Wendy Fearon

Growth is not what we would expect for the middle of April, and it is important to note that stress in whichever form will affect nitrogen utilisation. Nevertheless top dressings are kicking in and crops are starting to come away. The poor economics across the agri-sector coupled with the persistent bad weather conditions have left a very depressive mood amongst many of the farmers I have been speaking to in recent weeks.

Winter Barley GS30 – GS31

All crops have completed tillering, with the most forward fields past 1^st node, GS31. Most are looking well considering the wet conditions over the winter. There are good plant counts and tiller numbers, but the mild winter means disease is already well established on these young plants with Rhyncho, mildew and net blotch showing in all. Rhyncho remains the most damaging disease of barley, seriously damaging yield potential if not controlled quickly and effectively.

Winter Wheat GS22 – GS30

Growth stages vary widely depending on drilling date but most are at various stages of tillering. Most have good plant numbers but some fields have suffered from waterlogging, slug, leatherjacket and rabbit damage. Septoria is established in all crops but particularly so in earlier drilled fields.

Disease Control

Rhynchosporium and Septoria are the two most damaging cereal diseases in NI. Both have always been more effectively controlled protectantly, but in previous times where the curative properties of the azoles were able to rescue a bad situation later, particularly in wheat this is no longer the case. Growers must now change their approach, looking to keep ahead of both diseases by starting earlier than before and maximising the protectant activity of the chemistry available. .

Timing of fungicide applications and rates used are every bit as critical as product choice to achieve the maximum potential response. To ensure the main disease programme persists right through to ripening, it is adviseable that all crops should have by now have received a T0 fungicide. Farmers should not apply their main T1 fungicide application before about the middle of April, with the T2 and T3 applications following at 4-5week intervals, ie mid-May and mid-June. This T1 timing should coincide with the beginning of stem extension between 1^st and 2^nd node, GS31-32.

Holding the T1 timing to GS31-32 should ensure T2 in barley and T2 & T3 in wheat be optimally timed to avoid extended gaps, maintaining persistency right up to and during senescence. Where a crop has not received a T0 treatment product rates at T1 will need to be increased to take account of this.

Since their introduction, fungicide programmes containing SDHIs, or succinate dehydrogenase inhibitors have consistently out-performed triazole only programmes. These are the newest family of chemistry available to cereal growers and now considered the mainstay of disease control programmes. They work by inhibiting fungal respiration and are more effective at controlling a range of diseases than older products, particularly as the performance of triazoles continue to decline each year. However SDHIs only have this single mode of action and therefore resistance and the associated breakdown in control is a very real threat to these products. To try and prevent resistance building up against the SDHIs, they must be used only twice in a season and in conjunction with another fungicide, such as a triazole, with a different mode of action. Of the SDHI products available, penthiopyrad (in AYLORA/CIELEX) has proven to be the most effective performer on both Septoria and Ryncho. Boscalid (CHORD) remains the strongest active available to control Eyespot and therefore a very good option for use on wheat at T1.CONCORDE containing isopyrazam and cyprodinil will be widely used as T1 on barley this season. This is an SDHI mixture proving to be very strong on both eyespot and ryncho.The T1 treatment in oats should be applied at the same time as the growth regulator. Whilst traditionally a single fungicide program was often used on this crop, a 2-spray program consistently outperforms a single spray in terms of yield, bushel-weight and profitability.CAPALO is the strongest T1 treatment available in oats, giving excellent curative activity on Crown Rust and Mildew when applied at 1^st–2^nd node (GS31-32), and is very persistent keeping new growth clean right up to full flag leaf (GS39) when the T2 is applied.

Weed control

Many crops have received an autumn herbicide but for those still to be treated, control of Annual Meadow Grass (AMG) is the most pressing issue. OTHELLO is an excellent option for AMG in wheat, however there is no similar late option for barley. Note that OTHELLO will only control AMG that has already emerged; unlike the autumn products it has no pre-emergent activity. Where the AMG has been controlled in the autumn but for example chickweed, cleavers or groundsel is likely to be a problem, SPITFIRE is an excellent stand-alone broad spectrum herbicide controlling these and most other emerged BLW. It also works best when the weeds are growing actively and has post em activity only, therefore delay use until all cleavers have germinated and temperatures have risen to encourage growth. SPITFIRE is also an excellent tank-mix partner with OTHELLO.

Growth regulation

When applied before 1^st node, GS31, application of certain chlormequat growth regulators can significantly increase tiller numbers. Chlormequat works by suppressing apical dominance, ie main stem development. In doing so it diverts the plant’s resources into producing and supporting more tillers. Particularly in wheat but in barley also, more tillers will go a long way towards compensating for low plant counts, ultimately increasing yield.

Correct timing is critical to maximise this effect. The earlier it is applied during tillering the greater the tiller effect, but note early application to increase tiller numbers will also reduce its effect on lodging. Application of a chlormequat based growth regulator often goes on with a T1 fungicide application sometime around 1^st-2^nd node, GS31-32. At this timing it is too late to affect tiller numbers and survival but will maximise the stem stiffening effect.

