Effect of periodical cicada injury and degree of fire blight severity on Asian pear cultivars

Sixteen Asian pear cultivars grown at Virginia Gold Orchard near Natural Bridge, VA were evaluated for shoot damage from the seventeen-year cicada (Magicicada septemdecim L.), followed by fire blight infection by the bacterium Erwinia amylovora [(Burr.)Winsl. et al.]. The Japanese pear cultivars, 'Yoi nashi' and 'Ichiban nashi,' proved to be the most susceptible; whereas two Korean types, 'Ar-rirang 1' and 'Korean Giant,' were most resistant. Two Japanese cultivars, 'Shinko' and 'Singo,' proved to have intermediate resistance. All cultivars exhibited some degree of cicada damage and 68% showed a strong correlation between cicada injury and fire blight severity. Those with the softest woody branches were attacked and injured most severely.