Hello I was wondering if anyone has run into much of this with killing younger trees. I went today to look at three Colorado Blue Spruce and it appears to be what is effecting them. One of them is almost completely dead while the other two look like they can be salvaged. Everything I have read discussed using Chlorothalonil as a foliar spray. I was wondering if there was any type of basal drench that works for this too. Any information would be appreciated.
Rizospheara needlecast on Spruce
- Thread starter PUClimber
- Start date
rfwoodvt
New member
- Location
- This side of eternity.
Hey PUC,
I've had the same question in my mind for a while now.
Bottom line is that, so far, the only registered products for rhizosphaera needle cast are all contact fungicides. Chlorothalonil being the most prevalent.
Each year I deal with a bunch of "day late, dollar short" requests to help save Picea pungens that have suffered rhizosppaera for too many years. many of these are dead or ought to be dead. pruning the deadwood would help but all that would be left would be a pom-pom tree about 30 feet high.
Would be nice to come up with something that helps that you don't have to spray.
For flowering crabs (applescab) and anthracnose prone trees it appears that direct inject nutrients containing phosphite have antifungal qualities but I haven't heard of it being effective in spruce.
Since those supplements are not considered a registered fungicide it might be worth experimenting on spruces by boosting the trees own defenses with a nutrient injection if the customer is willing.
Just be sure they understand you are only supplementing nutrients to allow the tree to better use it's own defenses and that you are not using it as a fungicide. To do otherwise you would be running afoul of FIFRA regulations.
Phosphite injectable is also available labeled as a fungicide but I don't know if it is labeled for spruce. It is definitely not labeled for needlecast.
I've had the same question in my mind for a while now.
Bottom line is that, so far, the only registered products for rhizosphaera needle cast are all contact fungicides. Chlorothalonil being the most prevalent.
Each year I deal with a bunch of "day late, dollar short" requests to help save Picea pungens that have suffered rhizosppaera for too many years. many of these are dead or ought to be dead. pruning the deadwood would help but all that would be left would be a pom-pom tree about 30 feet high.
Would be nice to come up with something that helps that you don't have to spray.
For flowering crabs (applescab) and anthracnose prone trees it appears that direct inject nutrients containing phosphite have antifungal qualities but I haven't heard of it being effective in spruce.
Since those supplements are not considered a registered fungicide it might be worth experimenting on spruces by boosting the trees own defenses with a nutrient injection if the customer is willing.
Just be sure they understand you are only supplementing nutrients to allow the tree to better use it's own defenses and that you are not using it as a fungicide. To do otherwise you would be running afoul of FIFRA regulations.
Phosphite injectable is also available labeled as a fungicide but I don't know if it is labeled for spruce. It is definitely not labeled for needlecast.
- Location
- Sioux Falls, SD
Living on the prairie, and in the Red River valley, I run into needlecast every year. As a matter of fact I already have 4-5 separate jobs lined up for this spring... Also, living in farm country, I have no problem getting my hand on Chlorothalonil. I have found that Bravo with Weatherstick has worked the best. Its primarily labeled for and widely used around here for beans.
I have not come across or heard of any soil injections or systemic fungicides for the fungus.
As for the fungus and younger trees, I have seen it on P. pungens around here as small as 15 inches tall...
I generally have gone by the guideline that if more than 50% of the branch whorls are effected, the tree is beyond treatment. Although, that is to say my guidelines vary between species and soil and growing conditions. For example a 20' blue spruce with about 50% infection all by its self in a open yard that otherwise looks healthy and vigorous, I will treat. On the other hand the same sized tree in a tight row planting, I may not treat. This is because without the proper ventilation the problem with only return in a few years. Of course these are my recommendations...
Hope that helps...
I have not come across or heard of any soil injections or systemic fungicides for the fungus.
As for the fungus and younger trees, I have seen it on P. pungens around here as small as 15 inches tall...
I generally have gone by the guideline that if more than 50% of the branch whorls are effected, the tree is beyond treatment. Although, that is to say my guidelines vary between species and soil and growing conditions. For example a 20' blue spruce with about 50% infection all by its self in a open yard that otherwise looks healthy and vigorous, I will treat. On the other hand the same sized tree in a tight row planting, I may not treat. This is because without the proper ventilation the problem with only return in a few years. Of course these are my recommendations...
Hope that helps...
