The Value of Christmas Trees

"...there is no reason why the joy associated with the Christmas evergreen may not be a means of arousing in the minds of children an appreciation of the beauty and usefulness of trees; and keen appreciation of the beauty and usefulness of trees is a long stop toward the will to plant and care for them (Arthur Sowder, US Forest Service, 1949)."

Monday, October 25, 2010

Fall Needle Shed

I'm getting out of my comfort zone talking about fall needle shed. I don't think we have a good explanation as to why it is happening. It is certainly associated with stress and is worse in some years (like this one) and in some fields than others.

Of course some needle shed occurs every fall. Usually it's the 4th or 5th year needles. The problem occurs when it's the 3rd, 2nd or even the current year's needles. That's when tags start coming out of trees!

These photos are ones I took with Jerry Moody on Friday at a high elevation farm in Avery County. The site was above 4,000 feet, and it was very windy -- that means a stressful site. Though these pictures were taken in Avery, I've heard of a lot more problems in Ashe County where it has been drier this summer and fall.

This tree had only a few areas that had discolored needles.

This tree had excessive shed throughout the whole canopy. It was a very heavy density tree, so it was hard to see from the outside, but it will still impact if this tree can be sold this year.

In some instances we've seen trees like this with current year needle drop that were due to root injury. Fertilizer burn can be one cause of root injury, but this particular field had not had any fertilizer applied since the spring. The shoots of this tree appeared to be healthy, as did the buds for next year. Root loss can also be caused by drought. Fraser fir, being a seed-run crop, will have individual trees that are more susceptible to drought than others.

I've had some calls from growers that are concerned that scales are causing this discoloration. At this site, there were no scales. If in doubt, look at the shoots of several trees. Turn the foliage over to look for the presence of scales. Most of the fall needle problems have not been associated with scales.

Advice for the grower? Keep on top of your fertility. By fertilizing according to soil sample results, hopefully you can avoid many of these problems. If the problem develops, take soil samples and plant tissue samples of healthy verses trees with shedding needles. And get your County Extension Agent involved.

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