Early sowing of cereal crops and reduced seed rates have both increased the risk of Gout Fly attack this autumn. Fortunately, growers now have an effective treatment, with new approval for Hallmark Zeon applications during the critical autumn egg hatch, to protect against larval attacks. Crops emerging in September are at greatest risk, with Gout Fly now recorded as far north as Lincolnshire and across East Anglia.
Hallmark Zeon is the only foliar pyrethroid insecticide with approval for Gout Fly control, providing welcome relief for growers with early-sown wheat, barley and rye crops at risk of attack. Larval feeding activity eats into the heart of the crop over the winter, damaging developing tillers and preventing ear formation.
Syngenta Insecticides Manager, Michael Tait, advises growers to be on the lookout for adult Gout Flies, and inspecting crops for signs of egg laying on young cereal plant leaves. "Application timing, to coincide with egg hatch, is all important for effective control; for optimum results the window of application is about a week," he says. "Delayed application could result in reduced control."
Independent trials by ARC have shown Hallmark Zeon application giving a 50% reduction in the number of gouted plants affected by larvae attack, compared to untreated. In the trial, tau-fluvalinate - which does not have an approval for Gout Fly control - achieved just 15% reduction in affected plants. The results were confirmed by ADAS trials, where larval attack was reduced by two-thirds in the Hallmark Zeon plots, with yield increased by over 0.5 t/ha compared to tau-fluvalinate use.
Hallmark Zeon can be tank-mixed with most autumn herbicide and fungicide combinations. Mr Tait highlights the approved Hallmark Zeon rate of 50 ml/ha for Gout Fly will also provide effective control of the high aphid risk to early emerging cereals crops this year, threatening the extensive spread of Barley Yellow Dwarf Virus.
"This application rate will provide the greatest level of persistence for aphid control and a level of deterrence from re-infestation of the crop that is unique to Hallmark Zeon," he reports. "Mild weather could see the current high level of aphid infestation continue well into the autumn, so growers should be ready to continue treatment options whilst the threat of aphid activity is present."
Hallmark Zeon is also approved for control of the spring generation of Gout Fly during May, when spring and late drilled winter crops up to GS37 are at greatest risk.
