Crop Crack

The recent unsettled weather and localized heavy showers are beginning to take their toll on all crops. Continued Blight outbreaks have been reported over the last week and spray intervals should be kept to no more than 7 days with the current high risk weather. Very few winter barley crops have been harvested but hopefully a more settled spell will allow the remaining acreage to be cut. Average yields from winter barley crops are as expected, given the poor conditions in late spring/early summer.

Potatoes

Where crops have reached the end of rapid haulm growth and canopy growth has begun to stabilize good protection may be achieved with fungicides such as Invader, Infinito, Ranman and Revus. Option which is straight cymoxanil may be tank mixed with any of these products to achieve better kickback. Curzate has good curative activity and may be tank mixed if the spray interval is stretched. Where crops are at full canopy growers must pay very close attention to ensure water volumes, spray pressure and nozzle selection are correct to maximize spray penetration of the haulms and reduce spray drift.

Cereals

As harvest begins the most widely used grain preservative, Propionic acid, will be in demand, especially if showery conditions continue coupled with high levels of fusarium present on crops. Propionic acid when applied to moist grain prevents moulds and bacterial activity. It also prevents deterioration, loss of dry matter, nutrition loss and removes the associated health hazard to grain handlers, livestock and the end user.
One tonne of Propionic acid on 100 tonnes of grain gives an additional energy value equivalent to 1.5 tonnes of barley. Therefore as well as preserving the grain it adds significantly to its energy value. The use of Propionic gives the grower greater flexibility at harvest, especially if the grain has a higher than desirable moisture content. If the weather is inclement at harvest Propionic acid offers a sense of security to the grower through its flexible application rates. Over the last few years the benefits of increased starch in the diet of dairy cows have been shown. The most noticeable is the improvement in milk protein percentage, resulting from the breakdown of starch in the rumen to Propionic acid. In order to take advantage of the benefits of increased cereal feeding and the inherent cost benefits, many farmers are making use of home grown cereals in a number of ways: whole crop wheat, maize silage, crimped cereals, dried grain or rolled moist grain. However one of the main problems arising from this increased storage and use of home grown cereals is the growth of moulds and the subsequent development of mycotoxins. Propionic acid is a natural organic acid, which also occurs naturally in the animal’s digestive system. It halts all mould growth when applied to moist grain. If a product can be augered it can be treated – barley, wheat, oats, maize, peas – whole or rolled it makes no difference. However it is essential to increase the application rate of acid when treating rolled grain as this increases the surface area to be treated and also exposes the starch which is more difficult to preserve.
Propionic Acid has an energy value of 1.5 times that of barley so as well as preserving the grain it also adds to its energy value. With Propionic Acid treatment, harvesting can take place when there is still surface dampness on the grain, dew or rain. Harvesting can start earlier in the morning or after rain and continue later at night, giving a quicker more flexible harvest, which leaves extra time for autumn cultivations. By harvesting before grain is fully ‘ripe’ a higher yield is also obtained, reduced shedding losses may save 200kg per hectare.
Natural vitamin E levels in moist grain, whether treated or not, are destroyed during storage. When moist grain forms a major part of the diet a mineral/vitamin supplement high in vitamin E should be used.
Propionic Acid treated grain can be stored simply on a dry floor. It should not be stored with untreated grain.

PROPIONIC ACID APPLICATION RATES

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The recent unsettled weather and localised heavy showers are beginning to take their toll on all crops. Blight has been reported over the last week and spray intervals should be kept to no more than 7 days with the current high risk weather. Very few winter barley crops have been harvested but hopefully a more settled spell will allow the remaining acreage to be cut. Fusarium is very pronounced in both winter wheat and spring barley this season.When weather conditions are wet during flowering, high levels of ear blight can occur.

Potatoes

Where crops have reached the end of rapid haulm growth and canopy growth has begun to stabilize good protection may be achieved with fungicides such as Invader, Infinito, Ranman and Revus. OPTION which is straight cymoxinil may be tank mixed with any of these products to achieve better kickback. Curzate has good curative activity and may be tank mixed if the spray interval is stretched. Where crops are at full canopy growers must pay very close attention to ensure water volumes, spray pressure and nozzle selection are correct to maximize spray penetration of the haulms and reduce spray drift.

Cereals

Winter wheat, spring barley and winter oats are all ripening quickly. These should be examined to decide whether or not they require pre-harvest treatment with ROUNDUP ENERGY for the control of annual and perennial weeds especially scutch, rough stalked meadow grass, thistles

etc.ROUNDUP should be applied when the grain moisture is below 30% which coincides with the hard dough development stage (GS.87). The safest time is 1-3 weeks prior to harvest leaving at least 7 days between spraying and harvesting. (DO NOT APPLY TO SEED CROPS).

Propionic Acid

As harvest begins the most widely used grain preservative, Propionic acid, will be in demand, especially if showery conditions continue. Propionic acid when applied to moist grain prevents moulds and bacterial activity. It also prevents deterioration, loss of dry matter, nutrition loss and removes the associated health hazard to grain handlers, livestock and the end user.

One tonne of Propionic acid on 100 tonnes of grain gives an additional energy value equivalent to 1.5 tonnes of barley. Therefore as well as preserving the grain it adds significantly to its energy value. The use of Propionic gives the grower greater flexibility at harvest, especially if the grain has a higher than desirable moisture content. If the weather is inclement at harvest Propionic acid offers a sense of security to the grower through its flexible application rates.

Grassland

Weeds are directly competitive with grass and in many cases reduce the nutritional value of the sward. Annual weeds are most commonly a problem in getting a reseed established but thankfully few persist once the sward has been grazed or cut. The most common weed that this does not happen with is common chickweed. Chickweed will reduce dry matter and slows wilting. This causes loss of soluble nutrients in the field and as, effluent from silos. Docks are a perennial weed and have large leaves and substantial tap roots which they can readily regrow if defoliated. Docks thrive in high nitrogen conditions and along with chickweed need to be treated every year to ensure good control.

