Beet fungicides vital to preserve crop potential
Be ready to use sugar beet fungicides next month to preserve the potential of this season’s generally good looking crops.
That is the message to growers from several sources.
Only where farms have drilled rather too much to guard against not meeting quota might at least one spray to control powdery mildew, rust and ramularia not be justified, say agronomists.
About 70% of growers apply fungicides, but more could usefully do so, if only to appreciate what they could be missing, says Broom’s Barn’s Mike May.
The forecast for attacks by powdery mildew, the most yield-sapping disease, is relatively low.
“It will probably come in a bit later.
But with the right conditions it can soon take off.”
The main difference this season is that first treatments might not be needed until August, he explains.
Fungicides are key inputs under the current price regime, says Norfolk-based John Purslow of the AICC.
“Yield potential this year is good, as crops have been intercepting maximum UV light for some time.
“My advice would be to use a fungicide across the whole crop and to contemplate a second one for crops that are going to be lifted post-Christmas.
I’d like to see a triazole on every acre because of the greening effect.”
Pat Turnbull, another AICC beet specialist, echoes that view.
Growers with reduced acreages because of quota cuts could have higher yield targets this season, she points out.
Most rhizomania-resistant varieties are particularly sensitive to rust, adds Mr Purslow.
“With all beet varieties it’s not a case of whether to apply a fungicide, but when,” says Hilleshog’s Richard Powell.
“All growers should be using a fungicide, as much for the physiological greening and yield effect as for disease control.
Independent trials have shown yield gains of at least 5% even under low disease pressure.”
BS trials have repeatedly highlighted the value of early powdery mildew control, he notes.
Varieties with good late-season disease resistance, particularly to rust, may merit only one treatment, especially if using the new persistent Spyrale (difenoconazole + fenpropidin), he says.
