Chemistry hots up for potatoes

Potato growers in the UK have two new fungicide options to use in their blight control programmes this year, both with the advantage of containing a new active ingredient from “a totally new class of chemistry”.

According to developer BASF, Initium has top class rainfastness as well as demonstrating foliar and tuber blight activity also.

Decabane has also performed well as a protectant fungicide, as it contains two top protectant actives.

Both products can be applied at seven to 10 day intervals and ametoctradin can be applied up to four times in any one crop. Both products will be important when it comes to resistance management, according to Phil Brown, agronomy manager for BASF.

Rob Storer, potato product manager for BASF, said Initium is the trademark of a new active ingredient with the common chemical name of ametoctradin.

“Initium is a highly effective protectant fungicide, showing premium preventative action against potato late blight. It has been coformulated with two other blight fungicides: Resplend contains ametoctradin plus dimethomorph and Decabane contains ametoctradin plus mancozeb. Developing coformulations with complementary active ingredients with different modes of action will enhance the products’ anti-resistance position,” he said.

“In addition Initium is from a totally new class of chemistry, the pyrimidylamines, which has no cross-resistance to any existing fungicides. Both Resplend and Decabane will be important new tools in the fight against both foliar and tuber blight as well as in resistance management,” Storer added.

BASF researcher Dr Kristin Klappach from BASF describes the discovery process for Initium and how its detailed mode of action was established.

Klappach also reviewed research into the mode of action of Initium. She said: “Initium cuts the energy flow of the fungus by inhibiting mitochondrial respiration (Complex III) at an unknown binding site within the cell. It shows no cross resistance to QoI chemistry as it works at a different site. We have also investigated its activity on zoospores, the causal agents of tuber blight in potatoes, and laboratory work clearly shows that it causes zoospores to burst within seconds of application and at very low concentrations. It also controls the infectious stages of the blight fungus and other oomycete pathogens.”