Red Pine Pocket Mortality

Red Pine Pocket Mortality - Management

The biology of RPPM is not fully understood, and at this point, there is no specific control that is proven to be effective to limit the further spread of this problem.

Compare the Pests

Annosum Root Rot and Red Pine Pocket Mortality share many characteristics. Learn how they are different.

Management

Annosum root rot

Red Pine Pocket Mortality

During thinnings, harvesting trees that are showing dieback (fader trees) along the margin of the pocket will help reduce economic losses. Harvesting additional healthy trees along the pocket margin and into the healthy stand will delay the appearance of crown symptoms in the stand. However, it is likely that the dieback and mortality of additional trees will eventually occur. When salvage harvesting is considered, foresters and landowners should choose a practice that would best suit their long-term forest management plan and management objectives. Management options are listed below. Some of the options presented here include practices that have been performed on an experimental basis in a hope of reducing the risk of further spread of the problem, however the effectiveness of these approaches is unknown.

Harvesting Options

a) Leave the pocket as a natural opening.

b) Cut dead trees and trees that are showing dieback and/or yellowing of the foliage (fader trees) within and adjacent to the pocket.

c) Cut dead trees and trees that are showing dieback and/or yellowing of the foliage (fader trees), and also cut a buffer area around the pocket.

d) Cut dead trees and trees that are showing dieback and/or yellowing of the foliage (fader trees), cut a buffer area around the pocket, and create root graft barriers around the buffer area by severing the root system.

e) Cut dead trees and trees that are showing dieback and/or yellowing of the foliage (fader trees), cut a buffer area around the pocket as described above, and treat the stumps with a herbicide, such as Garlon 4 (Triclopyr), Tahoe 4E (Triclopyr)¹ or other products that are labeled for cut surface applications.

Other Options

Although rarely practical, removing freshly cut stumps will reduce feeding sites for the root collar weevil and the red turpentine beetle. These beetles are considered to be vectors that transmit the root disease.

Relationship to Thinning

Red pine pockets are more common in thinned stands than in unthinned stands. The increased activity of the insects known to vector Leptographium spp. and/or the change in microclimate following a thinning, are likely related to the initiation of this syndrome in thinned stands.

Thinning is a necessary management tool used to maintain healthy and vigorous red pine plantations. Overstocked or very dense stands of red pine are more susceptible to attack by bark beetles. Thus, continue to thin red pine plantations as planned by a professional forester.

Relationship to Mixed Plantings

RPPM has only been observed affecting red pine. Observations of stands where rows of white pine were mixed with rows of red pine have shown that pocket mortality is limited to red pine, even when growing in close proximity to white pine and other tree species. Consult with a professional forester regarding your options for mixed plantings.

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