SUGAR BEET fungicide rates could be cut by up to half in low disease years with little negative impact on yield, according to latest trial results.

The Broom’s Barn trial carried out last year found that when disease pressure was low, the yield of plots treated with half the recommended rate of Opera (pyraclostrobin + epoxiconazole) was similar to those treated at full rate.

Compared to an untreated sugar yield of 13.3t/ha, plots treated with the full one litre rate of Opera averaged 14.54t/ha, while those that received half rate yielded 14.08t/ha, the trial showed.

But while there may be the opportunity to cut rates and therefore costs when conditions allow, it is hard to say that this will work everywhere, said BASF’s Andy Jones.

He believes the ‘greening effect’ that can be achieved from such products is particularly useful for growers with late-lifted beet, where crops have longer for the physiological benefits to come through.

“We would like to pin down the exact nature of these physiological processes,” added Broom’s Barn’s Eric Ober.

“It may be that the timing of the application could be fine tuned to maximise the effect, rather than being dictated solely by the disease.”

Plots treated with the product – which is the only sugar beet fungicide to contain a triazole and strobilurin – retained green leaves for longer than a fungicide-only treatment with sulphur, he noted.

“A reduced rate may be okay to trigger the required physiological effects, but a full rate is required where effective disease control is needed as well,” he said.