Oak Decline Fungal Mat

This fungus generally forms in spring.

Oak decline fungal mat. Oak wilt is a vascular wilt disease of oak trees caused by the fungus ceratocystis fagacearum. Occurs on species in both the red oak and white oak groups. Oak wilt is a disease which produces a fungus that essentially clogs the water conducting vessels of an oak. Infected oak trees contain fungal mats that form under bark particularly in diseased red oak trees.

On the mat are spores responsible for the fungus that produces and spreads oak wilt. The fungus causes leaf cells to divide abnormally and enlarge. Recent evidence suggests that oak wilt is an exotic disease that arrived in north america in the early 1900s. White oak group bottom image.

It does not form on live oaks these fungal mats produce a fruity odor that attracts various insects particularly sap feeding nitidulid beetles. Fungal mats expand in such a way underneath the bark that they cause the exposed outer bark of the affected oak to split open. Leaves have rounded lobes when present and lack a bristle at the tips of both leaves and lobes. Fungal mats are reliable indicators for diagnosis of oak wilt.

Post oak bur oak chestnut oak chinkapin oak swamp chestnut oak overcup oak and live oak. Armillaria root rot this fungal disease infects and kills cambial tissue causing the. Let s examine ways in which to differentiate oak wilt and oak decline. Isolating and identifying the fungus delayed recognition of the extent of its impact until the 1980s.

The mats also produce a fermented fruity aroma that attracts vectors primarily small sap feeding beetles known as nitidulid. The fungus is destroyed by heat and will not even survive in dry firewood. Without the fluidity of this vital element necessary for its survival an oak will succumb to wilting hence the disease s namesake and eventually death. The fungus enters the tree and stops the flow of water as well as elements by plugging the vessels in the vascular system.

In texas these specialized spore producing structures most often form in the spring on red oaks that developed advanced symptoms of oak wilt the previous late summer or fall. Only wood that has been cured for an entire summer should be stored in the vicinity of uninfected red or live oaks. And only on infected red oaks in a particular stage of decline. Underground through the root grafts or above ground through the spread of nitidulid beetles also known as sap beetles carry spores of the fungus from spore mats on infected trees to wounds on healthy trees causing infection and death of the tree.

However the fungus has never been reported by any country other than the united states so its origin remains unknown. Oak wilt can spread through the fungus or roots. If you utilize red oak firewood try to purchase wood from trees that have not been infected or killed from oak wilt. Fungal mats are viable that is producing spores for a.

If you flip the leaf over you will observe light green cup like depressions.