Recently by Marion Self

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.

Moist conditions have evened crop establishment of second and later drilled wheats. After the rain, crops that are still emerging through heavy, cloddy seed-beds should be carefully monitored for increased slug activity.  

 

In winter cereals, dry conditions had reduced the impact of pre/peri emergence residuals. This has been apparent by high populations of volunteer rapeseed. However, following the long-awaited rain, crop volunteers are now clearly affected by the recent uptake of these residuals.  

 

Recent rainfall and mild temperatures have also prompted rapid grassweed emergence. Where significant grassweed populations have emerged, conditions are now good for sulfonylurea and residual activity.

Recent rain has evened up cereal establishment and oilseed rape growth. Where cereal drilling was stalled due to dry and hard soil conditions, the moisture has finally allowed cultivation of reasonable seed-beds.

 

Moist, friable seed beds are ideal for the activity of most pre- or early post-emergence herbicides. If any of these sprays have been delayed they should be applied swiftly before grass weeds emerge. In these conditions recently sown crops are likely to emerge quickly, however, they should be monitored carefully for slug damage until full establishment.

 

 

Cereals that have not been treated with an insecticidal seed dressing, such as Deter (clothianidin), should be protected from aphids and consequential BYDV infection using a foliar insecticide.

In the east more settled weather is forecast allowing growers to keep to their planned schedule of autumn work.

Warm autumn days and moist soils have encouraged good emergence and establishment of most rapeseed; even later-sown crops drilled into good conditions are growing well. Cereal volunteers and grassweeds will continue to emerge and should be controlled before becoming competitive with the crop.

Memories of last season's disappointing cereal yields are still raw. They were a result of unfavourable weather conditions, beginning with wet weather in late September which led to delayed drilling into difficult seed-beds. Consequently this season drilling of first wheats has begun in earnest as growers take advantage of good conditions.

Crops have responded well to recent rainfall with many looking greener and more robust. Whilst the availability of earlier applied nitrogen will improve grain fill, at best we can hope to maximise the remaining potential of each crop.

For milling wheats, assessing the need to apply a top-up of foliar nitrogen is difficult and may ultimately depend on the size of the expected premium. For lower-yielding crops, late nitrogen uptake may be enough to ensure that the required grain protein is achieved. However, higher-yielding milling wheats are more likely to require a top of foliar nitrogen to achieve specification, which can be applied until milky ripe.

Aphid colonies are present in both wheat and pulses. At the moment, populations in wheat are relatively low with an abundance of predators in many crops.  However, keep an eye on these populations as they could build quickly and move on to the ear if temperatures warm up. In pulses, if a second fungicide is outstanding check whether an additional aphicide is also required.

Recently many growers in the region have been taunted with the occasional, localised shower, but much of East Anglia remains parched. For some crops, particularly on light land or later drillings after roots the yield potential has slipped with every dry day. 

On the heavier land, despite the drought, crops have accessed moisture, but in many cases the applied nitrogen has not been made available leading to thin, pale crops with uneven growth. However, there are some exceptional crops, these are usually early September-drilled, or where fertility is high e.g. due to muck.  Many sugar beet crops are bearing up well, although on lighter soils these will soon need significant rain to support the top growth.

This year any cropped areas that are suffering due to poor soil structure or drainage can be easily identified and ear marked for remedial attention.  Damage to soil structure is particularly apparent after sugar beet; yield penalties from damaged soil structure and late drillings that may have been glossed over in recent years have become very apparent this season.

A gentle soak is needed. Following an exceptionally dry period with much of eastern England receiving less than 20 per cent of the normal recorded rainfall in March, crops are showing signs of drought stress.

These affects are becoming acute in some spring crops and second wheats on light or poorly structured soils. Dry conditions have hardened weeds, so robust doses of spring herbicides are required, particularly for fops and dims in spring crops and sulphonylureas for the control of brassica weeds and poppies in cereals.  

In cereals, fungicide programmes are well underway as final leaf three emerges in wheats drilled late in September. Dry conditions have restricted the development of septoria and eyespot infection. There is talk of responding to these conditions by reducing fungicide doses. But beware, there is still plenty of septoria, mildew and rust inoculum on the lower leaves. Well timed T0 sprays on rust-susceptible varieties have kept this disease in check.

Wheels have been turning during the last fortnight as drier weather has allowed good conditions for spring drilling and pre-emergence sprays. Many sugar beet crops were drilled during the second and third weeks of March and are now close to emergence.

Warming temperatures and recently applied nitrogen have accelerated crop growth, whilst increasing day length drives crop development forward. All wheat varieties are showing septoria lesions on their lower leaves. While septoria remains the dominant disease, our attention has been drawn to yellow rust, which is now widespread in the eastern counties on cultivars Oakley and Robigus.

After a false start in early February, we are eagerly awaiting a drier spell to continue with fertiliser applications and spraying.

Backward oilseed rape crops - those not treated during the dry spell - barley and late wheats are in need of their first dose of nitrogen and sulphur. While walking fields, it is clear that all crops are growing and ready to utilise some nitrogen -if only we could get near the field to apply it.

Hopefully, some of the earlier applied nitrogen stays within the root zone. Having just peeked at the weather forecast for the next fortnight, it seems that at best we can expect an unsettled period, remaining damp but turning milder towards the beginning of March. So a large peak of spring work lies ahead, especially for those growing sugar beet and other spring crops.

Growers have seized recent spray days and many have managed to complete the scheduled autumn applications although where soils are too wet there are still a few outstanding. 

In general, blackgrass pressure this autumn is lower due to a combination of factors including; later drilling dates, more opportunities for stale seedbeds and glyphosate pre drilling with successful pre emergence applications.

Growers still planning to apply autumn Atlantis should be mindful that while December and January applications can work well in milder conditions, the crop should be actively growing. Atlantis applications must be applied at a time that enables the spray to dry on the leaf before the evening dew settles; at this time of year these opportunities are rare. In marginal conditions or where resistance could be an issue good spray techniques are paramount.