Thirty-three Vaccinium corymbosum selections and cultivars were artificially inoculated with spores of Colletotrichum gloeosporioides in the green fruit stage. Fruit was harvested when ripe and incubated under high-humidity conditions for 1 week, before evaluation. A wide range of susceptibility to anthracnose fruit-rot was found, ranging from 8% to 85%. Among the most-resistant cultivars were: `Elliott' (8%), `Murphy' (8.3%), `Stanley' (13%), and `Weymouth' (16.9%). Among the most-susceptible cultivars were: `Bluetta' (85%), `Spartan' (82.7%), `June' (69.9%), and `Northblue' (69.5%). Uninoculated checks had a maximum of 6% infection.
Mark K. Ehlenfeldt, Allan W. Stretch, and Vickie Brewster
Mark K. Ehlenfeldt, Vickie Brewster, and Allan W. Stretch
Potted plants of 53 highbush and half-high blueberry cultivars were screened for resistance to the blighting phase of mummyberry, Monilinia vaccini-corymbosii under controlled nursery conditions over an 18 day infection period. Significant differences were observed in the susceptibility of different cultivars, with `Bluehaven', `Bluegold', and `Blueray' being among the most susceptible, and `Bluejay', `Jersey', and `Duke' being among the most resistant. Differences were also observed in the latent periods and rate of disease progress which may have a bearing on the severity of the secondary fruit infection phase. Preliminary observations suggest that shoot blighting and fruit infection frequencies are not strongly correlated under high inoculum conditions.