The superb weather over recent weeks has brought many crops much further forward than expected for the time of year. The awns are now out on most winter barley crops and orchards are in full bloom. Spring barley crops are emerging well and the need for an insecticide is essential as BYDV will almost certainly be a problem this season. Potato and vegetable planting are well under way and attention should be given to weed control options as timings very quickly pass. Silage cutting is due to begin this week in some areas but there may still be time to achieve effective dock control prior to first cut were grass is going to be cut later.

Grassland
Due to the early spring, silage cutting is already underway in some areas. Fertiliser applications were applied late 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 to 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 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 varies from (G.S.39) to (G.S.49).The opportunity to apply Cerone as a growth regulator may now have passed. Cerone can be applied up until before the awns are visible (G.S.49).Starane XL may still be used if cleavers are a problem. 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. Rhyncho and Mildew are present in most crops with some Net-blotch also showing, but levels of infection are low, reflecting the fact that T1 treatments were applied in good time, and disease pressure has been low over the past few weeks.

Winter Wheat

Most winter wheat crops are somewhere between third node and flag leaf just emerging (G.S.33-37). 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. The dry ground conditions we are experiencing will not allow the grub to move through the ground at speed yet they thrive in warm conditions. If treatment is to be carried out very high water volumes must be applied for the product to be effective. As crops emerge they are now showing signs of deficiency, the most common being potash, magnesium and manganese. This coupled with drought stress has crops struggling and the need to apply a foliar trace element spray is critical. CEREAL PLUS contains copper, zinc, manganese and magnesium. If potash deficiency occurs straight murate of potash must be applied.

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, Dockmaster,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.

Potatoes

With planting well under way consideration should now be given to weed control. Products containing Linuron should be used pre emergence of the crop and have residual activity. Performance of the residual herbicides is very dependant on soil moisture, and current dry conditions may hinder the performance of the product. Any ridging up should be done before application of a residual, as any soil disturbance after application will adversely affect performance. Emerged weeds will be controlled when application of the residual is delayed as late as its label allows, and a contact herbicide added. This also benefits the residual performance by allowing it to persist later into the season up to the point where the crop canopy will cover the drills and prevent further germination. Products containing Linuron should be used pre emergence of the crop and have residual activity.Gramoxone can be applied up to 10%emergence on seed crops and 40% on ware but has no residual activity.PDQ may be used, this is a Paraquat/Diquat mix and can be applied on earlies and seed up to 10% emergence and main crop up to 40% emergence provided the plants are no bigger than15cm high.Sencorex which is both contact and residual may be applied on specified varieties pre emergence up to when stems are 15cms in height. Alternatively Sencorex and Titus may be used up until the main stem is 25cm and an adjuvant such as Libsorb must be added. Where scutch is a problem in ware Falcon may be used.

Syngenta have launched a new potato herbicide this season, DEFY. Containing a new active, prosulfocarb, it is a residual with pre-emergent activity controlling a wide range of broad-leaved weeds and some grasses, with no varietal restrictions and safe in all soil types. It will be used as an alternative to linuron in combination with paraquat +/- diquat at early crop emergence. It does however have some important gaps in its weed spectrum including redshank, fat-hen and knotgrass, requiring the inclusion of linuron or SENCOREX to provide residual control of these weeds also. It has no post-emergent activity.

Horticulture

What a sight! Orchards in full bloom before the end of April. Although it has been unusually warm and dry there have been at least two scab warnings to date. The first in early March and the second a few weeks ago. Spray intervals should not be relaxed at this critical time and it is vital to apply chemicals which are gentle on the bloom. Most growers are using SCALA, TOPAS 100 or SYSTHANE at the moment mixed with a protectant fungicide. Mildew is present at low levels but will be controlled by using any of the above fungicides. Aphid numbers are extremely high and an insecticide will need to be applied post blossom to control both aphids and caterpillar.