Early application will also increase root growth and so reduce stem-base lodging. 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. All winter crops have rooted very shallow this season as a result of the persistently wet conditions and therefore stem-base lodging is likely to be a significant problem later this season.

SELON can be tank-mixed with the herbicide and where the crop has begun to tiller, should be applied now.

Nutrient Deficiency

A combination of waterlogged soils, plants already suffering from restricted nutrient uptake and plants now trying to grow is showing up Mn deficiency in many barley crops. 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.

As soon as the ground allows, Mn deficiency should be addressed and applied as soon possible along with the SELON application to increase tiller numbers.

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 immediately symptoms are seen.

With air quality significantly improving over the last two decades, the most important source of sulphur to the soil coming from the pollutant gas sulphur dioxide has also reduced significantly. Whilst its deficiency is now being recognised and corrected on grassland through the application of high sulphur compound fertilisers, its impact in cereal crops in NI has by and large been misidentified or overlooked. After nitrogen, phosphate and potash, sulphur is the next most important element required by all crops, used to make essential sulphur containing amino acids and proteins in all plants. Soil sulphur is easily leached especially from light to medium soils, making shallow-rooting plants particularly vulnerable to deficiency. Deficiency causes paling in the cereal plant, caused by a reduction in chlorophyll production and even in the absence of any symptoms, decreased efficiency of nitrogen utilisation. Whilst often mistaken for lack of nitrogen, sulphur is not very mobile within the crop and therefore deficiency is most pronounced on the younger leaves; the opposite to nitrogen deficiency which affects the oldest leaves first. Crops of both wheat and barley with high yield potential are particularly responsive to one to two applications of foliar sulphur at the timings of rapid growth.

Welcome to the first crop crack of the season. As I write this article on this fine spring morning I have momentarily forgotten the difficult and challenging times with regards to weather and markets we have experienced over recent months. Wind and rain have been the main features of the winter with most fields still remaining quite wet. Despite this, the mild conditions have meant crops and grass continue to grow. Crops that were early sown are surviving well apart from parts of fields where the water has remained on the surface for an extended period. Disease is certainly present in crops in varying levels. As ground conditions improve spring fieldwork can commence and fertiliser and spray applications can get underway.

Autumn 2015 was again kind to us, allowing much of the winter barley and some winter wheat to receive a herbicide treatment during October and November. Mixtures of CRYSTAL and SEMPRA were widely used and by and large, performance has been excellent.

Control of Annual Meadow Grass (AMG) is the first priority in all crops if not already done with an autumn treatment. OTHELLO is an excellent contact solution for AMG in wheat in the spring, however there is no similar contact option for barley. None of the autumn products will control AMG beyond the mid tillering stage, yet they are the only AMG options for barley. Note that the actives in OTHELLO that control AMG (iodosulfuron and mesosulfuron) will only control AMG that has already emerged; unlike the autumn actives these are not residual and have no pre-emergent activity. In addition they require the weeds to be growing actively so delay its use until all grasses have emerged and temperatures have risen to allow growth to have resumed.

OTHELLO will also control a wide range of pre or early post emerged broad leaved weeds, but where these weeds have size then a contact product needs to be added to ensure larger overwintered BLW are controlled effectively. The cheapest option is DUPLOSAN, improving control of chickweed, fumitory and cleavers, but is temperature sensitive, therefore needs a milder spell to work properly.

Where the AMG has been controlled in the autumn but for example over-wintered chickweed, cleavers or groundsel are problems weeds now, SPITFIRE is a more effective option controlling these and most other emerged BLW. It also works best when the weeds are growing actively and has post em activity only, therefore delay use until all cleavershave germinated and temperatures have risen to encourage growth.

Brome grass and wild oats

Brome grass infestations are becoming more prevalent right across the province. Last season in particular saw a significant increase in the numbers of infested fields, with rye brome appearing in quite a number of winter barley crops where it was not previously present.

Effective control can only be achieved using a combination of cultural and chemical control methods. Cultural control methods (break crops, stale seedbeds).Chemical control then is a sequenced approach of an autumn treatment followed up with a spring treatment. CRYSTAL at 4lt/ha in the autumn was the first part, and should have been applied to wheat and barley. The follow-up then in the spring is BROADWAY STAR but note this product can only be used on wheat. There is no follow-up brome product available for barley and therefore in a severe infestation situation, only wheat allows effective control.

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 applications of the various herbicides.

The need T0 treatment?

Rhynchosporium and Septoria are the two most damaging cereal diseases in NI. Both have always been more effectively controlled protectantly, but in previous times where the curative properties of the azoles were able to rescue a bad situation later, particularly in wheat this is no longer the case. Growers must now change their approach, looking to keep ahead of both diseases by starting earlier than before and maximising the protectant activity of the chemistry available then right through to crop senescence.

In barley the lower leaves contribute more to grain fill than the upper leaves. Therefore, particularly in a year like this where crop was drilled early last autumn, plants are forward and disease is already present, so a relatively cheap T0 applied now will reduce the level of inoculum present keeping the newly emerging leaves clean and allow the T1 be better timed and protectant focused. Most of the azoles still have good curative activity on Rhyncho and the addition of morpholine will strengthen this as well as control Mildew.

