I am going to move my history and recollection articles into the herbicide era for a while. Good herbicides rather quickly displaced most of the things I have written about to this point.
When I began my career as a weed scientist in 1974, we had propanil (Stam), Ordram and the phenoxy herbicides in rice, which would seem like a very limited arsenal now. However, we got along quite well with them at the time. A typical program was Stam it, Stam it and, if needed, Ordram it for grass control and apply a mixture of 2,4-D and 2,4,5-T at midseason for broadleaf and aquatic weed control.
In cotton, a grower would typically apply Treflan or another DNA herbicide before planting, Cotoran or Karmex behind the press wheel. With these you hoped to get the cotton out of the ground with an established height differential so postemergence directed sprays could be effective. The first post-directed spray would be something relatively mild, like Cotoran plus MSMA under 2 to 3-inch cotton (as best you could get it under there). As the cotton grew, hotter herbicides could be used.
We got along with the program okay — it was the best we had. However, if the DNA herbicides were incorporated too deeply, they could prune the cotton roots. If the rate of the pre-emergence treatment was pushed a little too high and the weather turned cold and wet, crop injury occurred — sometimes to the point of replanting.
Even when the cotton survived, stunting often prevented a height difference between the crop and weeds. This often required the farmer to go over-the-top with Cotoran or DSMA or both as a salvage treatment in an attempt to establish the height difference. There was a true art to cotton weed control in that system, and some growers could consistently pull it off better than others.
For a long time I dreaded cotton weed control talks because there was nothing new to talk about.
In a Roundup Ready system in cotton now, we are essentially going back to the weed control program of the 1970s and 1980s, using the same residual herbicides and directing pretty much the same herbicides with hoods. That is not all bad, but sometimes bad things like crop injury can happen and the system will require much more price timing and the “art factor” will come back into the picture.
Soybean weed control was actually even more difficult in my early career than cotton weed control. We had Treflan, Lasso and perhaps some others, and they were excellent herbicides. However, these were primarily grass and smooth or redroot pigweed herbicides. By the time I began my career they had been so effective that species shifts were occurring and we were a cocklebur and morningglory state. In fact the charge I was given the first day on the job by my boss was “get the cockleburs out of the soybeans on Hwy. 67.” I never understood the significance of Hwy. 67, but I did not ask.
The system of the day was to get the grasses and pigweed out with Treflan or a competing herbicide, apply a soybean cracking stage treatment of dinitro or Dyanap in an attempt to establish a height difference between the soybeans and weeds to post direct spray some more dinitro or, later, 2,4-DB. That was a very frustrating system, but a lot of growers made it work.
Failure to get the height difference resulted in growers spraying dinitro, Dyanap or 2,4-DB over the top, hoping they injured the weeds more than the soybeans. While we are going backward in our weed control programs, I am confident we will not go back to dinitro and dinitro-containing compounds. They were highly toxic and when EPA canned them one actually had to agree. Those were bad news to use.
My point through all of this is how far backward are we going to let this thing go? We are already back to chopping in a lot of fields. Every advancement or attempted advancement I have discussed was for the purpose of eliminating hand labor.