The 2011 ASHS Annual Conference

Erwinia amylovora causes fire blight, one of the most destructive diseases that treaten pome fruits globally, and it also affects a wide variety of Rosaceae as well as ornamentals. The disease develops as blossom, shoot, or rootstock blight depending on the plant tissues infected and each syndrome requires specific control strategies. To achieve optimal control of the disease, a program was performed on 4 year-old apple cvs. ‘Gala’ and ‘Fuji’ cultivated on ‘M9’ rootstock on a well drained soil (pH=6.5) having adequate organic matter in 2009 and 2010. Initially, the trees were prunned to remove cankers and sprayed with a copper compound in the winter and second time attentive pruned and then sprayed with Bordeaux mixture (2%) before buds opens in the late winter. A well-balanced and properly planned nutrition program was applied to experimental plants and weeds were mowed. A formulation containing Pantoea agglomerans was sprayed at first 15-20% bloom and second 7 days later. Prohexadione-Ca was applied at a rate of 125 mg L^-1 at two separate shoot length times (6-12 cm and 15-20 cm). Apple tree shoots were inoculated with E. amylovora Ea63 by cutting from the tips of the two newest unfolded leaves on each shoot using a scissors dipped in the bacterial suspension (10⁸ cfu ml^-1). Disease severity was calculated by measuring the proportion of the length of the blighted part of the shoot to the whole length of the shoot (cm). Especially, sucking-piercing insects were controlled by a proper spraying programme. The integrated management approach with all the different factors involved in fire blight management yielded highly successful results about %75. The use of prediction models taking into consideration appropriate timing and climatical factors are essential to control and limit the spread of fire blight disease.