There is an air of optimism as crops have come through the winter in good condition, promising good yield potential. The mild winter weather has had a huge impact on our agronomic starting point this spring; it has encouraged well tillered, forward crops, weed growth and disease development, whilst having little impact on aphid survival. The recent cold snap during the transition of January to February is unlikely to change the magnitude of these factors but may influence the pace of fieldwork in early spring.
Following the mild winter it is worth checking that all cereal crops were protected against BYDV infection (by seed treatment and or foliar sprays) into early November, at least. Any crops unprotected until this time could host aphids from an extended autumn flight bought about by mild conditions. As a precaution it could be worth controlling any overwintered populations in these crops before colonies expand and spread the virus in early spring.
Lush crops will need robust early season PGR strategies and disease susceptible crops will require early attention. Some of the first spring pesticide applications will include spring weed control in OSR for thistles, mayweed and cleavers with a clopyralid based spray e.g. Galera (clopyralid + picloram). In forward rapeseed crops the windows for this application is likely to be tight, catching crops as temperatures and day length increase but before buds are raised above the canopy.
Remaining post emergence grassweed applications e.g. Atlantis (mesosulfuron + iodosulfuron) should be applied once spring growth starts in earnest, targeting overwintered grasses whilst they are relatively small.
The T0 fungicide is typically applied at early stem extension (usually mid-March). This season yellow and brown rust pressure is already apparent (pustules in crops are easier to find than this time last season!). Most yellow rust susceptible varieties will receive a triazole holding spray during February to prevent disease build up prior to T0. In some instances it may be practical to mix an early triazole for rust control with the Atlantis (check the Atlantis spring tank mix guide).
Wheat bulb fly (WBF) risk is somewhat lower this season compared with spring 2011 as egg populations are approximately half and crops are well tillered. However, egg hatch has begun and “at risk” crops should be monitored carefully for WBF damage. If required egg hatch sprays, rolling, early nitrogen and later dead heart sprays can be deployed to reduce the impact of this pest.
N planning and N Max calculations should be completed in accordance with NVZ guidelines before any field applications are made. Fungicide prices are beginning to firm and growers should plan strategies based product performance and likely return on investment.