By Brian Hefty

  1. Yellow – Sonalan, Treflan, or Prowl – $4 – $13
  2. PPO – Valor or Authority – $7 – $9 after rebate
  3. Metribuzin (the old Sencor or Lexone) – $2 – $4

If you use a combination of these three products this year pre-plant in your soybeans, your odds of having 99% control on most Roundup-resistant weeds is very high.  This three-way combo is excellent on Palmer pigweed, waterhemp, redroot pigweed, lambsquarters, kochia, common ragweed, giant ragweed and almost every annual grass.

No-till/strip-till: Every single one of these products can fit in your situation except Sonalan or Treflan.  Valor, Authority and metribuzin all have great burndown activity AND excellent residual, depending on the rate you use.

Authority: You can’t buy Authority all by itself; it comes only in premixes, and the one we recommend most is Authority MTZ, which combines the Authority AND the metribuzin all in one.

High soil pH (over 7.4): All these products work fine with little to no crop injury risk except metribuzin in high pH soils.  All you need to do is cut the rate of metribuzin, and you’ll be fine.  Metribuzin is just more active in high pH soils, so you can use less, spend less and still get the same weed-killing power.

Sandy soil:  Same thing as the high pH ground – just cut the metribuzin rate.

Cost: What does a weedy field cost you in lost yield?  What does it cost to “try” to kill your weeds post-emerge when Roundup doesn’t work?  Isn’t it worth an investment of the equivalent of 1 to 1.5 bushels of soybeans to potentially gain several bushels from improved weed control?  Plus, you’ll sleep a lot easier knowing you don’t have to worry about Roundup-resistant weeds because you have the best possible pre-emerge herbicide program in your fields.

Flexstar, FirstRate and Pursuit: We love all three of these products – post-emerge, not pre.  Save these three active ingredients for post, just in case, because you shouldn’t use any of them twice per season due to plant-back restrictions.  Use the yellow, PPO and metribuzin combo for the best results on the weeds listed above.