Despite the long history of this disease on grapevines, published research on disease progression in vineyards and control treatments for grapevines is scant. The purpose of our research is to gain an understanding of how oak root fungus infects grapevines and spreads within vineyards with the ultimate goal of developing a reliable management plan for control of Armillaria root disease. Armillaria mellea does not enter vineyards by wind-blown spores.
Inoculum is present belowground in the form of infected roots.
Removing all roots from the soil would likely ensure permanent control of root disease, but this is a difficult, and unrealistic, task. Unless fumigant reaches all underground inoculum, permanent control will not be achieved. Based on the lack of effective chemical controls and the frequency of A. mellea on the roots of native hosts, resistant rootstocks may provide long-term control of Armillaria root disease in vineyards. We have two screening experiments in progress that include 20 different rootstocks. Rootstocks that experience less mortality, such as 110R and Freedom, tend to exhibit defense responses, such as formation of callus tissue, or escape infection altogether more frequently than rootstocks that experience more mortality, such as Riparia Gloire or O39-16.