Walnut: Anthracnose (Blotch) categories: Tree Fruits Walnut Walnut Diseases last review date: 2025-08-23 12:19 Walnut anthracnose infection on leaf Photo by: R.S. Byther Biology Anthracnose or blotch of walnut is caused by a fungus. The disease affects leaves, young twigs, and nuts. Leaves develop irregularly circular reddish-brown to grayish-brown spots up to 3⁄4″ across. Severe […]
Walnut: Blackline categories: Tree Fruits Walnut Walnut Diseases last review date: 2025-08-23 12:21 Walnut with bark cracks and blackline at graft union Photo by: J. W. Pscheidt Biology Blackline is a viral disease of English walnut (Juglans regia). It causes death of water-conducting tissues at the graft union. Initially, infected trees show poor growth, yellowing […]
Walnut: Blight categories: Tree Fruits Walnut Walnut Diseases last review date: 2025-08-23 12:24 Walnut blight symptoms on husks Photo by: R.S. Byther Biology Walnut blight is a bacterial disease affecting leaves, nuts, and other new growth including flowers. Bacteria are spread to new growth in the spring by rainy weather during the bloom season. Leaves […]
Walnut: Thousand cankers disease categories: Tree Fruits Walnut Walnut Diseases last review date: 2025-08-23 12:29 Biology Thousand cankers disease (TCD) of walnut is a fungal disease associated with and spread by walnut twig beetles (WTB). Beetles feed on both healthy and damaged trees but injured or weakened trees are more susceptible to rapid decline. The […]