At Green Shoots, we sell concentrated weed killer and our foam herbicide dispenser systems help you
apply that weed killer precisely and with low drift. Concentrated weed killer or herbicide is not just more economical. It is also more effective.
Read this paper (link) from Bryan Young, currently a professor at Purdue about glyphosate rates. In it he says: “The most consistent application factor that can increase glyphosate efficacy is lower carrier volumes.” What does Professor Young mean by this? He means that by adding less carrier (i.e., water) and increasing the amount of glyphosate herbicide (i.e., increasing the herbicide concentration) in the spray solution, the herbicide is more effective. Moreover, this is the case even though an application may cover less of the target plant.
Take a look at the photos below and this video to see before and after images of weeds treated with low volume/high concentration applications: Video (link). As you will see in the foliar applications, very small amounts of herbicide are applied to very small areas of foliage (probably covering less than 10% of the green foliage). In spite of the small amount of coverage, the weeds were completely killed.