The prolonged spell of dry weather has been an excellent boost for farmers. Last years potato crop has at last been harvested and a large percentage of this season’s crop has now been planted. Most of the winter cereal crop has now had a T1 fungicide and any weeds present should now be controlled as crops race through the growth stages. The flag leaf is out on some crops of early drilled winter barley and although many crops are not very tall they should be assessed to see if a growth regulator is required. Some grassland spraying has been done over the last fortnight but temperatures are only beginning to stabilize now.

Grassland

Although the weather has been exceptional for the time of year grass has only begun to grow and the first cut is still a few weeks away. Fertiliser applications are only beginning to show now and it is important to allow one days growth for each 2-3 units of nitrogen between application and cutting. Failure to use up the fertiliser applied may result in poor fermentation due to high levels of non-protein nitrogen in the crop.

Docks are the most damaging weed which infests Northern Ireland farms. Part of the reason for the success of docks is that they will germinate and grow in almost any situation, and can then multiply by seed production or from underground roots. Seeds can be spread by a variety of means such as wind, water stock and machinery. More recently the spread of seed through slurry has become one the most common mechanisms of seed spread.

In most grassland fields there are approximately 12.5 million dock seeds per hectare in the top 15cm of soil and these can remain viable for up to 80 years. This seed bank provides an enormous reserve for reinfestation and reinforces the message that weed control is an ongoing battle not a one-off measure.

It is important to remember that grassland herbicides are only effective when grass and weeds are growing actively and should not be used when there is a risk of low night temperatures. 

The ideal time to spray docks is when they are in full leaf at the rosette stage just before the flowering stalk appears. Use plenty of water, about 30-40 gallons per acre, and do not spray in strong sunlight.  Products containing straight CMPP whilst effective on chickweed give only leaf control on docks.  For effective root kill it is necessary to use translocated herbicides such as dicamba, Fluroxypyr and triclopyr and allow sufficient time for them to move from the leaves down into the root system.  This is usually 3-4 weeks.  Examples of products, which contain dicamba, are Banlene Super, Grassland herbicide, Foundation and Dockmaster. Doxstar and Pastor contain both Fluroxypyr and triclopyr and are preferred on silage ground as they have little or no effect on the growth of grass.

Alternatively Forefront may be applied giving excellent weed control with no effect on the grass. Forefront contains Fluroxypyr and Aminopyralid, a completely new active, which is rapidly absorbed by the plant and may be grazed or cut 7 days after application. As well as controlling docks it will control chickweed, buttercup, dandelion, nettle and thistle.

Spot control of Nettles, Thistles and Docks can be achieved using Grazon 90 or Nushot.

Winter Barley

The growth stage of winter barley has never been more variable with many crops at (G.S 30-31) and some as far on as flag leaf ligule just visible (G.S.39).All crops should by now have received a T1 fungicide treatment. Starane XL may still be used if cleavers are a problem and Ally Max, Biplay or HarmonyM SX may be used up to flag leaf sheath extending. As the stem of winter barley begins to extend, the rate of growth is at its maximum, and during this stage it is most prone to manganese deficiency. If symptoms are seen, or the ground is known to have a history of the deficiency treat now.

Winter Wheat

Most winter wheat crops are somewhere between second and third node (G.S.32-33). Any remaining broad-leaved weed control should now be completed. StaraneXL, Ally Max, Biplay or Harmony M can be used up to flag leaf fully emerged. If wild oats are a problem and have not yet been treated, Cheetah Super can be used up to just before flag leaf sheath opens (G.S47) in the wheat, up to the end of stem elongation in the oat (G.S37).

Spring Barley

Most of the spring barley crops are now emerging and it essential to be aware of possible leatherjacket damage although the dry soil conditions will have slowed down their movement. To determine the threshold, examine ten 30cm lengths and if fifteen grubs or more are found you should spray with Dursban WG or Cyren. Aphid numbers will be high given the recent climate and all spring cereal crops should be protected with an aphicide. Sumi-Alpha should be applied at the 2-3 leaf stage to achieve effective control.

Weed control should be planned now with the aim of applying a herbicide as soon as possible. If applied before first node (G.S. 31) hormone weed killers such as Foundation, Compitox plus or Oxytril CM can be used alone to provide a cheaper option or in tank mix with Ally Max, Bi-play or Harmony-M to provide better weed control. Hussar now has a label use for spring barley and spring wheat. It may be applied from the three leaf stage of the crop controlling annual meadow grass, some broad leaved weeds and also suppressing cleavers and wild oats. Adjust should be used on spring cereals. Adjust applied early will maximize the suppression of the main stem development, and therefore divert nutrients and growth to promote secondary tiller development. This will help boost yield and reduce lodging.

Spring Wheat

Spring wheat’s are emerging well and similar weed control options are available as for spring barley.

Adjust can be used to increase tiller survival and reduce lodging. Applications made before or during tillering will have the biggest yield benefit.