By Brian Hefty
With margins squeezed on most farms, VT Double Pro corn hybrids became a popular choice this winter. It’s great that you saved money by not investing in a rootworm trait, but I want to talk to you today about managing those fields to still maximize yields.
The most important thing to understand is there is no good way to rescue a rootworm problem. You can try to put on Lorsban at a high rate early post-emerge, but even with 3 or 4 inches of rain, you can’t expect more than 30% to 50% control.
If you are really worried about rootworms, we suggest using dry Force or Aztec. Yes, the control won’t be 99.9% like the Bt rootworm trait is on non-resistant rootworms, but I would still expect 90% to maybe even 95% control for around $20 per acre. Also, you will control many insect species, in addition to rootworms. These include cutworms, seed corn maggots, seed corn beetles, wireworms, and many more. If you have a white grub problem, no single insecticide will be perfect, but Aztec and Force are solid choices.
If cost is your big concern, Brigade (bifenthrin) is around $3 per acre. It won’t mix in liquid fertilizer or with fungicide, but it’s cheap. For just a few dollars more you can get Capture LFR + VGR. This version of bifenthrin does mix well in liquid fertilizer. Plus, the new VGR component is a biological that helps with moisture stress and enhances phosphorus uptake.
If you want to take it a step further, you can get Temitry LFR or Manticor, which are both premixes of Capture LFR and Headline. Temitry LFR and Manticor do mix in liquid fertilizer, so you can get fungicide, insecticide, and fertilizer all in one delivery system.
Just because rootworm pressure was low the last couple of years, that doesn’t mean it will be low again this year. I know you want and need to save money where you can, but you also need to maximize yield, and if you have even a tiny amount of rootworm or other insects feeding on your plants, that small investment ($3 to $20) in insecticide could pay off in a big way.