By Darren Hefty

While cuts to N, P, and K are tough for most farmers to make, the micronutrients seem to be one budget item that disappears when commodity prices are low. Why is that? First, too many people aren’t measuring them in soil tests or addressing what levels are really needed. Second, I believe hardly any farmer I talk to knows what individual micros even do. The fact is they can make a big difference if you are short. For example, zinc is critical for water utilization in the plant. Boron is important all through the season to help with nitrogen utilization. I could go on and on, but the point is this – micros only cost about $5 per acre to feed this year’s crop. At today’s commodity prices, this is an easy decision.

1. R1 (first flower) to R2 (full flower) – This timing is especially important to get ahead of the toughest diseases like sclerotinia white mold (SWM) and sudden death syndrome (SDS). Many farmers are using a half rate of fungicide at this timing since the crop is so small. However, if you are after SWM or SDS, we suggest you use a full rate, and we often see big yield gains of five to ten bushels per acre. Late R2 is best for a one-shot, general fungicide application if you aren’t worried about SWM or SDS. We usually expect to gain at least two to three bushels per acre at this timing for general diseases (brown spot, cercospora, frogeye leaf spot, pod & stem blight, powdery mildew, rhizoctonia, anthracnose, target spot, etc.). Even at two bushels, if you only invest $6 per acre with $11 soybeans, you more than triple your money!

2. R3 (first pod) to R4 (full pod) – Early R3 is probably the best timing here in most cases, as that is excellent for a one-shot, general fungicide application, and it’s at least two to three weeks after your first SWM application, so your plants need another shot if you want to prevent white mold. Keep in mind, fungicides don’t move from leaf to leaf, so they only protect the leaves that are there at the timing of application. For all our seed growers, they are required to spray a fungicide at least twice because it not only leads to high yields in our production fields, it means bigger, healthier, better-looking seed in the fall.

3. R5 (beginning seed) to R6 (full seed) – Since the soybean price is so high right now, it’s probably worth the money this year to spray at both timings 1 & 2 as I listed earlier, but should you spray a third time? Unless you are trying to stop white mold or if you are going after a very high yield in very humid weather (in Baltic, SD, by the way, the humidity in August the last two years has averaged 79%!), spraying a third time is less likely to pay than the first two applications. However, $11 soybeans gives you a better chance to make it work. If this August is as humid as the last two, we will spray three times in our soybeans. Keep in mind, even if you use the full rate of a great fungicide for about $10 per acre, even if you only gain three bushels, that’s $33 income ($23 net). That’s a 230% ROI! If soybeans were $7 or $8 like we were assuming last summer, while a three-bushel gain still would have more than doubled your money, it would not have provided anywhere close to as many net dollars per acre.

• Insecticide for soybean aphids and other insects for $2 to $4. With the soybean price high, that means the economic threshold for insects is very low. In other words, it doesn’t take many bugs to justify the treatment, especially if you are already spraying something else.

• A natural product in-furrow or early post like Alpha Complete. Gain 3 to 6 bushels for a cost of $13/acre.

• A post-emerge residual herbicide like Warrant Ultra or Anthem Maxx. Better weed control protects several bushels of yield for a net cost after rebates of less than $10/acre.

• Additional P or K. 70-bushel soybeans remove 51 pounds of phosphate and 84 pounds of K2O potassium.