Where possible weed infested grass fields should be treated as soon as possible. Forefront, Doxstar and Pastor will give good control of docks but will not check the growth the grass.Use high water volumes to ensure good coverage i.e. 300-400lt/ha. Gorse should be sprayed now. Use Grazon 90 and ensure good plant coverage using a knapsack or hand lance on a tractor mounted sprayer. Bracken should be sprayed late July or August when it is in full frond. (When leaves are expanded). Use Asulox and again ensure good coverage via a knapsack and where a conventional tractor sprayer is being used to treat large areas, use high water volumes at least 400l/ha

The weather continues to be very unsettled. Growth has been good over the last number of weeks with most crops looking well, but spray days have been difficult to find and many crops have not been sprayed at the correct timing due to the absence of a suitable spray window. Blight is reported in many areas across the province. Rhynchosporium is present on almost all crops of spring barley. I would advise under current disease pressure to ensure spring barley crops get a robust T2 fungicide and winter wheat an earwash .SUMIALPHA should also be included at this time.

POTATOES

Alternating between different products with different modes of activity is an essential part of an anti-resistance strategy. As levels of blight inoculum build over the course of the season, so growers must guard against the possibility of the fungus becoming resistant to the chemistry used – overuse of any one product will increase the likelihood of this dramatically. Continue therefore to switch between products from different chemical classes that are active on zoospores, so providing the best protection against tuber blight.
Product Types and Mobility in the Plant

There are three different ways by which the blight fungicide moves through the plant:
Contact fungicides eg. DITHANE, RANMAN, SHIRLAN, TIZCA – these products protect only the outer surface of the leaf onto which they are deposited. They do not move into the leaf and therefore do not normally protect any new growth that emerges after application.
Translaminar fungicides eg. CURZATE M WG, HARPOON, INVADER, RESPLEND, REVUS – these products move into the leaf onto which they are sprayed and then redistribute throughout the leaf tissue as it increases in size. They become rain-fast once they are in the leaf.
Systemic fungicides eg. CONSENTO, FUBOL GOLD, INFINITO – these products move in through the leaf surface and upwards into the new growth that emerges between applications, protecting that new growth from infection also.
Last year BASF brought to market a new active ingredient from a novel fungicide group, ametoctradin. This active has excellent activity against foliar and tuber blight and is rainfast in less than 1 hour. It moves into the leaf and is redistributed to the growing margins, so protecting the leaf as it grows in size. It also binds strongly to the waxy layer on the surface of the leaf and is redistributed over the surface onto new forming leaves. This makes the product ideal for use during the rapid canopy phase. To manage resistance, the active is co-formulated with more than a full rate of dimethomorph (relative to INVADER) and marketed as RESPLEND. The dimethomorph brings excellent curative activity to the product also and makes the product well suited right through the stable canopy phase.

Product Selection and Growth Stage

Early canopy development phase, emergence to rosette – Products that have zoospore activity are the most effective 1st spray, applied at the rosette stage prior to rapid haulm growth. RANMAN, SHIRLAN or TIZCA will control any zoospores that may be in the soil (either from ground-keepers or infected seed) and provide good protection of the new plant. Rapid canopy development phase, end rosette to beginning tuber initiation – Because of the considerable amount of new growth being produced during this phase, it is essential the product being used is fully systemic to properly being put on between applications. Later planted crops are higher risk as they produce more new growth between applications than earlier planted crops, at a time when the level of inoculum in the air is progressively increasing. Of the fully systemic fungicides, only those based on propamocarb effectively control all genotypes including the A2-13 strain. With the withdrawal some years ago of MERLIN & TATTOO, CONSENTO is the only fully systemic in the marketplace, containing propamocarb and fenamidone. The fenamidone adds a different mode of activity and builds in early tuber blight activity also.

Late canopy development, tuber initiation phase -As the crop canopy closes across the drills, the crop starts to initiate tubers. From this point on these daughter tubers are vulnerable to infection, so fungicide selection must also consider introducing tuber blight control, spread by zoospores being washed off any infected leaves or stems. At this stage INFINITO should now be introduced. Being fully systemic and translaminar it continues to protect new growth, and being curative it provides kickback should any foliar/stem blight appear. INFINITO remains one of the highest rated of the 21 products compared by the Euroblight group last year.

Canopy stable, tuber bulking phase -The need for systemic activity diminishes as the rate of haulm growth slows down during the mid season tuber bulking phase. Tuber blight activity should also become a factor as tuber development gets underway.Having tuber blight activity INFINITO is an ideal choice at this time also, but because it is limited to a maximum of 4 applications, 1 or 2 applications should be kept back to apply when severe pressure comes on, mid or late season.Other excellent alternatives at this time are INVADER & RESPLEND. The dimethomorph component of both products is curative and very persistent within the leaf and stem, so both are ideal alternatives when pressure is high. Both are translaminar, protecting the foliage as it fills out. The maximum dose for dimethomorph has been increased from 150gm/ha to 180gm/ha, both products now putting this higher rate on at each application. This has further improved the kickback and persistence of both products.
If the spray interval becomes unavoidably stretched by a day or two beyond 7 days, HARPOON should be tank-mixed at full rate along with whatever product is being used to provide the kickback effect this product gives. HARPOON is cymoxanil and is the most curative active available, meaning it will control any latent infection that may already entered the leaf as a result of the delayed application. However it breaks down within 3-4days after application, hence it must only be applied in mixture with another fungicide when curative activity needs to be maximised.

Improving Rainfastness

If spraying during periods of unsettled weather, rainfastness of all products will be further improved with the addition of a sticker to the spray solution. GUARD is a latex sticker and will improve the retention of the fungicide onto leaf surface, so improving both adhesion onto the leaf immediately post application, and over the following days should rainfall levels remain high.

