Although “it seems clear” that foliar fungicides such as Headline reduce levels of foliar disease in alfalfa, that doesn’t consistently translate to higher yields or quality, say two University of Kentucky (UK) Extension specialists.
Headline was labeled in 2010 for control of foliar diseases on all alfalfa production – for seed, hay and haylage – with a 14-day pre-harvest interval.
UK plant pathologist Paul Vincelli and forage specialist Ray Smith reviewed results from two dozen public field experiments evaluating strobilurin fungicides around the country from 2010-2012. The active ingredient in Headline, pyraclostrobin, is in the strobilurin family of fungicides, “also known for sometimes improving the overall physiological health of plants,” Vincelli and Smith report in a May edition of UK’s Forage News.
In research conducted thus far, the fungicide was associated with increased forage yield in only about 20% of comparisons. And forage quality was not meaningfully improved by applications, the Extension specialists write.
“This latter finding surprises us. We would expect that improved leaf health would translate to improved forage quality, since leaves represent high-quality forage.”
One caveat: Last year’s weather was unusually dry. Vincelli and Smith say further research is needed to determine whether using fungicide in wet growing seasons might be “economically favorable.”
For a Wisconsin grower’s perspective on Headline fungicide, read “Maximizing Alfalfa Yield With Fungicide.”