Progress in Developing Red Raspberries for the South

Abstract

Production of red raspberries in the eastern United States generally is restricted to that area north of the Mason-Dixon line. This is primarily because of susceptibility to leaf spot ( Septoriaspp.) and to cane damage resulting from the fluctuating winter temperatures characteristic of the upper and middle South. Among the American types of red raspberries ( Rubus idaeus-R. strigosisselections) there is no known source of adequate resistance to these limiting factors. The United States Department of Agriculture and the Tennessee and North Carolina Agricultural Experiment Stations have been especially prominent in attempting to introduce such resistance, notably from R. kuntzeanus, R. biflorus, and R. parvifolius(1, 3). Since each of these species is diploid chromos. number = 2n =14 they would be expected to combine satisfactorily with the diploid American types. Several varieties have been introduced, but none has become widely grown because of some shortcoming in one or more essential horticultural characteristics.