Upcoming Weed Management Action
The following is a public notice from the Central New Mexico Cooperative Weed Management Area:
The week of September 21 -25, 2009, the Central New Mexico Cooperative Weed Management Area in conjunction with the New Mexico State Land Office and our Cooperators are going to aerially spray Russian knapweed on New Mexico Highway 41 one-half mile north of the intersection of NM Highways 41 and 542. Treatment of Russian knapweed is planned for the west side of NM State Highway 41 just to the west of the highway right-a-way. Acres planned for treatment include approximately 160 acres of State and Private Lands.
Noxious weed species have significantly degraded New Mexico land¬scapes. Many types of grassland in New Mexico are dominated by Russian Knapweed and other non-native and invasive plants that established themselves when land is disturbed. These ecosystems support much lower numbers of wildlife and livestock, and harm watersheds by exhibiting higher runoff (and flash flooding) during rain events, resulting in much lower soil moisture and groundwater.
The Central New Mexico Cooperative Weed Management Area and New Mexico State Land Office are planning to treat the invasive Russian knapweed. The herbicide proposed for treatment of Russian knapweed on the pasture land is Milestone (aminopyralid) at a rate of 7 oz. per acre. The herbicide proposed for treatment of Russian knapweed on the irrigated land is GrazonNext (aminopryalid plus 2,4-D) at a rate of 2 ½ pints per acre. The herbicide would be added to a “tank mix” of water, a nonionic surfactant, and drift control, which is aerially applied at a rate of five gallons per acre from a fixed wing aircraft.
Use of the Milestone and GrazonNext should occur during the fall when soil temperatures cool sufficiently and the Russian knapweed is in the dormant stage. The herbicide is absorbed directly through the leaf surface and roots, and becomes active in the plant.
In arid climates, the half-life of the herbicide is expected to be up to 90 days. This suggests that forbs and shrubs could begin to re-establish early in the growing season of the following year from the soil seed bank, depending on the amount and timing of precipitation received.
Because the herbicide is selective for broadleaf shrubs and forbs, grasses would benefit from the reduction of competition for nutrients and space, and should increase in cover and density significantly. Adequate grazing rest following the treatment should promote grass recovery.
There are no elevated health or water quality issues related to this action.
For more information please contact Cheri Lujan, District Manager of the East Torrance Soil and Water Conservation District at 505-384-2272, Ext. 3 and/or Tom Perkins, District Resource Manager for the New Mexico State Land Office at 505-832-6213 or 575-799-5162.