Abstract

Production of red raspberry (Rubus idaeus) and other Rubus cane fruits relies currently in some areas on repeated applications of fungicides to ensure freedom from major diseases, such as grey mould (Botrytis cinerea). With pressure from consumers, large retail outlets and processors for a reduction in fungicide use, growers face some difficult decisions about how best to control diseases, but simultaneously maintain high fruit quality and profitability. The recent expansion of covered cropping and out-of-season production to provide fresh berries when prices are high has also increased the risk of attack by some fungal diseases that previously were of little concern. The expansion of new cane fruit industries in southern countries of Europe, Asia and elsewhere will inevitably expose these industries to the possible import of well-known pathogens with planting material. It may also lead to epidemics of novel pathogens and pests of raspberries and blackberries arising from local reservoirs of inoculum in wild Rubus spp. Being long-lived woody perennials with a biennial cane habit, raspberries and other cane fruits tend to accumulate fungal inoculum as plantations age. Unless high quality, disease-free stocks are used for crop establishment and rigorous control measures are imposed continuously from planting, diseases such as cane spot (Elsinoe veneta), spur blight (Didymella applanata), cane blight (Leptosphaeria coniothyrium), raspberry yellow rust (Phragmidium rubi-idaei) and powdery mildew (Sphaerotheca macularis [S. humuli]) can become serious threats to production in some cultivars, in addition to the constant risk of grey mould. Cultural methods that reduce the risk of fungal diseases and optimize the benefit offered by restricted fungicide application will be discussed within the context of integrated pest management.