What is in this article?:
- Texas growers now facing reality of resistant weeds
- Late-season scouting
• In the last two years Texas has come into the real world of weed control issues.
• Glyphosate resistant common waterhemp has been identified in southeast and central Texas.
• Glyphosate resistant Palmer amaranth (pigweed) has been identified on the Texas High Plains.
A SINGLE uncontrolled common waterhemp plant (resistant) is surrounded by controlled plant carcasses.
Paul Baumann may have never claimed kinship with John the Baptist, but at times over the past decade he may have felt something “like a voice crying in the wilderness,” as he tried to warn folks that injudicious use of one specific herbicide would result in selecting for weeds resistant to it.
And lo, it has come to pass. Baumann, Texas A&M AgriLife Extension weed specialist in College Station, says in the last two years Texas has come into the real world of weed control issues with two developments. (1) Glyphosate resistant common waterhemp has been identified in southeast and central Texas. And (2) glyphosate resistant Palmer amaranth (pigweed) has been identified on the Texas High Plains, especially in cotton production areas. So far, Palmer amaranth resistance has not shown up in central and southeast Texas to his knowledge
Baumann will present some of his findings, observations and recommended control programs at the 2013 Beltwide Cotton Conferences in San Antonio, Jan. 7 through 10.
He’s been cautioning Texas growers about the potential for resistance for 10 years or more. A slide he used back in 2001 still shows the reasons why resistance is likely to develop. “Not many wanted to hear that back then,” he says.
The common waterhemp issue has been on his radar since 2005, when the first cases of resistance began to show up. “It was pretty quiet for awhile,” he says, “and the drought of 2011 kind of kept it under wraps. But, in 2012, farmers verified resistance and realized it wasn’t just missed application.”
Palmer amaranth resistance (to glyphosate) was identified for the first time in the High Plains in 2011.