Biocontrol of Ailanthus altissima : inoculation protocol and risk assessment for Verticillium nonalfalfae (Plectosphaerellaceae: Phyllachorales)

However, previous studies evaluating this potential biocontrol utilised a conidial suspension with a short shelf life as inoculum. Anticipating future expanded use of V. nonalfalfae , we evaluated other inoculum formulations, inoculation protocols and sensitivity of non-target (non- Ailanthus ) plant species within Pennsylvania.

The most effective inoculum formulation, with an extended shelf life, was prepared by mixing water with stored, refrigerated soil containing V. nonalfalfae . Less successful, but positive infections were obtained by simply using infected Ailanthus wood and leaves as inoculum. Monthly inoculation of Ailanthus trees demonstrated that the optimal time for successful inoculations was April to May, but limited infections were achieved during all months, including the winter.