Green Industry - A Knowledge Portal for Commercial Horticulture in Wisconsin (sponsored by University of Wisconsin-Extension)
Diagnostics - Problem Details
Root rot (woody plants) - Cylindrocladium species
Damage
Root infections are characterized by many dark brown to black lesions often with longitudinal cracks. Severe root disease leads to stunting, wilting, yellowing and death. Stem infections of both conifers and broadleaves arise at the leaf bases and may girdle small stems. Diseased conifer needles turn yellow or red-brown. Dark lesions form in the leaves of broadleaf plants. Leaf blight leads to defoliation.
Remarks
May be very difficult to control. Sanitation is important to prevent the spread of the disease.
Chemical Controls
- Azoxystrobin
- Signal Word: Caution
Pesticide Class: Systemic-Upward only - Boscalid+Pyraclostrobin
- Signal Word: Caution
Pesticide Class: Local Protectant - Chlorothalonil+Thiophanate methyl
- Signal Word: Danger
Pesticide Class: Protectant, Systemic-Upward only - Etridiazole+Thiophanate-methyl
- Signal Word: Danger
Pesticide Class: Protectant, Systemic-upward only - Fludioxonil
- Signal Word: Caution
Pesticide Class: Protectant - Fludioxonil+Mefenoxam
- Signal Word: Caution
Pesticide Class: Protectant, Systemic-upward only - Iprodione+Thiophanate-methyl
- Signal Word: Caution
Pesticide Class: Local Protectant, Systemic-upward only - PCNB
- Signal Word: Caution
Pesticide Class: Protectant - Thiophanate-methyl
- Signal Word: Caution
Pesticide Class: Systemic-upward only - Trifloxystrobin
- Signal Word: Caution
Pesticide Class: Local protectant - Triflumizole
- Signal Word: Caution
Pesticide Class: Systemic-upward only
Locations Affected
Plant Environment
Scouting Season:
January - Early , January - Mid , January - Late , February - Early , February - Mid , February - Late , March - Early , March - Mid , March - Late , April - Early , April - Mid , April - Late , May - Early , May - Mid , May - Late , June - Early , June - Mid , June - Late , July - Early , July - Mid , July - Late , August - Early , August - Mid , August - Late , September - Early , September - Mid , September - Late , October - Early , October - Mid , October - Late , November - Early , November - Mid , November - Late , December - Early , December - Mid , December - Late
Plants Affected
Photos
Black fruiting bodies, microsclerotia, on roots of infected yellow poplar seedlings.
Black fruiting bodies, microsclerotia, on roots of infected black walnut seedlings.
Diseased root showing black fruiting bodies, microsclerotia.
Black walnut seedlings showing symptoms of root rot: chlorosis, wilting and death.