Pear: Crown gall categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Large gall on crownPhoto by: R.S. Byther Biology Crown gall is caused by a soilborne bacterium. The bacteria infect through wounds on the crown and roots. Young galls are fleshy, white, enlarged masses on the roots or stems. Older galls are hardened […]
Pear: European canker (Nectria canker) categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Mature European canker on branchPhoto by: R.S. Byther Biology Nectria or European canker is a fungal disease affecting the twigs and branches of pear and apple. Young cankers occur at leaf nodes on twigs and are sunken, dark, and water-soaked […]
Pear: Fire blight categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Fire blight infected leavesPhoto by: G.G. Grove Biology Fire blight is a bacterial infection which typically attacks via wounds or blossoms. Initially, twigs and flowers appear water-soaked. Infected tissues quickly turn brown to black and die back, often bending over in a […]
Pear: Pacific Coast pear rust categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Pear rust infection on leaf petiolePhoto by: R.S. Byther Biology Pacific Coast pear rust is a fungal disease affecting pears, hawthorn, apple, crabapple, serviceberry, quince, and mountain ash. The alternate host is the incense cedar (Calocedrus decurrens), which develops witches’ […]
Pear: Pear trellis rust categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Upper and lower leaf surface on Pyrus sp.Photo by: F. Geller-Grimm, commons.wikimedia.org Biology Pear trellis rust is a fungal disease that attacks pear trees and junipers. It is commonly reported on pear leaves in western Washington. Like many rust diseases, pear […]
Pear: Powdery mildew categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Powdery mildew on apple leavesPhoto by: R.S. Byther Biology Powdery mildew is a fungal disease found on twigs, leaves, blossoms, and fruit. New growth is particularly susceptible. The entire terminal may become covered with powdery mildew. Leaves develop a characteristic gray-white powdery […]
Pear: Pseudomonas blossom blast and dieback categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Pseudomonas cankers on pear twigsPhoto by: R.S. Byther Biology Blossom blast and dieback is caused by a bacterial infection. The infection causes buds to turn a papery brown and die. Leaves may be spotted. Flower petals and stems may […]
Pear: Scab categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Scab symptoms on pear fruitPhoto by: R.S. Byther Biology Scab on pear is a fungal disease very similar to apple scab. The disease infects during wet weather in the spring and summer. Lesions appear on leaves, petioles, twigs, and fruit. The spots enlarge […]
Pear: Stony pit categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Pear stony pit virus symptoms on fruitPhoto by: R.S. Byther Biology Stony pit is a virus disease of pears apparently spread by vegetative propagation (budding, grafting, rooting cuttings). Insects are not known to carry the virus. The disease primarily affects the fruit. […]
Pear: Virus diseases categories: Pear Pear Diseases Tree Fruits revision date: 2022-12-05 12:00 Apple mosaic virus foliar symptomsPhoto by: R.S. Byther Biology Virus diseases of pears in home orchards seldom cause significant problems. Symptoms of common viruses are seen on bark, leaves, and fruit. Some virus diseases may cause bark to appear roughened or blistered. […]