General Comments on Good Practice

Never use any blight product at reduced rates; to do so will seriously compromise its performance, reduce its persistence, and encourage the selection of blight resistance.
As most products are either contact or translaminar only, coverage of the maximum surface area of the plant is critical. Maintain water volumes of at least 200lt/ha from the start to ensure good coverage, increasing to 300lt/ha in very leafy crops later in the season.
Make sure nozzle type used is correct to ensure sprayer pressure, droplet size and water volume applied are as per the label; these factors are as important product choice in terms of achieving good coverage of the foliage. Inspect and calibrate nozzles regularly to maintain performance. Trials have shown that fitting angled nozzles alternating to face forwards & backwards along the boom gives better coverage of the plant and significantly reduces drift.

Maintain boom height at correct height above the canopy throughout the season to ensure correct spray pattern and minimise drift; 50cm for 110° fan nozzles spaced 50cm apart.
Do not spray when leaves are wet as this will significantly increase the likelihood of runoff, so reducing the amount of active retained on or into the leaf .Make sure points and areas around line poles are fully covered. Inspect crops regularly throughout the growing season to identify any outbreak early, and determine growth stage. Use this to assist with product selection.

Trace element deficiencies

During the main canopy development phase the rate of new growth is extremely rapid. This places a huge uptake demand on the uptake of all nutrients, and in conditions of such rapid growth any nutrient that is limited in availability will suppress haulm growth, and as tuber initiation begins, tell the plant to form fewer tubers also. Manganese, sulphur and magnesium are three of the potentially most limiting trace elements, and timely application of these nutrients in an immediately available foliar formulation will offset this yield limiting effect.So that the crop is not adversely affected, it is essential to apply 2-3 maintenance applications of Mn, S & Mg along with N before symptoms are seen, the first going on at the onset of tuber initiation, which normally coincides with about 30-50% ground cover.

Slugs

The damp spring has been ideal for slugs, so there is an increased risk of slug damage this season on crops in heavier ground. The damper soil encourages slugs to come up to the soil surface, so providing the ideal opportunity for good control. The key timing for effective slug control is just before the crop canopy meets across the rows. Miss this timing and the control will be less effective regardless of how many times they are treated. Take advantage of any rainfall by applying pellets just after rain when the slugs move up onto the soil surface, Potato varieties particularly susceptible to slug damage include Maris Piper, Desiree and Kerrs Pinks

After another mixed bag this week conditions remain ideal for many diseases. Blight pressure remains high with the first outbreak of the season confirmed by AFBI earlier this week.Where potato crops are at the main canopy development it is essential the product being used is fully systemic to properly protect the new leaves being put on between applications. Later planted crops are higher risk as they produce more new growth between applications than earlier planted crops, at a time when the level of inoculum in the air is progressively increasing.
During the main canopy development phase the rate of new growth is extremely rapid. This places a huge uptake demand on the uptake of all nutrients, and in conditions of such rapid growth any nutrient that is limited in availability will suppress haulm growth, and as tuber initiation begins, tell the plant to form fewer tubers also. Manganese, sulphur and magnesium are three of the potentially most limiting trace elements, and timely application of these nutrients in an immediately available foliar formulation will offset this yield limiting effect. So that the crop is not adversely affected, it is essential to apply 2-3 maintenance applications of Mn,S & Mg along with N before symptoms are seen, the first going on at the onset of tuber initiation, which normally coincides with about 30-50% ground cover.
Aphid’s damage potato plants directly through feeding damage and indirectly by transmission of several viral diseases, of particular importance in seed crops – aphid control is necessary on seed crops to prevent the spread of potato leaf-roll, mild and severe mosaic viruses. Aphids are the vectors for these viruses i.e. it is the aphids by their feeding action which pass the virus on from one plant to the next.
A number of different species of aphids are responsible for viral spread. When checking plants for aphids, look at both sides of leaves at all levels of the canopy, and monitor the whole crop, not just the headlands. The crop is most vulnerable to virus transmission at the early growth stages, so it is vital to control once aphids are seen – the early sprays are much more important than later treatments in limiting virus spread.
BISCAYA controls all important aphids, including MACE resistant species, by both its contact and systemic modes of action. Central to its efficacy is its penetrant which greatly improves retention on the leaf. The oil forms a film after the water has evaporated, enhancing penetration of the active ingredient, thiacloprid, into the leaf, thereby speeding and prolonging activity. BISCAYA provides the same degree of efficacy in the mid-canopy leaves of the potato plant as on the upper leaves, still providing over 90% control 14 days after application. As a resistance management strategy its label allows only one application in ware crops and two in seed. In order to minimise the possibility of resistance developing, other aphicides with different modes of activity should be included. BISCAYA should be used first in the control programme to take out any aphids resistant to other approved aphicides.

Spring Barley

Ramularia (also known as leaf spot) is widespread in spring barley with the newer barley varieties showing more sensitivity to this late developing disease. It shows itself late on in the season (usually after booting), symptoms are very similar to manganese deficiency appearing as brown necrotic speckling on the upper leaves. Symptoms appear where crops are subjected to stress from alternating periods of wet weather & sunshine, or man-made as a result of scorching. Chlorothalonil (BRAVO) is very effective when used preventatively, helping to maintain green leaf area when used along with a triazole/strob mixture.

T3 Wheat

With ripening still approx 6 weeks away, the T3 treatment has to persist for all of this duration to prevent infection from a range of diseases such as SeptoriaNodorum (glume blotch), as well as Tritici, late season ear moulds and Fusarium. The cornerstone for the head spray fungicide is a strong triazole, giving strong curative activity to control any disease already on the plant as well as good persistence to prevent re-infection right up to ripening. Prothioconazole & epoxiconazole remain the most effective products to give ongoing Septoria protection as well as controlling fusariums and microdochiums on the ear. Prothioconazole (PROSARO) is the highest rated triazole for this range of diseases. The addition of a strobilurin is also essential to extend the persistence of the triazole and improve activity on Yellow Rust. Good grain fill is totally dependent on retaining green leaf area for as long as possible, and the addition of the strobilurin extends the retention of green leaf tissue.

