FIRE BLIGHT CONTROL WITH STREPTOMYCIN ACCORDING TO PREDICTION SYSTEMS IN SOUTH-WEST GERMANY

E. Moltmann
Due to a heavy outbreak of fire blight in 1993 in South-West Germany, streptomycin has been allowed to be sprayed during bloom of apple and pear since 1994. In order to minimize the number of applications, the plant protection service has been instructed by the government to announce infection risk days when spraying is necessary. The prediction systems MaryblytTM, Billing's Revised System and Billing's Integrated System 95 are used. In some years infection risk days were indicated which lead to heavy infections in those orchards not sprayed at the recommended time. In other years, however, infection risk days were indicated but no infections occurred. On the other hand it has been proved, that the systems never failed to indicate infection risk days when infections took place. The incidence of Ewinia amylovora strains resistant to streptomycin has been monitored since 1996. So far, no resistant strains have been detected. In field experiments, alternative compounds to streptomycin (Mycosin, BionTM, and BlightBanTM A506) were tested. In order to obtain natural infections, single trees in the plots were sprayed with a suspension of Erwinia amylovora. Only the neighbouring trees infected by secondary spread of the bacterium were evaluated. The efficacy of none of the tested compounds was comparable to streptomycin.
Moltmann, E. (1999). FIRE BLIGHT CONTROL WITH STREPTOMYCIN ACCORDING TO PREDICTION SYSTEMS IN SOUTH-WEST GERMANY. Acta Hortic. 489, 393-398
DOI: 10.17660/ActaHortic.1999.489.68
https://doi.org/10.17660/ActaHortic.1999.489.68
Billing's Revised System, Billing's Integrated System 95, BIS 95, MaryblytTM, resistant strains, Mycosin, BionTM, Blight BanTM A506

Acta Horticulturae