Oilseed rape yields could be boosted by up to 2t/ha if growers utilise appropriate green bud and early petal fall fungicides, according to UAP.
In trials last season, the autumn T0 contributed 0.3t/ha, the T1 green bud 1.5t/ha and the final flowering spray 0.5t/ha.
While the company acknowledged response is related to season and disease pressure, keeping the leaf stem and pod canopy green for as long as possible will help maximise crop potential, said technical advisor, Barrie Florendine.
“Each spray builds on the last to maximise productive canopies, prolong pod fill and boost yield. This year, the mild, wet winter has encouraged disease and growers need to select fungicides to target risks and – at green bud – to manipulate growth.”
Mr Florendine said the 1.5litres/ha rate of Agate (tebuconazole + prochloraz) worked well against light leaf spot and alternaria at T1, particularly on later-drilled and lower risk, low biomass varieties, such as Castille. It also shortened stems and encouraged root growth.
At petal fall, he suggested using 0.5-0.75litres/ha Agate, with 0.25litres/ha Filan (boscalid). In the trials this provided a margin over treatment cost of £60/ha, some £20/ha above the next best, he added.
“By ensuring good green leaf retention to maximise pod fill, growers can build on the green bud fungicide, as illustrated by the 0.5t/ha yield benefit in our trials.”