Aphids in cereals

Aphids are now appearing in crops and as the grains begin to fill they feed at its base, drawing off the sugars that should be filling the grain if left unchecked.
Growers need to continue checking crops for aphid’s right up to milky ripe stage (GS73), and spray if present in numbers.

Grassland

Grassland herbicides use growth function to kill weeds, therefore peak growth periods should be used for herbicide application. There must be sufficient growth to allow herbicides to be effective and vegetive growth is the key time to apply, as the chemical then gets drawn down into the roots. Herbicides are less successful once plants have progressed to the reproductive stage and have thrown a stem or began to seed. Once weeds are beyond the ideal growth stage for spraying they should be mown or topped and allowed to regrow again, and a herbicide applied to the fresh young growth.
To optimise efficacy of any herbicide, recommended water volumes should be observed, even when it means more time spent spraying. It is important to note ragwort plants in their second year are now coming close to flower and should be sprayed immediately as flowering ragwort is poorly controlled. The routine herbicide treatments for this weed are full rate MCPA or 2, 4-D, and they are most active on growing rosettes with reduced activity as the stem starts to extend. They are not clover safe. You can use a mixture of both these products as Nufarm Lupo which allows an increased dose herbicide compared with either alone, with a consequent activity benefit. Stock must be kept of until the weeds have rotted away, which can take up to six weeks.

Grain Store Hygiene

Ensuring stores are clean and pest free is essential to prevent any problems after all the hard work of growing and harvesting the crop. Now is the time to make grain stores ready for the coming harvest. Pest problems in stored grain arise from within the store itself, so a good clean-out is essential to minimise the carry-over of grain beetles, weevils and mites. The store should be empty and thoroughly cleaned before any treatment is carried out, removing all traces of grain and dust that might harbor insects or mites. Apply using an applicator to spray all surfaces including underside of roof and floor, concentrating especially on areas where dust can collect – cracks, light fittings, around equipment etc. RELDAN can be applied up to one month before filling the store and has no with- holding period when applied to the fabric of the store.

Horticulture

Carrot willow aphid is now flying into crops and they carry several virus diseases that affect both carrots and parsnips. They may cause leaf distortion and stunting if they infest plants at the seedling stage. Crops should be checked for aphids and an aphicide such as APHOX used if present. Where couch grass is a problem in carrots ARAMO can be used and has annual meadow grass as a label weed.

All weed control should now be almost complete on spring cereal crops. There was certainly plenty of opportunity to catch up on spray programmes over the last couple of weeks. Crops are moving through the growth stages very quickly this week with the damper conditions. Some spring barley in parts of North Down are already at flag leaf and East Down have crops with awns appearing. Wild oats may be controlled now as long as a period of three weeks has occurred from the weed spray application. Axial and Adigor may be used on both spring barley and spring wheat up to flag leaf. It is certainly a season where growth regulator will be required in abundance. As most crops are now past 2nd node growth regulation products are limited to Cerone for barley up to first awns visible and Adjust and Cerone on to spring wheat up until flag leaf sheath opening. Fungicide application is priority now as rynchosporium is spread by rain splash. This disease has been present in low levels up until now with netblotch being the most dominant disease in spring barley. Whatever the fungicide choice for spring wheat it is critical to include something to cover mildew as most varieties have mildew present on them.

Winter Cereals

Protecting the top three leaves at T2 is critical to yield and profit – up to 80% of the yield is generated from these leaves. Foliar disease not controlled effectively at this time will hasten the senescence of these leaves during grain filling, and therefore affecting yield and grain quality. Yet there is little point in applying any input if it does not give a financial return. To get the best return on fungicides, applying them at the correct timing is critical. Trial work in UK & ROI has consistently shown even in a low disease pressure year, a well-timed application will give returns of 2-4 times their cost and in high pressure situations 5-6 times their cost. In winter barley this should be applied from the end of booting through to awns fully emerged, GS45-59, and be robust enough to protect the upper leaves and ear through to the end of the season. Awns also contribute to yield and it is important to keep them free of disease also.
For winter wheat the T2 should ideally be applied between mid flag leaf to mid-booting, GS38-45 along with the growth regulator. The T3 treatment is then applied post ear emergence to mid flowering, GS59-65, targeting ear diseases and prolonging control of foliar disease on the top two leaves, especially important in wetter seasons and on susceptible varieties.Sumi-alpha should be applied along with the fungicide.

Potatoes

Much of the potato crop this season has gone into cold soils and therefore drills are only warming up now. Both weeds and potatoes have been slow to emerge to date. Most weed control programmes are based on residual products ie products that are taken up through the soil, and are therefore very dependent on sufficient soil moisture to work effectively. Soil conditions are ideal therefore at the moment, moist enough on the tops of the drills to allow the herbicide be taken into the soil and taken up by the germinating weeds.
A huge amount of SAC work suggests that growers should spray before crop emergence to moist clod-free ridges. Holding off until crop emergence will set the potatoes back significantly reducing final canopy cover, and compromise weed control especially if weather delays the application further. The weeds are best treated pre or very early post emergent, especially important on the difficult weeds; fumitory, knotgrass, bindweed, annual meadow grass.
The key message is to apply the herbicide combination before crop emergence, therefore avoiding any check to the crop once emerged and maximising range of weeds controlled.
It is Tuesday today as I write this article and the steam is rising up from the road as I look outside. This certainly has been the first day since potato planting I could say there is a risk of blight. During the early canopy development phase, emergence to rosette products that have zoospore activity are the most effective 1st spray. RANMAN, SHIRLAN or TIZCA will control any zoospores that may be in the soil (either from ground-keepers or infected seed) and provide good protection of the new plant.

