Landscape
And
Nursery
Dialog
Mary Ann Rose
Commercial Landscape
& Nursery Specialist
The Ohio State UniversityApril, 1996
New Herbicide Products
Keywords: herbicides,new products, weed control, landscape, nursery
Roundup PRO. Monsanto's Roundup Herbicide for industrial, turf, and ornamental use is being replaced by Roundup PRO. Roundup PRO, like Roundup, is a 41% solution of the active ingredient, glyphosate, but contains an improved surfactant. The new surfactant in Roundup PRO improves foliar penetration and absorption of the
herbicide. It has been a fairly common practice to use additional surfactant with Roundup to improve its effectiveness; this should no longer be necessary with Roundup PRO. By the same token, where we may have been able to use Roundup a bit fast and lose in the past, the new Roundup PRO will be much 'hotter' and needs to be used with even more respect around desirable plants! Advertised advantages of the new product include superior rainfastness (if that's not a word, I just coined it!) and faster burndown. In addition, the EPA signal word has been downgraded from 'Warning' to the lowest and safest category, 'Caution'.
Scythe. Scythe, from Mycogen corporation, is similar to an older product, Sharpshooter (to be discontinued), but is a much stronger contact herbicide that produces rapid burndown of vegetation. Scythe's labeled uses include ornamental & landscape (spot-treatments, trimming, edging), noncrop, golfcourse (edging), turf (site prep only), and greenhouse. Like Sharpshooter, it can be used in the greenhouse or polyhouse under pots and benches while the crop is in place. It also may be used as a directed spray to the base of woody plants in containers; however, I would proceed with extreme caution using it in this manner, since any green stem or leaf tissue will be zapped! The label suggests that you make a test application before extensive use on nursery container stock. This use will probably be welcomed by growers that wish to clean up winter weeds in the containers of dormant, woody plants.
Scythe is a good contact herbicide in its own right, but what's really interesting is that it can be tank-mixed with Roundup to give both rapid burndown and the effective kill of perennials that is the advantage of translocated chemicals like Roundup. Normally we do not mix contact and systemic chemicals because the rapid burndown of foliage prevents movement of the systemic (translocated) chemical into the plant. However, Scythe is the exception, acting as a synergist that improves penetration of Roundup into the leaf.
Scythe must be used at a fairly high concentration (labeled rates are 5 to 10% by volume). When tank-mixed with Roundup, a 3% solution by volume is recommended. The active ingredient in Scythe is an eye-irritant - so use with caution. The EPA signal word is 'Warning'.
0-0 Herbicide. Regel Chemical Co. offers us a new granular product that is a combination of Ronstar (1%) and Goal (2%). It is labeled for selected woody ornamentals in the landscape and nursery. Both of the chemicals in this product are light-activated, so when using on a mulched bed, apply it the surface, instead of below the mulch. This product is a good choice to rotate into the container weed control program in addition to the other granular products commonly used such as Rout, OH2, Snapshot, Ronstar, and Derby. The product literature claims that 0-0 Herbicide will produce better-quality plants because it does not contain root-inhibitors that are in many other products. It is a fact that the active ingredients in 0-0 Herbicide remain at the surface of the media, and act as contact chemicals that burn off weed seedlings as they emerge; thus the potential for root injury to ornamentals
is low with this product. A research project I have in progress will be my first chance to look at 0-0 Herbicide closely.
