What is in this article?:
- 20 THINGS YOU NEED TO KNOW NOW
- 6 Raising corn is more of a gamble than playing blackjack.
- 7 The Amazon rainforest is not being cut down for soybean production.
- 8 Nearly all Midwest farmers have access to high-accuracy guidance networks.
- 9 More GPS brownouts are ahead.
- 10 Corn borer populations are rapidly shrinking in the Midwest.
- 11 Integrated pest management (IPM) isn't dead but evolving.
- 12 Glyphosate is applied too late.
- 13 Adding autoswath control to a sprayer saves 5 to 17% in applied product.
- 14 Assisted steering systems are no-brainers for return on investment.
- 15 It takes less fossil energy to produce ethanol than it takes to produce gasoline.
- 16 Ethanol does not take food away from people in developing countries.
- 17 Ethanol is not a water hog.
- 18 Livestock farmers are losing control of their animals.
- 19 Beef packs more nutrients into one 3-oz. serving than chicken does.
- 20 Small farms are not necessarily the most environmentally friendly option.
Glyphosate is applied too late.
THE BEST time to apply glyphosate to control early season weeds is when weeds are only 4 in. tall. Unfortunately, many producers wait too long to spray and end up losing important crop yield.
“If any weed population is present, it is critical to remove them when they reach 4 in. of height. For corn, that syncs well with the V4 growth stage,” says Jeff Gunsolus, extension weed science specialist at the University of Minnesota.
After that time, weeds can grow rapidly — as much as 1 in./day. “So in the course of a week, weeds can be up to 12 in. tall, and they are already starting to use quite a bit of nitrogen. In that time period, weeds can use 30 to 60 lbs. of nitrogen per acre that is not available to the corn plant,” Gunsolus adds.
Studies indicate that, after weeds reach 4 in. and are not controlled, corn yield drops about 3 bu./acre/day. “There is some potential to bring those nitrogen levels back up through sidedressing, but it is often not cost-effective,” Gunsolus says. “It's best to protect the nitrogen that is out there by controlling the weeds.” He recommends using a preemergent weed-control program with glyphosate. — Mark Moore