With virtually no curative activity available in wheat, maximising protectant activity is paramount. Multiple modes of action in the tank is also essential, ensuring control of all strains of Septoria. Whilst only ever having had protectant activity, chlorothalonil has multiple modes of activity and as a result still controls all strains of Septoria including those now resistant to the various azoles. This makes it an essential partner at all timings, supporting the azole and SDHI chemistry to control all strains and help slow the build-up of resistance. Application of a T0 introduces Septoria and rust protection early, allowing the T1 be better timed and still targeted at protectant activity. For most situations a triazole/chlorothalonil mix will work well.

Growth regulation – managing thin crops

When applied before 1^st node, GS31, application of certain chlormequat growth regulators can significantly increase tiller numbers. Chlormequat works by suppressing apical dominance, ie main stem development. In doing so it diverts the plant’s resources into producing and supporting more tillers. Particularly in wheat but in barley also, more tillers will go a long way towards compensating for low plant counts, ultimately increasing yield.

Correct timing is critical to maximise this effect. The earlier it is applied during tillering the greater the tiller effect, but note early application to increase tiller numbers will also reduce its effect on lodging. Application of a chlormequat based growth regulator often goes on with a T1 fungicide application sometime around 1^st-2^nd node, GS31-32. At this timing it is too late to affect tiller numbers and survival but will maximise the stem stiffening effect.

Early application will also increase root growth and so reduce stem-base lodging. 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. All winter crops have rooted very shallow this season as a result of the persistently wet conditions and therefore stem-base lodging is likely to be a significant problem later this season.

Only chlormequat works by suppressing apical dominance, but the active itself does not work effectively at temperatures below 8°C. ADJUST, a more consistent chlormequat formulation was widely used here in NI for some years, subsequently replaced a number of seasons ago with a newer formulation known as SELON. The manufacturer Taminco further developed the formulation and adjuvant partner to enhance the uptake in marginal conditions and therefore improve the reliability of performance, consistently working right down to 1°C. The new adjuvant mix also works as a crop safener, particularly when applied in tank-mixes with other pesticides. The rates of use, label timings and tank-mix flexibility for SELON are identical to ADJUST.

Manganese deficiency in winter barley

A combination of waterlogged soils, plants already suffering from restricted nutrient uptake and plants trying to grow will lead to Mn deficiency appearing in many barley crops. 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.

As soon as the ground allows, Mn deficiency should be addressed as soon as possible along with the SELON application to increase tiller numbers.

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 immediately symptoms are seen.

Sulphur deficiency in winter wheat and winter barley

With air quality significantly improving over the last two decades, the most important source of sulphur to the soil coming from the pollutant gas sulphur dioxide has also reduced significantly. Its deficiency is now being recognised and corrected on grassland through the application of high sulphur compound fertilisers, however in cereal crops its impact in NI has by and large been not been recognised or misidentified. After nitrogen, phosphate and potash, sulphur is the next most important element required by all crops, used to make essential sulphur containing amino acids and proteins in all plants. Deficiency causes paling in the cereal plant, caused by a reduction in chlorophyll production and decreased uptake and efficiency of nitrogen utilisation. Though often mistaken for lack of nitrogen, sulphur is not very mobile within the crop and therefore deficiency is most pronounced on the younger leaves; the opposite to nitrogen deficiency which affects the oldest leaves first.

Crops of both wheat and barley with high yield potential are particularly responsive to one to two applications of foliar sulphur at the timings of rapid growth.

Winter Wheat

All T3 fungicide applications onto winter wheat should now be planned for application over the next couple of weeks. Winter wheat crops have moved at exceptional pace during the dry warm period over the last couple of weeks. The cornerstone for the T3 head spray fungicide is a strong triazole that as well as being effective on Septoria is also effective on Fusarium.  Prothioconazole & epoxiconazole remain the most effective products to give ongoing Septoria protection. Tebuconazole and metconazole are very strong triazoles for Fusarium and an important contributor at this time. The addition of a strobilurin is also essential to maximise the persistence of the triazole and strengthen 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. Pyraclostrobin (COMET) is still the highest rated strob for use in wheat being the strongest performer on Yellow rust and the late ear disease. I have seen a lot of physiological tipping on winter wheat and there are a lot of theories as to what may have caused this but most noticeably it seems to be specific to certain varieties. Mildew has been present on most cereal crops this season where the variety has low resistance a mildewicide must be included in the fungicide program.

Spring Barley

It is fair to say that most spring crops have made a remarkable recovery over the last couple of weeks. All weed control should now have been carried out on spring barley crops and the T1 fungicide application must be planned as rhyncho is now showing on varieties Concerto and Waggon. The two most dominant diseases in our climate are powdery mildew and rhynchosporium with ramularia becoming an increasing problem over recent years. Ramularia can be difficult to identify but unlike most other physiological leaf spots which are only visible on the upper side of the leaf ramularia is easily seen both on the upper and lower surface of the leaf and the longitudinal edges of the brown lesions remain enclosed by the leaf ridges. 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.

