Weeds will always become resistant to herbicides. We can mitigate that and slow down the process but I don't think we will ever eliminate it. Most organism populations have a fairly wide genetic distribution curve. There is purpose behind this. Skinny folks may out run predators more often than their fat colleagues but don't survive famine as well. Genetic variability protects the species.
When we develop herbicides, we target the general population of weeds. Even when the herbicide targets a small group of weed species, it targets the general genetic population. The result is that when we apply herbicide to weeds, some small part of the population just has the genetic makeup that allow them to survive and reproduce. We have now produced a second generation of weed that has a higher percentage of plants with some resistance to that herbicide. Repeat this for generations and we get a dominant population of weeds resistant to that herbicide.
Best practices include using herbicides as directed by the label, and relying on a broad spectrum of weed control techniques be they chemical, mechanical, or other.
Plants adapt to herbicides just like they adapt to insects or other challenges in their environment.
What is a "weed"? A weed is just a plant that is growing in some location where you don't want it. Farmers suppress weeds only because the want to maximize the yield of a particular cash crop. Seeing weeds in soybeans may or may not be related to herbicide resistance. Herbicides are generally sprayed on soybeans when they are young. Farmers depend on soybeans forming a canopy to limit light getting to the soil limiting later season weeds. Many weather, insect, or disease issues with beans could cause them to canopy late and where deer browse pressure is heavy can prevent canopy altogether in smaller fields.
What is a "weed" to a food plotter? Again, it is a plant growing in some location where you don't want it. I think many food plotters have imported their concept of weeds from farmers. I know I did when I first started. I wanted to see lush monocultures like farm fields. As I've grown and gained more experience and perspective, my entire approach to weeds is changing. Many plants that are weeds to farmers are just as attractive and nutritious quality deer food as the crops we plant for deer. My tolerance for "weeds" has increased greatly.
Many food plotters think in terms of tonnage. The reality is that deer are browsers and only a fraction of their diet will come from the crops we plant. Does it really matter if a deer gets nutrition from browsing my high quality soybeans or high quality native poke berries? Nope. So, what is the purpose of our food plots? I'd say there are two major purposes. One might be attraction for hunting or harvest. The other is to fill short-term gaps in quality food when nature or nearby agriculture is not producing quality deer food.
Don't kid yourself. If you only have a few acres to work with, nothing you are doing to do will have a measureable impact on your local herd. Stick with plots for attraction during hunting season. However for those working on scale, as yourself if tonnage really matters. If your large plots are not wiped out before the food source has run its course, it has done its job. More tonnage simply won't make it into the bellies of deer.
With all that in mind, I'm tolerating "weeds" much more. In fact, I'm starting to think of my food plots quite differently. I'm beginning to consider them as wildlife openings that contain quality food. This food may be a combination of permaculture, planted crops, deer friendly weeds, and weeds that don't contribute to my deer directly, but may be contributing to the overall health of my soil.
I still use herbicides judiciously when they are called for, but my approach is evolving over time.
Thanks,
Jack
