Ask an Agronomist Day 1: Weed Management
The Agronomy Bar at the Syngenta booth at Farm Progress Show 2023
At this year’s Farm Progress Show in Decatur, IL, Syngenta agronomists hosted daily Ask an Agronomist sessions to answer your most pressing questions. In case you weren’t able to make it, we’ve compiled some of the top questions and our agronomists’ answers. Our topic for day 1 was weed management:
Q: Given the tough drought conditions this season, especially early on and during planting, what is your advice on managing weeds when you don’t receive any activating rain to help your herbicide perform well?
A: If you don’t receive an activating rain, the best advice that I can give is don’t wait to respray. Some folks want to wait until you get a rainfall to get the initial herbicide activated. I would recommend getting the weed sprayed when they’re already 2 to 3 inches tall to make sure you kill that flush as well because trying to control foot tall weeds is not going to be very effective.
Q: When it comes to soil and nutrient management, what nutrients can help increase corn kernel size and density?
A: Nitrogen is the most critical as far as impacting kernel size and development. Good solid nitrogen management. Some nitrogen in the fall, some nitrogen in the spring is always a good way to manage nitrogen, and then ultimately, we need to keep the fields weed free so the weeds aren’t consuming the nitrogen and taking that away from your crop. That’s an important part of applying a pre herbicide. If you do a post only herbicide program, those weeds are going to take up some of that nitrogen early in the season and you won’t get that back.
Q: What are some of your top tips for helping stop weeds before they can germinate and potentially overwinter?
A: If you’re approaching harvest and you have weeds in your field still, unfortunately you’re going to have to go out and pull those weeds and prevent the seed from redepositing back into your seed bank, and it’s going to be a problem going into the future as well.
In addition to that, we would consider a fall herbicide to control weeds like marestail, dandelion, some of your early season winter annual weeds. Controlling them in the fall is the most effective way to set yourself up for the 2024 season. And if you do have a field that has a lot of weed escapes, plan ahead for that for the next growing season. Maybe put a little bit heavier rate of a pre herbicide down, and maybe a higher post rate as well, within labeled application rates.
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