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Root rot (woody plants) - Rhizoctonia species (W)

Damage

Symptoms on the above ground parts of larger plants include necrotic spots and blotches on the leaves, shoot blight and dieback.

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

Signal Word: Caution
Pesticide Class: Local protectant

Iprodione+Thiophanate-methyl

Signal Word: Caution
Pesticide Class: Local Protectant, Systemic-upward only

PCNB

Signal Word: Caution
Pesticide Class: Protectant

Polyoxin-D Zinc Salt

Signal Word: Caution
Pesticide Class: Local protectant

Pyraclostrobin

Signal Word: Caution
Pesticide Class: Local 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

leaves, roots, trunk

Plant Environment

greenhouse, outdoors

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

• Acer - Maple
• Aesculus - Buckeye
• Amelanchier - Serviceberry
• Clematis - Clematis
• Cotoneaster - Cotoneaster

Photos

Rose species showing signs of infection (light-colored corky areas) on stems.

Another view of rose species showing signs of infection (light-colored corky areas) on stems.