Oak leaf blister is caused by the fungus Taphrina caerulescens.. Leaf blister, an infectious disease of many species of oak \൜⠀儀甀攀爀挀甀猀 猀瀀⸀尩 trees, is caused by the fungus ­Taphrina caerulescens. The fungus Taphrina caerulescens causes oak leaf blister.. SYMPTOMS. Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin. References to commercial products or trade names are made with the understanding that no discrimination is intended and no endorsement by Texas AgriLife Extension Service personnel is implied. (Fig 1) From the underside, the affected areas are sunken or depressed. AgriLife Extension's online Bookstore offers educational information and resources related to our many areas of expertise and programming; from agriculture, horticulture, and natural resources to nutrition, wellness for families and youth, and much more. Sign-up to receive email news and alerts from Purdue Landscape Working Group: Copyright © 2020 | An equal access/equal opportunity university | Integrity Statement | Copyright ComplaintsThis work is supported in part by Extension Implementation Grant 2017-70006-27140/ IND011460G4-1013877 from the USDA National Institute of Food and Agriculture, An equal access/equal opportunity university. Fungicide, such as mancozeb or chlorothalonil, can be used as protectants. Hosts. Abnormal growth of leaf includes bulges, depressions, cupping and twisting. Preventative fungicide should be applied just prior to budbreak and through early leaf development for effective control. Once infection has occurred, chemical treatments are ineffective. But we're still suffering from drought in our area and trees are showing stress. Numerous blisters can coalesce to affect entire leaf. Bulges are usually light green, eventually turning to brown as the leaf ages. Abnormal growth of leaf includes bulges, depressions, cupping and twisting. The information given herein is for educational purposes only. Expanded (older) leaves are not susceptible. Expanded (older) leaves are not susceptible. Oak leaf blister is caused by the fungus Taphrina caerulescens. Click for a hub of Extension resources related to the current COVID-19 situation. Infections occur when leaves are emerging. Oak Leaf Blister. Symptoms & Disease Cycle. (Fig 3.) Numerous blisters can coalesce to affect entire leaf. Although leaf blister is unsightly, it does not present any immediate threat to oak trees. Texas Plant Disease Diagnostic Laboratory. Chemical controls are usually not recommended. The fungus causes the young leaves to develop blister-like bumps on their surfaces, with coloration ranging from light green to brown. Species vary in susceptibility, but the water oak is … Infections have been recorded on over 50 different species of oak belonging to both the white oak and red oak groups. Oak leaf blister, a disease caused by the Taphrina caerulescens fungus, attacks most species of oaks found in Louisiana. Symptoms appear as irregularly-shaped bulging spots that appear randomly on leaves or they are clustered together to cause leaf distortion. Then, during the following spring, it is transferred to budding leaves. A unique education agency, the Texas A&M AgriLife Extension Service teaches Texans wherever they live, extending research-based knowledge to benefit their families and communities. Some insect galls may resemble symptoms of oak leaf blister at first glance. (Fig 2) Upon closer inspection, the insect gall is a solid mass of leaf tissue as opposed to the distorted leaf blister caused by Taphrina.