Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/5/2000
Publication Date: 6/1/2000
Citation: Smith, B.J. 2000. Susceptibility of southern highbush blueberry cultivars to Phytophthora root rot. Phytopathology. 90:S72
Technical Abstract: Phytophthora root rot (Phytophthora cinnamomi Rands) is a serious disease of highbush blueberry (Vaccinium corymbosum L.) which is more susceptible than rabbiteye (RE) blueberry (V. ashei Reade). As acreage of southern highbush (SHB) cultivars (hybrids between highbush and "southern" blueberry species) increases so does the potential importance of this disease in southern blueberry fields. This study was initiated to compare the susceptibility of 7 SHB cultivars, Cooper, Gulfcoast, Magnolia, Marimba, Misty, Pearl River and Reveille, and two RE cultivars, Premier and Tifblue, to P. cinnamomi, and to evaluate the effect of bed height and fungicide treatments on disease severity. After two years, root rot symptoms were evident throughout the field, but there were no differences in disease severity or plant vigor due to bed height or fungicide treatment. There were differences among cultivars. The RE cultivars were most vigorous. They and the SHB cultivar Gulfcoast had less severe root rot symptoms than Marimba, Pearl River, Misty and Cooper. After five years, 90% of Gulfcoast and 75% of Tifblue plants were still alive; however, only 7% of the Misty plants had survived.