Farmers should have a new fungicide in 2020 or 2021.
“It will be similar to Sercadis and Elegia with the same mode of action,” said Don Groth, LSU AgCenter plant pathologist.
“Sercadis is not on the market any longer, and this new product will give farmers another option,” he said.
Groth said it will be effective against the strobilurin-resistant sheath blight fungus and wild types.
Additional work on Amistar Top this year failed to show any great increase in effectiveness, he said. Amistar Top showed promise in three years of testing in small plots treated with the chemical sprayed in backpack sprayers.
Amistar Top was first used commercially on rice in 2018 with disappointing results after applications by aircraft.
More testing and refinement in 2019 showed no better results, he said, even with different timings and rates.
“We didn’t find that silver bullet to make that product work as well as we hoped,” he said.
Although disease control was not as good as other products, yield increases were comparable.
Amistar Top worked best with an application at boot and again at heading, and it also had effectiveness when it was used sequentially with Elegia, but Groth said either option is considerably more expensive.
However, Amistar Top does have a practical fit for second-crop rice, he said, and the product is labeled for that use.
The LSU AgCenter and the LSU College of Agriculture