Pear: Crown gall Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-08-23 06:32 Last edit date: Large gall on crown Photo 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 […]
Pear: European canker (Nectria canker) Categories: Pear Pear Diseases Tree Fruits Last review date: 2026-08-28 01:39 Last edit date: Mature European canker on branch Photo 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 […]
Pear: Fire blight Categories: Pear Pear Diseases Tree Fruits Last review date: 2026-08-28 02:29 Last edit date: Fire blight infected leaves Photo 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 […]
Pear: Pacific Coast pear rust Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-06-29 11:33 Last edit date: Pear rust infection on leaf petiole Photo 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 […]
Pear: Pear trellis rust Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-06-29 11:26 Last edit date: 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. […]
Pear: Powdery mildew Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-09-12 10:26 Last edit date: Powdery mildew on apple leaves Photo 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 […]
Pear: Pseudomonas blossom blast and dieback Categories: Pear Pear Diseases Tree Fruits Last review date: 2026-08-28 01:39 Last edit date: Pseudomonas cankers on pear twigs Photo 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. […]
Pear: Scab Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-08-23 06:47 Last edit date: Scab symptoms on pear fruit Photo 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, […]
Pear: Stony pit Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-08-23 06:49 Last edit date: Pear stony pit virus symptoms on fruit Photo 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 […]
Pear: Virus diseases Categories: Pear Pear Diseases Tree Fruits Last review date: 2025-08-23 06:54 Last edit date: Apple mosaic virus foliar symptoms Photo 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 […]