Grassland

With farms being short of grazing because of the cold conditions it is important to minimize the effects of encroaching perennial weeds. When targeting nuisance perennial weeds such as docks, nettles and thistles it is important to apply herbicides when the plants are actively growing and at the correct growth stage.
Most herbicide applications to silage ground occur prior to or just after first-cut. Depending on cutting date, the quality and quantity of silage taken will vary, placing greater importance on achieving the best second-cut possible.
Perennial weeds such as docks can significantly affect both the quantity and quality of grass harvested, so well-timed herbicide applications after first cut can reap rewards for the rest of the season and even into the next spring. This is likely to be particularly so this year with recent rainfall in helping to stimulate weed growth. To optimize results, wait for 2-3 weeks after cutting for docks to regrow to the rosette stage, and then apply DOXSTAR to actively growing plants. Doxstar has been developed to deliver the highest levels of dock control. The formulation and the presence of two actives; fluroxypyr and triclopyr, delivers a significantly higher level of control than straight fluroxypyr.

Good levels of weed control can also be achieved in grazing leys at this time of year. Where mixed weed populations are present, including docks, nettles and thistles, PASTOR is the most appropriate product to use. With the dry spring limiting grass growth, stock will have to graze closer to thistles leaving sheep vulnerable to orf. Getting rid of thistles in sheep pasture with THISTLEX significantly reduces the spread of orf while increasing grassland productivity.

FOREFRONT may be applied onto grazing ground giving excellent weed control with no effect on the grass. FOREFRONT contains Fluroxypyr and aminopyralid. As well as controlling docks it will control chickweed, buttercup, dandelion, nettle and thistle.
Treat weeds at the rosette stage, when they are actively growing. If stem extension is already occurring, use a mechanical topper first, and then treat regrowth when it reaches the correct stage.

The prolonged period of cold weather over recent weeks had restricted growth of all spring crops sown in late March. Whilst all germinated well, growth of most crops had been particularly slow. Rainfall has been adequate, enough to maintain good soil moisture ensuring even germination of crop and weeds, and not too much to cause any transient yellowing associated with plants struggling to take up nutrients in waterlogged soils.

The problem was very much the lack of heat, restricting nutrient availability and therefore growth and development. The pleasant rise in temperature this week has encouraged both weeds and crops to move rapidly. To date aphids have been discouraged from flying due to cool conditions but this will have changed this week with the sudden increase in temperature.

The well below average air temperatures up until now mean soil temperatures have also been well below average for the time of year. The Nitrogen mineralisation process in the soil where fertiliser nitrogen is converted to a form that can be taken up by the crop is a soil microbe process and therefore dependant on soil temperature. Hence colder soil has slowed the availability of nitrogen to the crop, and many other nutrients also, particularly manganese. Many crops are beginning to show nutrient deficiencies as a result.

The application of a broad-spectrum trace-element mix along with key macronutrients at this time is a very useful and beneficial way to supplement the plant’s nutrient requirements during periods of restricted availability, especially when coinciding with phases of rapid growth ie. during tillering and as stem extension begins. An application of a balanced and readily available source of macro & micronutrients that is not dependant on soil availability at this key time will minimise the adverse effects of restricted soil nutrient uptake.

Spring Cereals

To minimise the effects of competition on the crop and optimise the level of weed-control, the herbicide application should be carried out sooner rather than later, once all the weeds have emerged but are still small, and before they begin to compete with the crop for nutrients and light. Carrying out the weed control at the 2-4 leaf stage will lower rates of herbicide and give a much more effective result than delaying to coincide with the 1^st fungicide application.

Product choice depends on the weed type and size present and crop growth stage.

Broad leaved wise, Sulfonyl-urea (SU) herbicides will likely be the starting point, controlling a wide range of weeds and are very safe to the crop.

Where the range of BLWs present are limited to chickweed, redshank, fat hen, fumitory & day nettle, the hormone mixture products will work well without the need to tank-mix, but must be applied by GS31. Where the likes of field pansy, forget-me-not, speedwells & corn-marigold are also present however, sulphonyl-ureas products will improve control. Conditions over the last week have been ideal for hormone products with consistent day and night temperatures. Compitox, Minstrel and Oxytril are the most widely used tank mix partners with SU’s.

Grass weeds are commonplace this season especially on head rigs, HUSSAR is the only product now available to treat AMG in spring crops, controlling it up to the end of tillering. It also gives very useful suppression of wild oats that are emerged at the time of application (further plants are likely to emerge later). It also controls a range of BLW very similar to the other SU’s.

If clover is part of the mixture, a clover safe product must be used. TRIAD is a new clover-safe herbicide available for the first time last season. Whilst currently labelled for use in ‘Spring Barley undersown with IRG’ only, a new wider label is currently going through the approval process reading ‘Spring Barley undersown with grass, and grassland’. If seedling docks, thistles and buttercup are also problem weeds, SPRUCE must be added to the TRIAD to improve control of these also. SPRUCE is 2,4DB, a clover safe hormone type herbicide.

Winter Barley

Rhyncho is present in most crops at various levels depending on the disease control already applied. The cool and damp weather pattern over the last month has been ideal for this disease, and without a robust and properly timed fungicide application this disease will move rapidly up the plant onto the upper leaves, awns and heads. Mildew is also present at varying levels. Ramularia is also beginning to show, with newer varieties showing greater sensitivity to this late developing disease. It tends to show late in the season usually after booting, symptoms are very similar to manganese deficiency.

The SDHI chemistry now available have a good position at T2 on winter barley crops where they retain green leaf and are very active against Ramularia. However whilst Bixafen (Bayer) and xemium (BASF) have curative activity, triazoles are still essential to the core of the T2 fungicide mix, with prothio, epoxi and flusilazole being the most robust for Rhyncho, both preventative & curative The SDHI actives are more long lasting than other chemistry groups, providing enhanced disease control and extending the protection period by up to 3 weeks. They also give consistent increases in green leaf area in the field, delay senescence and improve drought tolerance, all components that build yield.