All weed and disease control should now be complete on both spring wheat and oats.

Grassland

Attention must now be given to those grass fields which were not sprayed prior to first cut. 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. Forefront is the most effective herbicide on ragwort.

Stock must be kept off until the weeds have rotted away, which can take up to six weeks.

The prolonged period of cold wet 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. Most crops appear to have recovered from the transient yellowing associated with plants struggling to take up nutrients in waterlogged soils this past week.

The problem was very much the lack of heat, restricting nutrient availability and therefore growth and development. The slight rise in temperature this week has encouraged both weeds and crops to move steadily. To date aphids have been discouraged from flying due to cool conditions and aphicides at present may not be required. It is important to remember the work of the beneficial insects on crops.

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.

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. For winter wheat the T2 should ideally be applied between mid-flag leaf to mid-booting, GS38-45 along with the growth regulator. Most winter barley crops are looking exceptionally clean and should  have good yield potential if the weather works in our favour . I think we are well overdue a spell of decent weather, although predicted prices would not excite any of us!

Potatoes

The protracted planting this spring has meant most potato crops have yet to receive weed control. This task must take priority as to delay until after crop emergence will set the crop back even further in an already late season. Conditions have been ideal for the use of residual products (Afalon,Linurex,Sencorex).Where broad –leaved weed control has yet to be completed and the crop has passed the latest timing for Sencorex a reduced rate of Sencorex tank-mixed with Titus will provide a wider weed spectrum of weed control than Titus used alone and can be used on emerged crops up to 25cm high where the label allows .Scutch, other grasses or volunteer cereals are not controlled by the Titus/Sencorex mix. Where these weeds become a problem in coming weeks the graminicide Shogun can be applied. Shogun can cause transient yellowing and is therefore not approved for use on seed crops.

As canopies close, the soil surface will tend to remain damper, encouraging slugs. Timing is critical for effective control, just before the crop meets across the rows. Take advantage of any rainfall by applying pellets just afterwards, as this rain will encourage slugs up onto the soil surface. Potato varieties particularly susceptible to slug damage include Maris Piper ,Desiree and Kerrs Pinks.

Blight fungicides move through the plant in three different ways contact, translaminar and systemic.Dithane,Ranman Top, Shirlan and Tizca are all contact fungicides. These Products protect only the outer surface of the leaf onto which they are deposited.Translaminar products such as Curzate M, Invader, Resplend and Revus move into the leaf and redistribute throughout the leaf tissue as it increases in size whilst systemic products such as Consento and infinito move in through the leaf surface and upwards into the new growth protecting this from infection also. Products that have zoospore activity are the most effective 1^st spray, applied at the rosette stage prior to rapid haulm growth. Shirlan or Tizca will control any zoospores that may be in the soil and provide good protection of the new plant. During the main canopy development phase with the considerable amount of new growth 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 drilled crops, at a time when the level of inoculum in the air is progressively increasing. 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 adhesions onto the leaf immediately post application and over the following days should rainfall levels remain high. The way the blight product is applied is as important as the product choice. Make sure nozzle type used is correct to ensure sprayer pressure; droplet size and water applied is as directed on the label. Inspect and calibrate nozzles regularly to maintain performance. Never use any blight product at reduced rates. Do not spray when the leaves are wet as this will significantly increase the likelihood of runoff

The mixed weather and below average temperatures have certainly made things difficult for both arable and grassland farmers recently. We have almost accepted there is no such thing as the norm anymore. It has been very frustrating for farmers trying to grab every available opportunity to spray crop as ground underfoot has become very soft. Conditions however have been ideal for weed control onto potatoes and veg as residual herbicides require moisture to work effectively.

SPRING CEREALS

The above average rainfall over winter has depleted many soils and it is essential to replace essential nutrients. Spring barley crops grown on low PH soils with a low P index seem to be struggling most this season. This must be rectified with lime and Phosphate fertilizer in accordance with soil analysis.

An application of a balanced and rapidly available source of macro & micronutrients at this key time will minimise the adverse effects of restricted soil nutrient uptake. CEREAL HIGH N supplies 3.7%Mn, 1.5%Mg, 1.8%Cu, and 0.6% Zn in the most rapidly available form to the plant through the leaf and also supplies high levels of Nitrogen and Sulphur.Potash deficiency is also showing up in many spring barley crops with pale green yellow tips being the first symptom.Deficency is most likely on light sandy soils or in crops following intensive grassland. Manganese deficiency is also appearing on crops especially those in a continuous cereal regime or where lime has been applied recently. A foliar application may be applied along with the weed control.

To minimise the effects of competition on the crop and optimise the level of weed-control, herbicide application should be carried out at the earliest opportunity, once all the weeds have emerged but are still small, and before they begin to compete with the crop for nutrients and light. With low soil temperatures since drilling, weeds are not coming through as rapidly as expected but chickweed is beginning to choke out young plants and must be sprayed as soon as possible.

