Grain aphid build up demands rapid knock-down
Cereal growers and agronomists are advised to be on the lookout for grain aphid numbers building up on ears during the final grain fill phase, particularly when the weather returns to hot and dry.
Whilst cooler and wetter conditions will have helped to limit pest pressure over recent days, populations have already been identified on crops across England and Ireland, with the seasonal indicators pointing to higher numbers developing, warned Syngenta Technical Manager, Dr Max Newbert.
He cited previous years of serious issues with grain aphid have occurred where the preceding season’s grain aphid population had been low and where temperatures had been cold over winter, but at least 13⁰C in spring.
“Those conditions have been met this season, along with current humid weather conditions that reach no more than 30⁰C, which all favour grain aphid development,” he added.
Dr Newbert advocated that where populations are seen to be increasing, in both the number of aphids and their maturity, that would indicate rapid multiplication and spread, an application of Hallmark Zeon can achieve fast and effective results.
“Its rapid knock-down contact action is the preferred option during the latter part of the crop’s growth stages, when any movement of systemic products in the plant is limited,” he reported.
Trials have shown Hallmark Zeon is especially effective on grain aphid, achieving more than 90% control, with very good infield performance on the minority group of resistant grain aphids.
Sprayer operators should pay attention to speed, water volume and boom height, to maximise spray retention on the ears and target hard to hit aphids amongst the grains, particularly on wheat and six-row barley, urged Dr Newbert.
“One well timed and effectively applied spray now, could protect the crops' yield potential through to harvest,” he advised.