Photos: A,B and D are sequential symptoms of oak wilt. C shows infected annual rings in white oak. E shows a mortality center of oak wilt with the infection zone moving outwards. F shows a fungal mat in red oak. Photos taken by: William Ciesla, D.W. French, B.F. Billings, and the Minnesota Department of Natural Resources.
Arborjet recommends a trunk Micro-infusionTM of ALAMO (Propiconazole 14.3%). The active ingredient in ALAMO is propiconazole, a systemic fungicide that will suppress Ceratocystis fagacearum. Because oak wilt is spread through oak roots and insect carriers, Arborjet recommends that you also treat asymptomatic oaks around the infected trees to stop the spread of this disease. Arborjet recommends to use Micro-infusionTM with the Tree I.V. using the Arborplug Technology with #3 Arborplugs.
Generally, the best seasons for Micro-infusionTM are fall and spring. Uptake occurs when trees are transpiring. The environmental conditions that favor uptake are moderate temperatures, adequate soil moisture, and high humidity. Soil temperature should be above 40 degrees for micro-infusion™. Tree health will influence uptake time. Generally, hot weather or dry soil conditions will result in a reduced rate of uptake. If treating trees in the summer, micro-infuse in the morning for the quickest uptake. A dying tree is a poor candidate for treatment. It is the responsibility of the arborist or tree custodian to assess tree health and its potential for recovery before undertaking treatment.
Tree recovery with ALAMO will be proportional to the severity of the infection at the time of treatment. Trunk injection of propiconazole will kill and suppress Ceratocystis fagacearum and allow the tree to refoliate. Residues will persist in the tree for approximately one year.
Left: A healthy Red Oak (Quercus rubra) tree.
Right: A healthy White Oak (Quercus alba) tree.
From: the UCONN Plant Database.