Product choice will depend on the weed type and size present and the crop growth stage. Broad leaved wise, Sulfonyl-urea (SU) herbicides will likely be the starting point, controlling a wide range of weeds and very safe to the crop. ALLY MAX covers a wide spectrum of BLW with the max formulation giving improved control of polygonums & other BLW over the old ALLY formulation. HARMONY SX controls a wide range of BLW at sizes larger than any other SU. 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& fat-hen). Ideal partners are COMPITOX controlling (chickweed, fat-hen, fumitory), and SPITFIRE /MINSTREL for chickweed and cleavers. HUSSAR may be applied to spring wheat and spring barley to help control annual meadow grass.

Where the range of BLWs present are limited to chickweed, redshank, fat hen, fumitory & day nettle, the hormone mixture products, such as Mircam Ultra, 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, sulphonyl-urea products will improve control.  AXIAL gives excellent control of wild and tame oats in spring barley and spring wheat and has an excellent window of opportunity.   Application should be held off until at least 6 weeks after drilling to ensure all wild oats have germinated. It can then be applied up to full flag-leaf of the crop and full flag leaf of the wild oatGS39, allowing a minimum of 21 days to have elapsed after application of the BLW herbicide.  The wetter ADIGOR must be used in all situations along with the AXIAL.

WINTER WHEAT

Most crops are now at flag leaf with Septoria tritici present in most crops at variable levels depending on T1 timing but with recent weather expect levels to rise if fungicide rates and timings are not correct. Mildew is present on almost all winter wheat varieties and a morpholine based product should be applied to clean up the crop. The inclusion of Talius in the program will give very good persistent control of mildew. Of all fungicide treatments, T2 has the greatest impact and response in terms of grain yield and quality, keeping the top three leaves clean and the ear as it emerges. The dose rate applied must be sufficiently robust to ensure long term protection of the flag leaf plus eradicate disease already present on the lower two leaves that also contribute to yield. Epoxiconazole & metconazole in mixture(BRUTUS) will form the key part of the T2 fungicide onto winter wheat.  SDHIs are now regarded as essential partners to maximise the yield of all crops with any reasonable potential, with the most responsive timing for the newest SDHI molecules being at T2. Products such as PEXAN or AYLORA/PROSARO mixtures are ideal for use at the T2 timing. Growth regulator (CERONE)must also be applied at this time where required.

The last fortnight has offered very little spray opportunity but every available chance must be taken to ensure correct spray timings. Most winter barley crops are now at flagleaf fully out to awns just visible. Because of the very poor growing conditions this spring, nodes and crop height is not a good indicator alone of the plant growth stage. Growth stages in cereals are hugely influenced by day length. The longer days are driving ear development, and with it ear emergence.

In winter wheat the weakest part of the stem tends to be the lowest internodes and therefore growth regulation at this time maximises strengthening, in barley it is the higher internodes that are weakest. In winter barley the SELON growth regulator applied some weeks ago enhances root anchorage and tiller survival, but has little effect on controlling stem lodging. It is during the later stem extension stages and early flag leaf emergence that the maximum straw strengthening effect will be achieved. When the application is delayed beyond this timing efficacy drops off rapidly, as with each passing day the stem has already added on further length. In any event it is essential the growth regulator is applied before the awns start to appear – a late application as the awns are emerging can damage the emerging ear. The T2 fungicide program should now be planned for winter barley. Properly protecting the top three leaves and ear 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 compromise 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.

Spring Cereals

To minimise the effects of competition on the crop and optimise the level of weed control, herbicide application should be carried out once all 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 is much more effective especially on difficult weeds such as fumitory and knotgrass, rather than delaying to coincide with the 1^st fungicide application.

Broad leaved weeds resistant to certain herbicides in NI is not a new problem – continuous use of straight metsulfuron (ALLY) in previous years has resulted in strains of chickweed that are no longer controlled by this chemistry. Sulfonyl urea (SU) herbicides such as metsulfuron have a single mode of activity, blocking the production in many BLW of a key enzyme, acetolactate synthase. Products that use this mode of activity are known as ALS inhibiting herbicides and include the SU chemistry. ALS resistance is becoming a bigger problem with other weeds now developing this type of resistance, including mayweed and poppy. This development seems inevitable following the continued use of products with the same single mode of action, and more than ever mixtures of products with different modes of activity are essential to maintain good weed control. ALS inhibiting herbicides must therefore always be tank-mixed with another non ALS herbicide to ensure satisfactory weed control, especially of chickweed in NI.

Leatherjackets

Leatherjacket numbers are very high this year with widespread damage seen in recent weeks to new leys and established grass swards particularly in the west of the province. Damage will become evident as spring crops emerge, leaves and whole plants yellowing, cut off just below ground level. Crow activity is also a sure sign of leatherjackets being active. Crops most at risk are those drilled into old ley or dirty stubble, but monitor all emerging crops closely for signs damage. Feeding activity and therefore the likelihood of damage will increase as soils warm up as the leatherjacket continues to feed for some weeks yet before hatching out in late May / early June.

