We seem to be on the tail end of a very difficult burndown season. Following all the field work we accomplished and a very dry fall last year, I felt spring burndown would not be a major problem this year. Wow, was I ever wrong!

It is easy to blame some of the lack of performance on environmental conditions, but environmental conditions were no worse and arguably better than average.

I do think we have gotten somewhat lax in our commitment to good application techniques. If we consider that none of our burndown herbicides including glyphosate, dicamba, 2,4-D, Firstshot and Valor are really great henbit products, it stands to reason that good coverage is essential for satisfactory control.

There has been a lot of discussion about lack of coverage with air induction spray tips and judging from the excessive amount of glyphosate drift on wheat this year, we must have switched everything to mist blowers. There have been tremendous improvements in spray technology over the past few years and the AI tips we used earlier may not be the ones on the market today.

I don’t get too excited about whether or not a tip is considered AI. I like to use a tip that can provide the desired volume with a uniform, medium-sized droplet with few very small or very large droplets with a moderate pressure and speed.

It is difficult to achieve this with a ground rig moving 18 to 20 mph applying 6 gpa with 100 psi or an airplane flying 135 mph applying 2 to 3 gpa in an 8 to 10 mph crosswind.

Arkansas State regulations on aerial applications read: “The spray boom height at the time of product release shall not exceed 15 feet above the crop canopy. Where obstructions in or adjacent to the field of application will not safely allow application at the 15 foot level, a higher elevation may be used in the vicinity of such obstructions.”

If I were traveling 135 mph 15 feet above the top of henbit, the ground would be a major obstruction and I suspect this is why most burndown herbicides are released at a much higher level. It only takes a wind puff, not a wind current, to distort a 3 gpa spray pattern released 50 feet above the canopy. This results in incomplete coverage or one side of the bed being burned and the other looking like it hasn’t been sprayed. Does this sound familiar?

But, you say, dicamba and glyphosate are some of the most readily absorbed and translocated herbicides we use and should not require the same attention to coverage as paraquat. This is true, but remember we are using herbicides that have only moderate efficacy on this weed when everything is correct.

Discussions about burndown applications always get around to what additives should be in the tank. This opens a whole new can of worms and for sure all surfactants are not created equal. I have always contended that if a herbicide required special surfactants, the manufacturer should add them to the formulation prior to putting it in the bottle.

Most herbicides are not good enough to justify having to jump through a bunch of hoops in order to make them work. This just leads to inconsistency and disappointment to everyone.