The cut stems of some clonal species, such as gray dogwood (Cornus racemosa), are quite sensitive to glyphosate but grow as dense stands with lots of small stem close together. The conventional way of treating these cut stems with a spray bottle is very time consuming and quite wasteful of herbicide.
For the past five or six years we have been using a technique that we learned from Dale Karow that really works. It makes use of foam paint pads (2 or 3 inches wide) that you can buy at any hardware store. The pad has a wooden dowel on the end, which is inserted into a hole at the end of a broom stick or plastic tube. The foam pad is loaded up with herbicide from a spray bottle carried in the other hand.
The target clone is cut with a motorized brush cutter equipped with a very sharp saw blade. (The blade is sharpened in the field each time the cutter is gassed up.) One person with a brush cutter can keep two or three (or even four) "treaters" busy. No stooping is needed, and a dozen or so cut stems can be treated without moving. A red dye is added to the herbicide in order to keep track of which stems still need treating.
Yesterday we used this technique at Black Earth Rettenmund Prairie on a large patch of prairie willow that had started to take over the top of the north knoll. Although this is a native species, it had begun to spread rather extensively, and since this is an area with lots of "good" forbs, such as wood lily, seneca snakeroot, false toadflax, butterfly weed, etc. etc., we felt it should be controlled. The goal here was to reduce by about one-half the amount of prairie willow in this area.
Willis ran the brush cutter and Kathie and I followed along with the herbicide. The foam pad technique was ideal for this purpose, as the photo below shows.
One of the great advantages of this technique is that it is very economical of herbicide. If you sprayed each of these cut stems from a spray bottle, it would be very difficult to confine the herbicide to the cut stem itself, but with the foam pad, a simple "touch" to each cut stem takes care of it. With the foam pad, all of the herbicide is confined to the stem.
In summary: this technique makes use of crew of two to four people. One operates the brush cutter and the others follow along with herbicide sticks and quickly touch each cut stem. The red dye, an essential part of the technique, shows which areas are still to be treated. An operator can stand in one place and treat at least a dozen cut stems, often more.
The red water-soluble dye is available from, among others, Crop Production Services.
The foam pad technique is great for a volunteer work group. No stooping, no wasting herbicide, very quick. Strongly recommended!
This comment has been removed by a blog administrator.
ReplyDelete