Growth Manipulation

Since tillers are a critical component of yield and tiller numbers decline the later the crop is drilled, it is important that these crops be encouraged to tiller to improve yield potential. Because of the more rapid progression through the growth stages than the winter crop, the growth regulator must be applied very early to maximise the suppression of the main stem development (apical dominance) and therefore divert nutrients and growth to promote tiller development. Optimum timing for barley is from the 2 expanded leaf stage to beginning of tillering, GS12–21; in wheat the optimum timing is slightly later, 5 leaf to mid tillering, GS15-24. SELON is the only chlormequat product approved for use on spring barley. Because an early application suppresses the main stem development and so diverts the growing efforts to the tillers, this extra growing effort also increases root development in the plant, improving crop establishment, stem base lodging (not brackling) and yield. This treatment also gives a consistent straw shortening effect in wheat, but not in barley.

Horticulture

The recent frost has had serious implications on many of our horticultural crops especially the apple and early potato crop.SEAMAXX is a seaweed based fertiliser that can help improve resistance to environmental stress such as extreme temperature, wind damage and drought. It helps the orchard to maintain growth during hostile growing conditions, by reducing stress there is more energy available for flowering and fruit set leading to improved yields. At this critical time MACANNI should be applied as it is safe through the blossom.

With temperatures rising, days getting longer and top dressings kicking in, crops are starting to come away, especially those on drier soils. Soil temperatures have not dropped as low as usual with the milder winter and therefore the early start to growth comes as no surprise and is encouraging in terms of building yield. Leather jacket numbers remain high and all crops should be monitored closely. Now is the time to spray autumn reseeds to ensure weed competition does not choke out the young grass.

Winter Barley GS30 – GS31

All crops have completed tillering, with the most forward fields past 1^st node, GS31. Most are looking well considering the wet conditions over the winter. There are good plant counts and tiller numbers, but the mild winter means disease is already well established on these young plants with Rhyncho, mildew and net blotch showing in all.  Rhyncho remains the most damaging disease of barley, seriously damaging yield potential if not controlled quickly and effectively.

Winter Wheat GS22 – GS30

Growth stages vary widely depending on drilling date but most are at various stages of tillering. Most have good plant numbers but some fields have suffered from poor seedbeds, waterlogging, slug and leatherjacket damage. As temperatures rise slugs and leatherjackets are still a threat to more backward crops and should be treated if any new damage is seen. Septoria is established in all crops but particularly so in earlier drilled fields.

Disease Control

Rhynchosporium and Septoria are the two most damaging cereal diseases in NI. Both have always been more effectively controlled protectantly, but in previous times where the curative properties of the azoles were able to rescue a bad situation later, particularly in wheat this is no longer the case. Growers must now change their approach, looking to keep ahead of both diseases by starting earlier than before and maximising the protectant activity of the chemistry available then right through to crop senescence.

Timing of fungicide applications and rates used are every bit as critical as product choice to achieve the maximum potential response. To ensure the main disease programme persists right through to ripening, it is adviseable that all crops should have by now have received a T0 fungicide. Farmers should not apply their main T1 fungicide application before about the middle of April, with the T2 and T3 applications following at 4-5week intervals, ie mid-May and mid-June. This T1 timing should coincide with the beginning of stem extension between 1^st and 2^nd node, GS31-32.

Holding the T1 timing to GS31-32 should ensure T2 in barley and T2 & T3 in wheat be optimally timed to avoid extended gaps, maintaining persistency right up to and during senescence. Where a crop has not received a T0 treatment product rates at T1 will need to be increased to take account of this.

Since their introduction, fungicide programmes containing SDHIs, or succinate dehydrogenase inhibitors have consistently out-performed triazole only programmes. These are the newest family of chemistry available to cereal growers and now considered the mainstay of disease control programmes. They work by inhibiting fungal respiration and are more effective at controlling a range of diseases than older products, particularly as the performance of triazoles continue to decline each year. However SDHIs only have this single mode of action and therefore resistance and the associated breakdown in control is a very real threat to these products. To try and prevent resistance building up against the SDHIs, they must be used only twice in a season and in conjunction with another fungicide, such as a triazole, with a different mode of action. Of the SDHI products available, penthiopyrad (in AYLORA) has proven to the most effective performer on both Septoria and Ryncho. Boscalid (in WHISTLE or KINGDOM) remains the strongest active available to control Eyespot and therefore a very good option for use on wheat at T1.  CONCORDE containing isopyrazam and cyprodinil will be widely used as T1 on barley this season. This is an SDHI mixture proving to be very strong on both eyespot and ryncho.The T1 treatment in oats should be applied at the same time as the growth regulator. Whilst traditionally a single fungicide program was often used on this crop, a 2-spray program consistently outperforms a single spray in terms of yield, bushel-weight and profitability. CAPALO is the strongest T1 treatment available in oats, giving excellent curative activity on Crown Rust and Mildew when applied at 1^st–2^nd node (GS31-32), and is very persistent keeping new growth clean right up to full flag leaf (GS39) when the T2 is applied.