Bixafen, available in mixture with prothioconazole as SILTRA for barley is particularly strong on Rhyncho. Xemium is also very strong but its partner triazole in ADEXAR, epoxiconazole is not as strong as the Bayer triazole. BASF also have boscalid, another SDHI active available in mixture with epoxiconazole as CHORD. Whilst the boscalid is not as curative as xemium, CHORD is very strong on Rhyncho and also has excellent activity on Ramularia at T2. Isopyrazam (Syngenta), in mixture with cyprodinil as BONTIMA for barley is particularly strong on rusts. None are particularly strong on Mildew or Fusarium.

Chlorothalonil is still an option when used preventatively to improve Ramularia activity but only when an SDHI is not being used at T2. (It has no activity on any other barley diseases.) FIELDER is an ideal triazole partner, combining both TALIUS and chlorothalonil in the one pack to control both  Ramularia and Mildew Where the SDHI chemistry is not being used, strobs also have a very important role in the T2 fungicide programme in those crops with good potential, improving control of Brown Rust, Net Blotch & Rhyncho. With a different mode of activity to the triazoles, it is an excellent partner in resistance management.

Winter Wheat

Most crops have now moved through the stages of stem elongation.Septoria tritici is present in all crops at variable levels depending on T1 timing. Mildew is also present in all varieties depending on whether TALIUS has already been applied.

The flag leaf will be emerging in most crops within the next week or two, and this is the key time to apply the T2 treatment. Of all fungicide treatments, T2 gives the greatest response in terms of grain yield and quality, keeping the top three leaves clean and the ear as it emerges. For this reason the manufacturers are targeting their new SDHI chemistry at this timing when the big spend will give the greatest return. Trial work on both sides of the Irish Sea last year showed consistently higher yields when these products were applied at this time.

While not as curative as the triazoles, each manufacturer claims extended persistency against Septoria for their SDHI actives. Co-formulated with triazoles, they all show excellent Septoria activity as well as extended activity on rusts and in the absence of disease enhance green leaf retention (similar to strob activity), so boosting grain-fill. Whilst their disease performance is not enhanced by the addition of a strob or chlorothalonil at this timing, from a disease resistance management point of view chlorothalonil should continue to be added.

Epoxiconazole and prothioconazole remain the key triazoles for controlling Septoria. However the difficulty in controlling this disease should not be underestimated. Part of any pathogen’s survival mechanism is to change in response to outside influences that adversely affect its development, and the Septoria pathogen is continuously modifying itself in response to a fungicides’ mode of action, developing ways around it. Population strains of the Septoria pathogen continue to change. New genetic variants are more able to tolerate particular fungicides, becoming harder to kill with epoxi and prothio (Group 1 triazoles). However these same strains are easily controlled with certain older triazoles including tebuconazole and metconazole (Group 2 triazoles). Hence the rationale for the best performing triazole products in recent years to be co-form triazole mixtures. In PROSARO, Bayer have demonstrated over the last 3 years that the effect of two triazoles mixed together is greater than the sum of both when used separately, the tebuconazole improving the product performance on Septoria over straight prothioconazole. BASF have identified a similar effect with BRUTUS, a mixture of epoxiconazole and metconazole. This product consistently outperforms straight OPUS, gram for gram and produces results in the field similar to PROSARO.

The rising temperatures over the last week have been very welcome for all crops but unfortunately awns have begun to appear on winter barley with critical plant growth regulator missed. Mildew is present on almost all winter cereal crops and should be treated at T2 timing. In spring barley & spring wheat an early application of ADJUST increases root development and the numbers of surviving tillers which will improve crop establishment and yield. Because of the spring crops more rapid progression through the growth stages than the winter crop, the growth regulator must be applied very early to maximise the suppression of apical dominance and therefore divert nutrients and growth to promote secondary tiller development. Optimum timing for barley is from the 2nd expanded leaf stage to beginning of tillering, GS12 – 21 whilst in wheat the optimum timing is slightly later, 5 leaf to mid tillering, GS15-24. This treatment also gives a consistent straw shortening effect in wheat, but not in barley.
Leatherjacket numbers are considerably higher this year with widespread damage to grass swards particularly in the west of the Province. Damage is now becoming evident in some of the earlier drilled cereals. Feeding activity and therefore the likelihood of damage will increase as soils continue to warm. Crops most at risk are those drilled into old ley or dirty stubble, but monitor all emerging crops closely for signs of damage. The grubs will be quite easy to find in areas of poor emergence, when the soil is dug down to a depth of 4-5cm.

Spring Barley

To minimise the effects of competition on the crop and optimise the level of weed-control, the herbicide application should be carried out sooner rather than later, once all the weeds have emerged but are still small, and before they begin to compete with the crop for nutrients and light. Product choice depends on the weed type and size present and crop growth stage. Broad leaved wise, Sulfonyl-urea (SU) herbicides will likely be the starting point, controlling a wide range of weeds and are very safe to the crop. However they must always be tank-mixed with another BLW herbicide to control SU resistant weeds (chickweed) and those weeds not controlled by the SU’s (cleavers, fumitory and fat-hen). Ideal partners are Compitox,Oxytril Cm and Spitfire. Each of these partner options are very tank mixable, and other products such as ADJUST and MAXMAN can also be safely added.
Where the range of BLWs present are limited to chickweed, redshank, fat hen, fumitory & day nettle, the hormone mixture products will work well without the need to tank-mix, but must be applied by GS31. Where the likes of field pansy, forget-me-not, speedwells & corn-marigold are also present however, sulphonyl-ureas products will improve control. Spring barley, spring wheat and spring oats undersown with grass and clover should be treated with TRIAD and where clover is not important MIRCAM PLUS should be applied. If seedling docks, thistles and buttercup are also problem weeds, SPRUCE must be added to the TRIAD to improve control of these also. SPRUCE is 2,4DB, a clover safe hormone type herbicide.

Winter Barley

All winter barley crops have now received their T1 fungicide, with the T2 planned for the coming weeks. Prothioconazole in (MOBIUS or SILTRA) or epoxiconazole in (MANTRA or ADEXAR) at this critical timing will give maximum benefit over straight triazole products. Mildew levels are extremely high and thereforeTALIUS should be added.

