Are there any evergreens that don't get needle cast rhizosphaeria?

Asked April 13, 2014, 8:08 PM EDT

I have a Christmas tree farm with bad needle cast rhizosphaeria. I've been spraying Banvel, but it doesn't seem to work. Are there any evergreens that don't get this disease? Any suggestions would be appreciated for I'm getting ready to throw in the towel.

Hanover County Virginia lrk needle cast rhizosphaeria christmas tree farm

3 Responses

Banvel is an herbicide, used in corn and turfgrass primarily, to control weeds. Therefore, it would not have any impact on needle cast disease, which is caused by a fungus. This is information from the Connecticut Agricultural Experiment Station: "Recommended chemicals for this disease are: chlorothalonil, chlorothalonil + fenarimol, and mancozeb. The labels on these products contain information on dosage rates and safety precautions. Applications are made before or when new growth is approximately 1½’’ long and again 3 weeks later. Additional applications may be necessary in years with excessive rainfall."

Also ask your local Cooperative Extension agent about soil drench treatments for needle cast. This fungus originates in the soil below your trees.


Not sure if this went through the first time....

Hi Ron,
Banvel is an herbicide...used in corn and turfgrass primarily...to control weeds. Therefore, it would not have any impact on needle cast disease, which is caused by a fungus. This is information from the Connecticut Ag Experiment Station: "Recommended chemicals for this disease are: chlorothalonil, chlorothalonil + fenarimol, and mancozeb. The labels on these products contain information on dosage rates and safety precautions. Applications are made before or when new growth is approximately 1½’’ long and again 3 weeks later. Additional applications may be necessary in years with excessive rainfall." Also look/ask your local extension agent about soil drench treatments for needlecast...this fungus originates in the soil below your trees.
Good luck.

Good morning, Ron.

I've been asked to respond to your question by the outgoing agent in your county. First, are you sure it's Rhizosphaeria? There's another needlecast disease in the area and has a different management protocol. Distinguishing the 2 diseases requires access to a microscope. Once the disease is confirmed, the control is fairly straightforward; new flushes of growth have to be protected and treatment needs to be repeated at 3-4 week intervals until needle mature. In most years, you're talking 2 sprays. Last year being so wet, it may have required 3 sprays.

I'm in Chesterfield County and would be happy to assist you in managing this problem. If you would like to call and discuss, my number is 804.751.4401.

Mike Likins
Chesterfield Extension