College of Agriculture, Food and Rural Enterprise (CAFRE) crops advisor, Leigh McClean, is recommending that farmers should apply second nitrogen on winter cereals by early stem extension.
Crops should also be inspected for recently emerged broadleaf weeds and top-up herbicide applied as temperatures warm up.
The advice is that all product labels should be checked for latest application timings, sequences with other herbicides and approved tank mixes with other products.
CAFRE advice on management
At a recent Co. Down update on fungicide performance, guest speakers Dr. Steven Kildea, from Teagasc, and Michelle Nuttall, from Agriculture and Horticulture Development Board (AHDB), confirmed the increasing importance of integrated pest management (IPM) in disease control.
Techniques, such as delayed drilling, selecting varieties or blends of varieties with good disease resistant profiles, and using diverse rotations are useful strategies to reduce disease pressure.
According to McClean, this approach will also help the fungicides we still have to work more effectively.
In winter barley, T1 fungicide timing aims to maintain tiller numbers. So growers should, therefore match application rate to the level of disease present.
McClean points out that a range of T2 fungicide can be applied around growth stage (GS) 39 – when flag leaf has fully emerged and first awns are appearing.
A mix of active ingredients are more effective than straight products. Teagasc trials on ramularia show both prothioconazole and mefentrifluconazole perform consistently better than other actives when applied protectantly.
In winter wheat, protecting leaf 3 at T1 (GS32-33) and flag leaf at T2 (GS39) are key spray timings for controlling septoria.
Mixtures containing new actives mefentrifluconazole (Revysol) or fenpicoxamid (Inatreq) give highest levels of activity but at a cost which is best justified at T2 and where disease pressure is high.
AHDB trials on yellow rust show benzovindiflupyr and prothioconazole (Elatus Era) are particularly effective. But all good mixtures perform well.
Folpet should be included as a partner in mixes to protect other fungicide groups as its inclusion slows the pace of disease resistance developing in both wheat and barley, according to the AHDB.
Turning to spring cereals, McClean indicated that growers should gradually increase seed rate up to 400 seeds/m² for spring barley over the coming weeks.
Weeds should be treated in all newly sown crops as soon as possible. In spring cereals, pre-emergence herbicides can help manage resistant broadleaf weeds such as chickweed and also target problem annual meadow grass.
Scheme
Meanwhile, Northern Ireland’s pilot Protein Crops Scheme has been retained for 2023. Once planted, effective weed control is key to good performance in peas and beans.
McClean confirmed that pre-emergence herbicide application provides the best control of broad-leaved weeds.
Post-emergent options are limited, they do not cover a wide spectrum of weeds and can be harsh on the growing crop.