Winter Wheat

Like the winter barley, the mild winter means Septoria and Mildew levels are higher than seen at the same time in recent years. Yellow Rust has also been found in some earlier sown crops and the threat will remain high. Robigus and Einstein have both broken down to new races of this disease and are more susceptible than ever. Like the barley, the T2 application should now be planned as recently applied fertiliser coupled with warmer temperatures will push crops through the growth stages very quickly.

Potatoes

With planting progressing well to date, this year’s crop is going in in almost perfect conditions right across the Province. Drills are moist and with this week’s increased temperatures rapid emergence of both crop and weeds will occur. Therefore growers should be planning weed control now, taking good advantage from the moist soil conditions. Most weed control programmes are based on residual products ie products that are taken up through the soil, and are therefore very dependent on sufficient soil moisture to work effectively. Soil conditions are ideal therefore at the moment, moist enough on the tops of the drills to allow the herbicide be taken into the soil and taken up by the germinating weeds. Contact products such as RETRO,ROUNDUP and TITUS may be applied. All require the inclusion of a residual partner to maintain clean drills up to the time of the crop canopy closing the drills. Residual products are DEFY, SENCOREX, AFALON and GAMIT.
All potato herbicides carry timing restrictions and some namely SENCOREX have varietal restrictions and it is therefore important to seek advice on the best product choice.
SHOGUN has a full recommendation for scutch control on ware potatoes. It will also give excellent control of perennial ryegrass, wild oats and volunteer cereals. If the crop is under drought or temperature stress when sprayed, transient yellowing may occur. For this reason its use is not approved on seed crops since these symptoms could be confused with viral disease.
Grass and weeds have been under stress up to now and where silage is still some weeks away there is an opportunity to apply herbicide.

This has certainly been a very changeable week with wintery showers and night frosts. Many crops are under stress and care should be taken not to rush out and spray these where timing is not crucial. Manganese deficiency is now commonplace in many crops, symptoms showing more in Continuous cereal ground and ground recently limed. Symptoms begin with small pale green speckles appearing throughout the leaf and these will progress to turn brown unless treated.
Copper deficiency often accompanies Mn deficiency – its symptoms are complete browning of the leaf tip especially the youngest leaves, and apparent wilting of the plant. Treatment will be most effective if treated as soon as symptoms are seen.

SPITFIRE is now in its second season, it contains two active ingredients, a high loading of the sulfonyl-urea (SU) florasulam, and fluroxypyr. It has a very wide spectrum of weeds controlled including chickweed, cleavers, black bindweed, charlock, knotgrass, mayweeds and volunteer rape, and an equally wide window for application in all cereal crops. It can be used from 3-leaf of the crop GS13 right up to GS45 in winter wheat and winter barley; up to GS39 in spring wheat and barley; and up to GS31 in winter and spring oats, winter rye and triticale. Wild oats will continue to emerge in later drilled winter crops for another few weeks yet, so delay application until certain that all have emerged. To avoid crop damage, do not spray any crop under stress. Note that performance of some wild oat/brome herbicides can be adversely affected by other herbicides used on the crop. To avoid these antagonisms, a minimum time interval must elapse between application of the BLW herbicide application and this application.

Disease Control

The new fungicides containing an SDHI (Succinate Dehydrogenase Inhibitors) component add very cost effective yield benefits to both wheat and barley. Bixafen (Bayer), boscalid (BASF) and isopyrazam (Syngenta) are longer lasting than other chemistry groups, providing enhanced disease control and extending the duration of protection by up to 2 weeks compared to triazoles. This season sees the launch of another new SDHI molecule from BASF, xemium. In contrast to the other SDHI’s xemium appears to exhibit very good curative as well as preventative activity. Because this chemistry is considered to be at high risk to fungicide resistance, so they must only be used in mixtures with triazoles.
All of the SDHI’s give excellent activity on Rusts and Net Blotch. Bixafen, available in mixture with prothioconazole as AVIATOR for wheat and SILTRA for barley is particularly strong on Septoria and Rhyncho. Boscalid is available in mixture with epoxiconazole as CHORD and approved for both wheat and barley. As well as being very strong on Septoria and Rhyncho, it is the strongest molecule on Eyespot and therefore most suited to T1. It is also very strong on Ramularia in barley at T2. Isopyrazam, in mixture with cyprodinil as BONTIMA for barley and with epoxiconazole as SEGURIS for wheat is particularly strong on rusts. None are particularly strong on Mildew or Fusarium.
Xemium will be available in co-formulation with epoxiconazole, marketed as ADEXAR. As well as being one of the strongest performers against Septoria, because of its curative activity it is also the strongest product when timings have been stretched and therefore kickback is required.

Potatoes

Maincrop potatoes are currently being planted into ideal soil conditions right across the province. There are two types of herbicidal activity;
Contact herbicides which are those that must come into direct contact with the leaf of the target weed and will control all weeds that are emerged at the time of application – known as post emergent activity (post-em) and residual herbicides which move into the soil and prevent germination of the target weed before it emerges – known as pre-em
have only the one mode of activity; i.e. a contact will have no effect on weeds not yet emerged, while most residuals will not control weeds already emerged. In addition the residuals need sufficient soil moisture to work properly and in dry conditions residuals will not perform well.
Shogun has a full recommendation for scutch control on ware potatoes. It will also give excellent control of perennial ryegrass, wild oats and volunteer cereals. If the crop is under drought or temperature stress when sprayed, transient yellowing may occur. For this reason its use is not approved on seed crops since these symptoms could be confused with viral disease.

