Bruce Schultz, Gould, Frances I.
Amistar Top, a new fungicide, made its debut in 2018 with mixed reviews.
Some farmers gave it a thumbs-down because their fields were hit with heavy concentrations of sheath blight.
“Some people had good experiences, and some people had bad experiences with it,” said Don Groth, an LSU AgCenter plant pathologist. “As with any new product, we learned a lot.”
He said testing had been done on strip plots using ground-rig sprayers that allowed for good penetration into a plant.
“It performed very well in these tests,” Groth said.
Spraying Amistar Top earlier — at five days after panicle differentiation — was more effective than the usual boot stage because the canopy was more open, allowing the fungicide to penetrate the understory of the plant canopy, Groth said.
He also said Amistar Top’s effectiveness seemed to improve when it was mixed with Tilt fungicide, an emulsifiable concentration that may act as a surfactant and help spread more of the product into the lower canopy.
“In one trial this year, where Amistar Top’s control was poor, yield was as high as better-performing fungicides,” Groth said. “We are planning next year to have an extensive program to find the best ways to use Amistar Top.”
Don Groth, an LSU AgCenter plant pathologist,
talks at a field day near Rayville about using
a T stick to scout for disease. Groth said the
new guidelines are being developed for a new
fungicide, Amistar Top.
The LSU AgCenter and the LSU College of Agriculture