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)."

Wednesday, July 28, 2010

Some Scale Control Results

On June 20th I posted about a spray trial I had applied that day with 4 different materials for control of scale. Meghan Baker helped me collect samples from that study on July 27 and I looked at the results.

The following numbers are the percentage of dead scales based on observing at least 100 scales:
Check -- 53% dead
Movento + Liberate -- 69% dead
Lorsban -- 75% dead
Safari --  83% dead
Dimethoate + Asana -- 84% dead.

Remember that these were applied with a backpack mistblower which never does give as good results as with a high pressure sprayer. Hopefully with a bit more forceful coverage you would be getting closer to 95% control with the Dimethoate +Asana.

The Lorsban results were a bit disappointing. I was hoping control would be better. Safari worked well. I've seen situations when it hasn't worked as well, but there has been plenty of rainfall in that area which probably helped it get in the plant better.

I will re-evaluate control in these trees in the fall to see if any clearer differences emerge. I will also apply these same materials to other trees in September to look further at fall scale control as well as twig aphid control the following spring.

Friday, July 23, 2010

Japanese Beetles

I may not be moving about too well these days, but thankfully others are out in the trees seeing what's going on.

Jeff Owen has told me that he is seeing Japanese beetles on the terminals feeding. He's seeing this in several tree fields to a greater extent than most years.

Japanese beetles are just one of a number of terminal feeders. They tend to feed toward the top of the tree and terminal, creating irregular patches, though in this picture which I took years ago, they are feeding on older growth. Their feeding is swallow, but will result in discoloration and sap flowing.

Usually by the time you notice the feeding, they have done as much damage as they are going to do. They aren't anything to worry about. However, if you are seeing the insects in your trees, you can spot treat with any good insecticide. A backpack mistbower or backpack sprayer is sufficient. When using a backpack sprayer, I like a hollow cone nozzle for applying insecticides.

Tuesday, July 13, 2010

Some Interesting Pictures

I'm sitting at the extension office with my leg propped up after knee surgery. Walking in all these tree fields sure tears up your knees! It will be awhile before I can tromp around again, so I thought I would post some pictures I've been working on while laid up.

The first is a picture I took at Ewing Harmon's on June 29th. He had treated his trees for scale, and it looked like he got good control. This photo shows what folks need to look for after treatment. There aren't any nymphs on the new growth. I hope you can see in this picture that the needles on the newest growth are scale free.

Scales have moved onto 2010 growth, so if you look at fields and aren't seeing the scales on new growth, that's a good sign. Also, it's easy to see the fuzz from the male scales back in the canopy now. If there aren't many of those, that shows good control as well.

I had commented in my June 30 post about the spread of scale at Dale Cornett's field in Watauga County. I made a colorized scheme to show the increase in scale at Dale's which I have photographed below.

I think this is interesting for a couple of reasons. First of all, the most heavily infested trees in 2010 are scattered everywhere, they aren't just concentrated where the most heavily infested trees were in 2008 which was on the far end of the field.

Something else that was interesting was that two years ago, Dale had some trees with heavy incidence of pine needle scale, not just elongate hemlock scale. We didn't find any of those this year. That's good, because we don't need any other major scale problems.

To date, Dale has only used Di-Syston for pest control in these trees.

The annual Watauga County Christmas Tree Grower's Association meeting will be July 29. I hope to go out before that meeting and look at scale control in the plots that I treated before that meeting, and will report at the meeting and in this blog what I find..

The last schematic I will post today depicts IPM in Christmas trees. I created this for the National Christmas Tree Meeting in Winston Salem in August. This Christmas Tree IPM Pyramid shows the importance of a good IPM foundation to ultimately be successful with pest control.

And this is what so many tree growers in North Carolina do. They work hard to get good fertility and ground cover management, then scout to determine what pests they do have. Through this process, their pesticide controls have been more successful. In fact, I haven't heard of anyone that is too upset that Thionex will be taken off the market. They don't need such a strong material. They can get excellent control with safer products.

Anyway, hope everyone enjoys these schematics. Feel free to use them however you can.

Thursday, July 1, 2010

Doug's Color Wheel

Doug Hundley was telling me the other day that he was explaining to a newer grower all the different times of year you could control the different Fraser fir pests. It's amazing how much our knowledge of pest control has changed even over the past few years. When treating for one pest, you can target others that you have as well, either by your choice of pesticides or how thoroughly you spray.

He told me that he took the white paper plate he and the grower were beating pests on, and he drew different color circles to represent the times of year you could control different pests. I thought it was a great idea. So I put together this color wheel. I haven't talked to Doug or others yet to see if my circles correspond to theirs, so let's talk about it. Email me your comments. I can change it however folks see fit.