828 F, gave the best results. As CGD 93600 B will not be produced in the future due to toxilogical aspects, this new copper substance could be an alternative.
Zeller, W., Maβfeller, D. and Krebs, E. (1984). FURTHER EXPERIMENTS TO CONTROL FIREBLIGHT IN THE FEDERAL REPUBLIC OF GERMANY. Acta Hortic. 151, 165-172