HOST SUSCEPTIBILITY AS A FACTOR IN CONTROL STRATEGIES OF FIRE BLIGHT IN EUROPEAN PEAR GROWING
The standard fire blight control strategy in many countries is mainly based on one or more treatments during a period when a high climatological risk is combined with a high phenological risk. The primary blossom period is the phenological period with the highest risk for large scale fire blight blossom infection in the orchard. A second high risk period is when a hailstorm damages the young shoots and immature fruitlets in an orchard and an extremely high inoculum can develop as bacterial ooze on their surface within a very short period of a few days. But in many fruit production areas, with a temperate zone climatology, primary blossom periods often escape general fire blight blossom infection and other types of fire blight infections such as secondary blossom infections or shoot infections are more important. Compounds that reduce the vegetative shoot growth can interfere with fire blight shoot infections. Other compounds that interfere with phenol metabolism or with the lignification process in fruit trees can also interfere with the fire blight infections. An important aspect is the timing of these treatments with the aim of switching on the internal defence mechanism of the plants. For secondary blossom protection the treatments can start from the green cluster stage of these late flowers. In some cases there is a rejection by the naturally infected flowers before the infection penetrates into the vascular system of the flowers. Some results with Prohexadione-Ca, Carpropamid and Benzothiadiazole on pear trees are discussed.
Deckers, T. and Schoofs, H. (2002). HOST SUSCEPTIBILITY AS A FACTOR IN CONTROL STRATEGIES OF FIRE BLIGHT IN EUROPEAN PEAR GROWING. Acta Hortic. 590, 127-138
fire blight control, host susceptibility, bacteriocin Serratin-P