New wheat fungicide anticipated in disease resistance battle

Winter wheat growers could soon have a fourth group of systemic fungicides in their armoury to control septoria with the development of a septoria-active strobilurin.

This will help in the fight to delay disease resistance to fungicides.

In the early 2000s, the strobilurins were overused and often used on their own – and soon septoria built up resistance.

However, agrochemical giant BASF is trialling a new strobilurin, Pavecto, with very good activity against septoria, for launch later this decade.

Marco Moorfeld, the group’s vice-president of market management agricultural solutions, says the product has overcome the strobilurin resistance problem.

Its development also comes at the good time with the number of fungicides being banned.

″Strobilurin chemistry is back in the game for controlling septoria leaf blotch, and trials with the product in Western Europe have been very successful,″  he tells Farmers Weekly.

Following Revysol

The group is reluctant to give a likely launch date due to possible delays in getting official approval.

But it hopes the product will be available in the next few years to follow on from its success with its new azole fungicide Revysol (mefentrifluconazole).

Wheat growers currently have three groups of systemic fungicides to control septoria, namely azoles, SDHIs and picolidamides.

Therefore, a septoria-active strobilurin would be a welcome addition to prevent disease resistance building up against fungicides.

It would open up the possibility of wheat growers, who use a basic T1 and T2 fungicide regime, being able to use two products from different groups for each of the two spray timings.

This would mean they can avoid using the same chemistry twice in a season.

The new strobilurin is anticipated to be mixed with a partner – the most likely being BASF’s existing azole Revysol or its SDHI fluxapyroxad – and Mr Moorfeld says any new mixed products will be better than existing ones.

But he points out that a Revysol-Pavecto mix would create a very strong product.

″New tools need partners to protect the fungicides, and the better the partners the better the resistance management,″ he says.

Rust control

Strobilurins, known also as Quinone outside inhibitors (QoI) for their mode of action in attacking an unwanted fungus, also give good control of rusts and have a greening or physiological effect on plants.

However, this new strobilurin is not seen as a rust-specific product while its greening effect is still being assessed.

The new product is being jointly developed by BASF and Japanese group Sumitomo Chemical.

The German chemical group is hopeful of introducing four new active ingredient this decade, which would be unique for the company.

These include two already launched, namely Revysol and Luximo (cinmethylin) herbicide, and the still-to-be launched products Pavecto and insecticide Axalion.