The most important characteristic related to high CBB severity was plant age, with old plants being more diseased than younger plants. CBB was more severe in loamy soils and in monocultures and single varietal plantings than in intercrops or a mixture of varieties, respectively. A positive relation of CBB severity to the dryer ecozones was observed. WLS appeared to be more frequently found in more humid climates, but also seemed to be suppressed by growing several varieties in one field.