The agent, which consists of live spores of the fungus Verticillium dahliae , is injected into the trunk of healthy elms. The fungus triggers a reaction that increases the ability of the tree to resist DED infection. While these and other results look promising, the product must undergo further testing. Dutch Trig can be injected into a tree in less than 10 minutes and is expected to cost substantially less than the current chemical products on the market. The humid weather that has occurred over much of the state this summer is showing how favorable it can be for powdery mildew development.
Powdery mildews are severe on lilac, phlox, roses, and Monarda.
They also occur on many other hosts. Powdery mildews are easily recognized by the dusty, powdery appearance they cause on leaves of their hosts. When severe, powdery mildews can cause deformation of the leaves. Roses and other plants that have green stems may also be infected on that plant part. Powdery mildews will also colonize flowers and buds on rose, causing color breaks on flowers and bud abortion.