Grassland

Weed infestations can impact significantly on the yield and quality of grass for both grazing and cutting with trial work performed over the last two years by Dow Agroscience producing some shocking statistics. To put into perspective some of the figures, control of docks can give an average yield increase of 2.66t of DM/HA, enough grass for a cow to produce 5470 litres of milk. At 28p a litre this converts to £1531.00.Farmers will almost always apply fertilizer to grass swards because they can see the benefits but if I was to tell you that 3 bags of CAN could produce 320kg grass DM/HA which could produce 706 litres of milk at a value of £197.00 compared to dock control producing over 2000kg grass DM/HA which could produce 4452 litres of milk at a value of £1246.00.Which gives the better return?
It is important to allow one days growth for each 2-3 units of nitrogen between application and cutting to achieve good quality feed. 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. 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. 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 ,Mircam Plus 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.Triclopyr has a much wider weed spectrum and greater translocation than straight fluroxypyr and therefore there is greater efficacy and longevity achieved by mixing these two actives especially on docks. Forefront may be applied onto grazing ground giving excellent weed control with no effect on the grass. Forefront contains Fluroxypyr and aminopyralid. 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.

The excellent weather conditions experienced over last weekend and into this week have allowed Land to dry out well and spring fieldwork is progressing well. Growth has been good this week and crops have greened up well where fertilizer has been applied. Both grass weeds and broad leaved weeds are appearing in crops which did not receive an autumn herbicide. Wheat crops are still showing low levels of disease whilst most winter barley crops have a fair bit of foliar disease on older leaves. Potato planting has begun in some parts of the province and early carrots have also been sown. Many grassland farmers were keen to spray swards for chickweed and docks but it is too soon yet as night frosts have been occurring and weeds have become hardy hence will not take in the chemical particularly well.

Cereals

Much of the later drilled winter cereal crop did not receive a residual herbicide. As temperatures rise clods will be broken down on both treated and untreated crops requiring a herbicide treatment. Those wheat crops not treated in the autumn can be treated with OTHELLO and BIOPOWER up to GS32 of the crop. Applications should be made when temperatures are good and both the crop and weeds are actively growing. OTHELLO will give good control on chickweed, pansy, speedwells, charlock, groundsel and most importantly annual meadow grass. SPITFIRE is a new herbicide from Dow containing two active ingredients, a high loading of the sulfonyl-urea (SU) florasulam, and fluroxypyr. It has a very wide spectrum of weeds controlled including chickweed, cleavers, black bindweed, charlock, knotgrass, mayweeds and volunteer rape, and an equally wide window for application in all cereal crops. It can be used from 3-leaf of the crop GS13 right up to GS45 in winter wheat and winter barley; up to GS39 in spring wheat and barley; and up to GS31 in winter and spring oats, winter rye and triticale. Wild oats will continue to emerge in later drilled winter crops for another few weeks yet, so delay application until certain that all have emerged. To avoid crop damage, do not spray any crop under stress. Note that performance of some wild oat/brome herbicides can be adversely affected by other herbicides used on the crop. To avoid these antagonisms, a minimum time interval must elapse between application of the BLW herbicide application and this application. ALLY MAX and SPITFIRE should be applied onto any winter barley crops not yet sprayed but this will not control any grass present.

Manganese deficiency is now commonplace in many crops, symptoms showing as growth gathers pace. Continuous cereal ground and ground recently limed is most prone to deficiency.  Symptoms begin with small pale green speckles appearing throughout the leaf and these will progress to turn brown unless treated.

Copper deficiency often accompanies Mn deficiency – its symptoms are complete browning of the leaf tip especially the youngest leaves, and apparent wilting of the plant. Treatment will be most effective if treated as soon as symptoms are seen.

Disease Control

In our climate maximising yield means controlling disease effectively. Getting timings right is absolutely essential; ‘fire-brigade’ control of disease is more costly and a lot less effective than well timed preventative control.  Except in very low disease pressure conditions, it is a false economy to skimp on disease control and get away with it – all independent work shows that increasing fungicide doses does also increase yield.

This season sees the launch of the new BASF fungicide ADEXAR which is a mixture of xemium technology and epoxiconazole. ADEXAR is very curative and has acropetal mobility within the leaf area. It is labeled for both wheat and barley. This joins a number of newly approved cereal fungicides containing a new family of chemistry known as SDHI’s.

Preparing For Spring Crops

The focus over the last couple of weeks has been on preparing ground for spring crops. Land intended for spring cereals should be sprayed off with glyphosate as ground conditions allow. Roundup Energy is still the best value for money in the glyphosate market with all its additional benefits over generics. Roundup Energy has faster uptake and greater consistency in a wider range of weather conditions. It is important to remember when comparing glyphosate prices the amount of active it contains, Roundup energy contains 450gm/l compared to 360gm/l in most other glyphosate.

The increase in temperature over the last week will encourage pests such as wireworm, slugs and leatherjackets to resume feeding and should be closely monitored. Surveys carried out recently show leatherjacket numbers are significantly higher than spring 2011.Pre ploughing treatments with Dursban or Cyren are more effective than those applied once any damage is under way in the spring-sown crop.

It is essential to soil test prior to planting any crop, whilst it may seem expensive it is money well spent.

Winter Barley & Winter Wheat Growth Regulation

There are two types of lodging; stem-base lodging and brackling. Stem-base lodging is where the plant folds over at the soil surface as a result of poor anchorage in the soil, and is caused by poor root ball development, more likely when the seedling develops in wet soils that limit root development. Brackling is where the stem folds over part way up the plant, and occurs as a result of an inherent weakness of the variety, very dense canopies, and bursts of rapid growth.

Whilst CHLORMEQUAT (3C) will reduce the likelihood of brackling, it will have no effect on root growth; ADJUST on the other hand is active on both types of lodging when applied at the correct timing.

An application of the growth regulator often goes on with a T1 fungicide application sometime around 1st-2nd node, GS31-32. At this timing it primarily stiffens the stem by shortening the internodes, so reducing the likelihood of brackling. However when applied before the end of tillering, GS29, the growth regulator increases root growth also and so reduces stem-base lodging.

ADJUST will work right down to 1°C and is safe to the crop, particularly when applied in tank-mix with other pesticides. When applied early it also has a very significant effect on increasing tiller survival so improving yield potential. It is an excellent aid to managing more backward crops when applied at mid-tillering, GS22-24, helping these crops thicken out.