By Brian Hefty

Weeds are still one of the biggest yield-robbers in fields today, often taking 10% or more of your family’s income!

Over the years, it seems like the emphasis we used to have on weed control has faded.  I find many farmers I talk to now willing to accept a few weeds in their fields.  I am also shocked at how many people will let weeds emerge before making their first pass of herbicide in the field.  Small weeds can hurt yield, too, so early applications, especially pre-emerge, are a big key to maximizing yield.  Look at almost any weed trial ever done, and you will see that great pre-emerge weed control leads to top yields.

Personally, I go back to Pursuit to put the blame on how and when things started to go wrong.  Before Pursuit, there were no good post-emerge soybean options, so everyone used pre-emerge herbicides.  Do you remember those days?  Why do you think we had far fewer issues back then with waterhemp, Palmer pigweed, marestail, common or giant ragweed, lambsquarters, or kochia?  It’s because everyone was using pre’s!

Yes, I do recommend planting Xtend or Enlist so you have more herbicide options post-emerge, but let’s get back to basics.  Outstanding weed control starts with pre-emerge herbicides.  In soybeans, we strongly recommend using 3 EFFECTIVE modes of action on your target weeds before those weeds ever come out of the ground.

Here are the ones we usually talk about.

Yellow – this means either Trifluralin in conventional-till or Prowl in no-till. Trifluralin is around $4, so if you are doing any tillage at all in the spring, save yourself some money.  Apply Trifluralin and incorporate.  Otherwise, use Prowl.

Metribuzin – yes, you can use this active ingredient even in high pH soils. In high pH, you get to save money by cutting the rate down to around a $2 per acre level, but you will still get great control.  In soil pH under 7.5, your cost will likely be $4 to $5 per acre.  While the yellows have little to no burndown activity, metribuzin has quite a bit.

PPO – here, we recommend either Valor or Authority. Thanks to rebates, you may pay as little as $2 per acre up to $6 per acre for a standard rate.  These products are the backbone to the 3 Pre program we talk about so often.  They offer great residual, good burndown, and activity on almost every Roundup-resistant broadleaf weed.

About the only addition we will make to this is FirstRate (think AuthorityFirst or Sonic) for an extra kicker on ragweed, although I certainly understand if you have to apply post-plant, pre-emerge, and you want to switch the yellow out for a Group 15 (Warrant, Dual, Zidua, etc.).  I would rather have you save the Group 15 for early post, but that’s your call.

Regardless of your trait package, you need great pre-emerge weed control.  Here are two ways you can justify this economically.

It doesn’t cost much, and weeds cost a lot more, whether you control them later on or not. Add up the dollars I gave you above.  You can run appropriate rates of all of them in the range of $8 to $20, depending on which products you pick and rates you use for metribuzin, based on soil type.  A yield loss of about 4 bushels per acre is what we’ve seen over the years when a pre-emerge herbicide isn’t used.  If you let weeds emerge, they rob yield.    Plus, when you use the 3 Pre program, you will likely get 99% control of almost all Roundup-resistant weeds for months.  The 3 Pre program has never cost as little as it does this year thanks to price reductions and rebates, so it is now affordable for everyone.

By using the 3 Pre program instead of just one or two modes of action pre-emerge, you can often save a post-emerge trip. It costs money to apply an extra shot of Roundup plus dicamba or 2,4-D, and just think if you have to use a full rate of Cadet or Cobra later on.  By getting great pre-emerge control, you’ll sleep easier, because you won’t have to rush to the field with an extra, early application, and even when you do spray later on, you’ll have so many less weeds that achieving 100% control with your post spray will be much easier.