"I was invited to Memphis last week to share my dealings with glyphosate-resistant weeds and to see the South’s problem with resistant pigweed firsthand. It was a rewarding trip.
The best thing is I met a lot of good people with strong minds who are aware of this problem. Dr. Stephen Powles from Western Australia University was one of those people. He has talked about this problem since his first battle with resistant ryegrass in Australia and New Zealand in 1983. Some farmers are still afraid to plant annual ryegrass as a cover crop for fear of introducing another resistant weed!
The main point he shared at this Bayer Crop Science sponsored event made good sense to me. Get your resistant weed populations down before tackling resistant weeds with glufosinate ammonium, formerly Liberty and now Ignite herbicide. We have lost too many good chemistries already, as retired Extension weed specialist Ford Baldwin lamented, and many farmers remembered the loss of cyanazine or Bladex in corn. The loss of the wonder herbicide glyphosate was compared to losing penicillin to fight human diseases.
The big question was, how do you get resistant weed populations down? The nasty word “tillage” was brought up and many farmers shuddered. I can’t do that in southwest Ohio. My soils are too fragile and erodible, and I have spent considerable effort and money in trying to save them and build them without tearing them apart again.
So, I thought of my crop rotation, spray schedule, chemical rotation and cover crops. The first thing that popped into my mind was that I always have less weeds with cover crops, especially with radishes. I have set a goal to cover all my fields after harvest this fall and try and keep them covered. I intend to smother out my weed population.
There are always escapes. I will carefully use the existing products to kill my weed escapes and always use a residual with glyphosate- and glufosinate-resistant crops. This is working pretty well for me, but I have to get serious about this. Farmers are going to lose their farms and their career if they don’t get a handle on this — seriously.
One farmer we visited had spent $50 on herbicides alone and the soybeans were taken over by resistant pigweeds. The pigweed family, which includes redroot here, tall waterhemp in Iowa and Palmer amaranth in the South, have male and female plants. You can kill the the male, but pollinated females that escape produce thousands of seeds. The seed bank is huge.
Do you have any idea how big your weed seed bank is? You got a glimpse of it in this crazy growing year called 2010. There isn’t a clean field in Ohio that I have seen. There are always escapes, even in the so-called clean fields. Are they resistant? They probably are and if they aren’t, it takes more broad-spectrum chemical than ever to kill them. They will soon be resistant.
We got a good view of the resistant weeds around the world by focusing on the huge Palmer amaranth problem in the Mid-South’s Delta region. Those weeds are out of control. We have to be careful not to ruin Ignite herbicide trying to save Roundup Ready crops.
What I heard and saw made me happy that I have stayed with non-GMO corn and switched back to non-GMO soybeans for a more total weed control solution. I see where wheat and a cover crop are key in my rotation.
This is going to take a farmer-wide and industry-wide effort to avoid the huge problem the South is experiencing, what I see locally and in the Midwest, and even down under in Australia and New Zealand. We have weeds and we have too many resistant weeds!"
Let me ask you, how far have we come in 3 1/2 years?