INVESTIGATION OF THE RELIABILITY OF EASY-TO-USE METHODS TO PREDICT ERWINIA AMYLOVORA INFECTION RISK IN APPLE ORCHARDS
As a complement to a national fire blight monitoring network, such as the MARYBLYT system in Hungary, an accurate local prediction method would improve control in a large orchard or a micro-region. Data relating to temperature and wetting events in 1999-2001 were analysed by means of the Californian Mean temperature line, Smiths degree hour-based model (Cougarblight), Billings integrated system (BIS95) and the MARYBLYT computer model. In two years, the start of the massive infection risk was predicted by three of four models on the same day: 28 April in 1999 and 25 April in 2000. However, there was a delay of one day with the Cougarblight model as compared with the BIS95 and MARYBLYT systems in 2001. The forecast of an infection risk via the Mean Temperature Line was consequently one day later than that with the BIS95 and MARYBLYT systems. The size of the epiphytic bacterial population in the flowers was variable from year to year, with no convincing difference between cultivars with high (e.g. 'Sampion') or low (e.g. 'Freedom') susceptibility. The incidence of fire blight was sporadic in 1999 and 2001, but epidemic in 2000. The proportion of trees of 6 apple cultivars with fire blight symptoms well reflected the differences in weather-related risks in the two years investigated. The findings indicate that both Cougarblight and BIS95 deserve to be tested in commercial orchards in Hungary.
Bubán, T., Sallai, P., Varga, A. and Dorgai, L. (2002). INVESTIGATION OF THE RELIABILITY OF EASY-TO-USE METHODS TO PREDICT ERWINIA AMYLOVORA INFECTION RISK IN APPLE ORCHARDS. Acta Hortic. 590, 119-125
Malus x domestica, fire blight, Cougarblight, Mean Temperature Line, BIS95, MARYBLYT, epiphytic population