Weed control

While most crops received a herbicide treatment in the autumn, for those still to be treated, control of Annual Meadow Grass (AMG) is the most pressing issue. OTHELLO is an excellent option for AMG in wheat into the spring, however there is no similar late option for barley. Note that OTHELLO will only control AMG that has already emerged; unlike the autumn products it has no pre-emergent activity. Where the AMG has been controlled in the autumn but for example chickweed, cleavers or groundsel is likely to be a problem, SPITFIRE is an excellent stand-alone broad spectrum herbicide controlling these and most other emerged BLW. It also works best when the weeds are growing actively and has post em activity only, therefore delay use until all cleavers have germinated and temperatures have risen to encourage growth. SPITFIRE is also an excellent tank-mix partner with OTHELLO.

Growth regulation

When applied before 1^st node, GS31, application of certain chlormequat growth regulators can significantly increase tiller numbers. Chlormequat works by suppressing apical dominance, ie main stem development. In doing so it diverts the plant’s resources into producing and supporting more tillers. Particularly in wheat but in barley also, more tillers will go a long way towards compensating for low plant counts, ultimately increasing yield.

Correct timing is critical to maximise this effect. The earlier it is applied during tillering the greater the tiller effect, but note early application to increase tiller numbers will also reduce its effect on lodging. Application of a chlormequat based growth regulator often goes on with a T1 fungicide application sometime around 1^st-2^nd node, GS31-32. At this timing it is too late to affect tiller numbers and survival but will maximise the stem stiffening effect.

Early application will also increase root growth and so reduce stem-base lodging. 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. All winter crops have rooted very shallow this season as a result of the persistently wet conditions and therefore stem-base lodging is likely to be a significant problem later this season.

SELON can be tank-mixed with the herbicide and where the crop has begun to tiller, should be applied now.

Nutrient Deficiency

A combination of waterlogged soils, plants already suffering from restricted nutrient uptake and plants now trying to grow is showing up Mn deficiency in many barley crops. 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.

As soon as the ground allows, Mn deficiency should be addressed and applied as soon possible along with the SELON application to increase tiller numbers.

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 immediately symptoms are seen.

With air quality significantly improving over the last two decades, the most important source of sulphur to the soil coming from the pollutant gas sulphur dioxide has also reduced significantly. Whilst its deficiency is now being recognised and corrected on grassland through the application of high sulphur compound fertilisers, its impact in cereal crops in NI has by and large been misidentified or overlooked. After nitrogen, phosphate and potash, sulphur is the next most important element required by all crops, used to make essential sulphur containing amino acids and proteins in all plants. Soil sulphur is easily leached especially from light to medium soils, making shallow-rooting plants particularly vulnerable to deficiency. Deficiency causes paling in the cereal plant, caused by a reduction in chlorophyll production and even in the absence of any symptoms, decreased efficiency of nitrogen utilisation. Whilst often mistaken for lack of nitrogen, sulphur is not very mobile within the crop and therefore deficiency is most pronounced on the younger leaves; the opposite to nitrogen deficiency which affects the oldest leaves first. Crops of both wheat and barley with high yield potential are particularly responsive to one to two applications of foliar sulphur at the timings of rapid growth.

All T3 fungicide applications onto winter wheat should now be planned for application over the next week.  Winter wheat crops have moved at exceptional pace during the dry warm period over the last couple of weeks.  The cornerstone for the T3 head spray fungicide is a strong triazole that as well as being effective on Septoria is also effective on Fusarium.  Prothioconazole & epoxiconazole remain the most effective products to give ongoing Septoria protection.  Tebuconazole and metconazole are very strong triazoles for Fusarium and an important contributor at this time. The addition of a strobilurin is also essential to maximise the persistence of the triazole and strengthen 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.   Last years’ HGCA trials show pyraclostrobin (COMET) to be the highest rated strob for use in wheat being the strongest performer on Yellow rust and the late ear diseases. Products containing the active prothioconazole are in short supply this season and therefore an alternative choice may be required.  I have seen a lot of physiological tipping on winter wheat and there are a lot of theories as to what may have caused this but most noticeably it seems to be specific to certain varieties.   Mildew has been present on most cereal crops this season where the variety has low resistance a mildewicide must be included in the fungicide program.   All weed control should now have been carried out on spring barley crops and all should now have received the T1 fungicide application as rhyncho is present on most varieties. Concerto and Waggon both have a very low rating for rhyncho resistance.   The two most dominant diseases in our climate are powdery mildew and rhynchosporium with ramularia becoming an increasing problem over recent years.  Ramularia can be difficult to identify but unlike most other physiological leaf spots which are only visible on the upper side of the leaf ramularia is easily seen both on the upper and lower surface of the leaf and the longitudinal edges of the brown lesions remain enclosed by the leaf ridges. 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.   Where growth regulation has not been carried out it is critical to check crops and apply Cerone onto crops beyond GS32 if required.   Moddus can be used on crops which have not yet reached GS32.

All weed and disease control should now be complete on both spring wheat and oats.

Grassland

Attention must now be given to those grass fields which were not sprayed prior to first cut. 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.   Forefront T is the most effective herbicide on ragwort.

