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)."

Thursday, April 15, 2010

Role of Apollo

Several folks have been talking about treating this spring with Apollo plus Dimethoate. Apollo is a miticide with similar activity to Savey. Those Apollo plus Dimethoate should give good control of twig aphids and spider mites, but only fair control of rust mites. After all Apollo, though an ovicide, has no activity against rust mites, just as Savey doesn't.

The kicker is, there are almost no spider mites anywhere. I've worked  tree fields for several weeks, Bryan Davis has, and several other agents. Fields with spider mites are few and far between. I think I've seen a dozen spider mites eggs total in 3 weeks of scouting.

Rust mites, however, are being found frequently. A few fields have high rust mite numbers. Other just have maybe a mite per shoot. (Remember that the treatment threshold is 80% incidence and at least 8 mites per needle).

The mix of Apollo + Dimethoate will knock rust mites down (due to the Dimethoate), but since it is so early in the season, the mites may rebound. That is why in a situation where rust mites are plentiful now, Envidor is the better choice. It controls both spider mites and rust mites. Envidor plus Dimethoate should give excellent and full season control of twig aphids, rust mites and spider mites.

Scouting will determine which blocks should have the Envidor added, and which don't, as rust mites are not a problem in every farm or even on every block on a farm. Don't assume that just because you used either Asana or Talstar last fall that rust mites are a problem. They aren't. You don't know until you go out and look.

And scouting doesn't have to take a lot of time. When I go out with the county agent or technician, it always takes longer because we're talking about control options, showing the grower different pests and the like. But if I was just going out there to scout, it wouldn't take me long at all.

Envidor is only labeled to be applied once per year (as is Savey and I think Apollo as well). This is to reduce the likelihood of resistance. But chances are, spider mites won't develop and become a problem if you have good ground covers. Even during droughty years, we've seen very few farms with bad spider mites in recent years. Once again, a quick scout through should be able to identify problem sites.

So scout. Then chose what you need based on those scouting results.

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