ABSTRACT
Breeding of Fragaria×ananassa Duch. (strawberry) began in the early 1800s (Scott and Lawrence, 1975) and Rubus breeding (raspberry, blackberry, and hybrid berries) has been going on since the late part of the 19th century (Dale et al., 1989). Despite the relatively long history of breeding with these crops and the many successes in breeding for disease and pest resistance, there remain disease problems for which there are no known sources of resistance in the available germplasm. In other cases, pests and pathogens have evolved to overcome host resistance that breeders have incorporated in new cultivars. Phytophthora root rot (Phytophthora fragariae f.sp. fragariae) (Nickerson and Jamieson, 1995) in strawberry and raspberry bushy dwarf virus (RB strain) in red raspberry (Barbara et al., 1984) are two examples of pathogens overcoming employed resistance genes. Raspberry aphids, Amphorophora idaei in Europe and A. agathonica in North America, have evolved to overcome resistance genes used widely in raspberry breeding programs to control aphid-borne viruses (Daubeny, 1996). Overuse and/or misuse of fungicides and insecticides has resulted in the development of pathogens and pests resistant to chemicals. Some chemicals are withdrawn for use on these minor crops because the costs associated with keeping them on the label are prohibitive or the work to get a chemical registered on these minor crops is not done, again as a result of cost considerations. The Food Quality Protection Act in the United States will result in a review of all pesticides and very likely will result in the loss of many of those used currently for control of insects and pathogens of these crops.
