Green Industry - A Knowledge Portal for Commercial Horticulture in Wisconsin (sponsored by University of Wisconsin-Extension)
Diagnostics - Problem Details
Root rot (woody plants) - Phytophthora species (W)
Damage
Gardeners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggestareardenersadners often become aware of root rot problems when they see above ground symptoms of the disease. Plants with root rot are often stunted or wilted, and may have leaves with a yellow or red color, suggesting a nutrient deficiency. Examination of the roots of these plants reveals tissue that is soft and brown.
Remarks
May be very difficult to control. Sanitation is important to prevent the spread of the disease.
Chemical Controls
- Boscalid+Pyraclostrobin
- Signal Word: Caution
Pesticide Class: Local Protectant - Cyazofamid
- Signal Word: Caution
Pesticide Class: Protectant - Dimethomorph
- Signal Word: Caution
Pesticide Class: Local systemic - Etridiazole
- Signal Word: Warning
Pesticide Class: Protectant - Etridiazole+Thiophanate-methyl
- Signal Word: Danger
Pesticide Class: Protectant, Systemic-upward only - Fenamidone
- Signal Word: Warning
Pesticide Class: Protectant - Fludioxonil+Mefenoxam
- Signal Word: Caution
Pesticide Class: Protectant, Systemic-upward only - Fosetyl-aluminum
- Signal Word: Caution
Pesticide Class: Systemic - Mefenoxam
- Signal Word: Warning
Pesticide Class: Systemic-upward only - Phosphorous acid
- Signal Word: Caution
Pesticide Class: Systemic - Propamocarb-hydrochloride
- Signal Word: Caution
Pesticide Class: Systemic-upward only - Pyraclostrobin
- Signal Word: Caution
Pesticide Class: Local protectant - Trifloxystrobin
- Signal Word: Caution
Pesticide Class: Local protectant
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
Young apple tree root system infected with Phytophthora root and collar rot.
Symptoms of Phytophthora infection, early fall coloration, on apple.
Browning of needles, needle death and needlecast on Fraser fir caused by Phytophthora.
Fraser fir killed by Phytophthora.
Apple fruit showing symptoms after being infected with Phytophthora.
Common alder showing signs of infection with Phytophthora root and collar rot: tarry spots on bark.
Alder species infected with Phytophthora showing tarry spots on outer bark and orange-brown necrosis of inner bark.