In the photo below, Jake Ulrich checks haylage at last fall's harvest. He used a foliar fungicide on alfalfa last season and saw yield increases.
Jake Ulrich’s yield increased by 20% on 90 acres of first-cutting alfalfa this past summer. He attributes that gain to a 6-oz/acre application of Headline foliar fungicide at about $14/acre, not including spraying costs.
“So we decided to spray pretty much everything on third crop except some stands that were getting older,” says the dairyman. Since leafhoppers were an issue by then, it was economical to apply the fungicide with insecticide. If heavy rains hadn’t prevented it, Ulrich would have put the product on second crop, too. His third-crop yield increase: 10%.
Headline, manufactured by BASF, was labeled for use on alfalfa in 2010. It’s promoted as a way to increase yield and forage quality. But university trials looking at yield haven’t been as conclusive as Ulrich’s or the BASF research program in which he took part.
Ulrich farms 600 acres of alfalfa, 150 of reed canarygrass and 1,100 of corn and milks 1,000 cows in partnership with his brother, Justin, and cousin, Corey, near Dresser, WI. As the value of hay increased, their agronomist suggested that they consider applying Headline.
They took part in a 2012 BASF program testing the fungicide and worked with Sam Burgess, BASF business representative. Its product label states that it controls several leaf spot diseases, powdery mildew, rust, anthracnose, Rhizoctonia and yellow leaf blotch, among others.
“In the state of Wisconsin, there were probably 60,000 acres of Headline sprayed on alfalfa last year,” Burgess says. “On a dry matter basis, anywhere between 10% and 20% yield increases typically were what we were seeing, and that’s pretty much across whether it was first crop or fifth crop.”
The fungicide was applied to established stands and new seedings, he says. “One thing we are seeing is, maybe in an older stand, it’s keeping the stem counts high. Rather than having to pull your stand out because you’ve got a low stem count, it’s increasing those stem counts. So it may be increasing the longevity of the stand depending on the kind of management.”
University trials, however, aren’t showing consistent yield gains, says Bill Halfman, University of Wisconsin Extension ag agent in Monroe County.
“From all our locations, it’s been variable; it has not been consistent in whether we see a response or not,” he says. University of Minnesota (U of M) Extension researchers joined forces with Halfman and his colleagues after each group had conducted one year’s worth of trials on the fungicide in 2011. Three Wisconsin research trials – at Arlington, Tomah and Waupaca – and two Minnesota trials at Waseca and Rosemount were compared in 2012.
“All of our locations have been small, replicated plots 20’ wide by 30’ long. We’ve been putting out four different treatments: an untreated check, Headline alone, then we have an insecticide alone and an insecticide and Headline together. Warrior or a similar insecticide was used,” Halfman says. They applied the recommended 9-oz/acre rate of the fungicide.
Minnesota’s one-site 2011 trial saw up to a 20% positive yield response, says Lisa Behnken, U of M regional Extension educator in crops. “It meant we saw something – one site, one year. And there were some circumstances that went with that – a delayed first cutting because of rain, the amount of disease, etc.”
But Wisconsin trials that year brought little response. The 2012 results at the five Minnesota and Wisconsin locations were variable, Halfman says. Take, for instance, first-cutting results comparing the untreated check to Headline:
“At two of the locations, we saw a statistically significant yield increase in the Headline treatment. We’re looking at anywhere from around 0.22 ton of dry matter per acre to less than two-tenths of a ton. The other three locations, there were no differences in yield.”
Comparing the insecticide-treated plot of first-cutting alfalfa to that sprayed with insecticide and Headline, none of the locations showed additional yield, Halfman says. “Actually, at one of the locations, the insecticide alone had a statistically greater yield than the fungicide did. There are a whole lot of factors that influence yield out in alfalfa fields. Disease is only one of those factors.”
Behnken points out that the dry 2012 growing season may have limited the response.
“It was a very dry year, and we’re speculating that, when you’re on a 35-day cutting schedule, the diseases don’t have as much of an opportunity to get established and cause yield loss,” she says. “If you’re on a 45-day schedule where you’ve got a bigger window for disease to set in, you start to see more leaf loss and the fungicides have an opportunity to do what they’re supposed to do.”
That wasn’t the case in Ulrich’s area, which is 70 miles north of the closest university trials at Rosemount and received heavy rains. “We were very fortunate last year to be in an area that got the rain. We were able to take five crops of hay. The heavy rain might have played a big part in the success that we have seen. Aren’t wet areas where you are going to see a lot more disease, anyway?”
The fungicide should beapplied when alfalfa is about 6” tall – and little disease can be sighted. The 14-day harvest interval makes it challenging for growers who want to cut on a 28-day schedule for dairy-quality hay, says Halfman. “We found that you cannot be monkeying around. It’s going to take 10-14 days for it to get to 6” tall and then in another 14 days, give or take a little bit, it’s ready to cut again for dairy-quality hay.”
The university trials also looked at forage quality, but results there weren’t conclusive, either, Halfman says. Looking at Headline vs. the untreated check plots of first-cut alfalfa across all five locations, two locations showed slight increases in protein and net energy lactation percentages. “We can say it appears to be real, but, for instance, for one site it was only a 2/10% increase in protein and the other was a 4/10% increase.”
One of the other three sites actually showed a slight decrease in quality on the Headline-treated plot. “We had very inconsistent responses,” he says.
Comparing the first-cutting plots treated with insecticide vs. insecticide plus fungicide, one location had a quality increase with Headline, one showed a decrease and three showed no quality differences.
Ulrich also took a feed analysis on treated and untreated alfalfa. “We can’t really say we see anything more as far as the feed quality goes. But we can definitely say that the tonnage is there and pencils for us right now.”
He plans to apply the fungicide on first-cutting alfalfa this coming season. It will depend on rainfall levels whether he treats subsequent cuttings on any but his irrigated alfalfa.
The researchers hope to continue studying the use of the fungicide on alfalfa and offer economic guidelines as to when it does or doesn’t pay to apply it, Halfman says.