Stock must be kept off until the weeds have rotted away, which can take up to six weeks.

Potatoes

Where broad –leaved weed control has yet to be completed and the crop has passed the latest timing for Sencorex a reduced rate of Sencorex tank-mixed with Titus will provide a wider weed spectrum of weed control than Titus used alone and can be used on emerged crops up to 25cm high where the label allows .Scutch, other grasses or volunteer cereals are not controlled by the Titus/Sencorex mix. Where these weeds become a problem in coming weeks the graminicide Shogun can be used. Shogun can cause transient yellowing and is therefore not approved for use on seed crops.

As canopies close, the soil surface will tend to remain damper, encouraging slugs onto the soil surface. Timing is critical for effective control, just before the crop meets across the rows. Take advantage of any rainfall by applying pellets just afterwards, as this will bring slugs up onto the soil surface. Potato varieties particularly susceptible to slug damage include Maris Piper ,Desiree and Kerrs Pinks.

Blight fungicides move through the plant in three different ways contact, translaminar and systemic.  Dithane,Ranman Top, Shirlan and Tizca are all contact fungicides. These Products protect only the outer surface of the leaf onto which they are deposited.Translaminar products such as Curzate M, Invader, Resplend and Revus move into the leaf and redistribute throughout the leaf tissue as it increases in size whilst systemic products such as Consento, Fubol Gold  and infinito move in through the leaf surface and upwards into the new growth protecting this from infection also. Products that have zoospore activity are the most effective 1^st spray, applied at the rosette stage prior to rapid haulm growth. Shirlan or Tizca will control any zoospores that may be in the soil and provide good protection of the new plant.   During the main canopy development phase with the considerable amount of new growth 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 drilled crops, at a time when the level of inoculum in the air is progressively increasing. 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 adhesions onto the leaf immediately post application and over the following days should rainfall levels remain high. The way the blight product is applied is as important as the product choice. Make sure nozzle type used is correct to ensure sprayer pressure; droplet size and water applied is as directed on the label. Inspect and calibrate nozzles regularly to maintain performance.   Never use any blight product at reduced rates.  Do not spray when the leaves are wet as this will significantly increase the likelihood of runoff.

The mixed weather and below average temperatures have certainly made things difficult for both arable and grassland farmers recently. We have almost accepted there is no such thing as the norm anymore. It has been very frustrating for farmers trying to grab any available opportunity to spray crop as ground underfoot has become very soft. Conditions however have been ideal for weed control onto potatoes and veg as residual herbicides require moisture to work effectively.

SPRING CEREALS

The above average rainfall over winter has depleted many soils and it is essential to replace essential nutrients. Spring barley crops grown on low PH soils with a low P index seem to be struggling most this season. This must be rectified with lime and Phosphate fertilizer in accordance with soil analysis.

An application of a balanced and rapidly available source of macro & micronutrients at this key time will minimise the adverse effects of restricted soil nutrient uptake. CEREAL HIGH N supplies 3.7%Mn, 1.5%Mg, 1.8%Cu, and 0.6% Zn in the most rapidly available form to the plant through the leaf and also supplies high levels of Nitrogen and Sulphur.Potash deficiency is also showing up in many spring barley crops with pale green yellow tips being the first symptom.Deficency is most likely on light sandy soils or in crops following intensive grassland. Manganese deficiency is also appearing on crops especially those in a continuous cereal regime or where lime has been applied recently. A foliar application may be applied along with the weed control.

To minimise the effects of competition on the crop and optimise the level of weed-control, herbicide application should be carried out at the earliest opportunity, once all the weeds have emerged but are still small, and before they begin to compete with the crop for nutrients and light. With low soil temperatures since drilling, weeds are not coming through as rapidly as expected but chickweed is beginning to choke out young plants and must be sprayed as soon as possible.

Product choice will depend on the weed type and size present and the crop growth stage. Broad leaved wise, Sulfonyl-urea (SU) herbicides will likely be the starting point, controlling a wide range of weeds and very safe to the crop. Options are ALLY MAX covering a wide spectrum of BLW with the max formulation giving improved control of polygonums & other BLW over the old ALLY formulation. HARMONY SX controls a wide range of BLW at sizes larger than any other SU. 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& fat-hen). Ideal partners are COMPITOX controlling (chickweed, fat-hen, fumitory), OXYTRIL CM controlling (field-pansy, red dead-nettle and speedwells) and SPITFIRE /MINSTRELfor chickweed and cleavers.

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, sulphonyl-ureas products will improve control. AXIAL gives excellent control of wild and tame oats in spring barley and spring wheat and has an excellent window of opportunity. Application should be held off until at least 6 weeks after drilling to ensure all wild oats have germinated. It can then be applied up to full flag-leaf of the crop and full flag leaf of the wild oatGS39, allowing a minimum of 21 days to have elapsed after application of the BLW herbicide. The wetter ADIGOR must be used in all situations along with the AXIAL.

WINTER WHEAT

Most crops are now at flag leaf and i have been in crops with ears emerging last weekend.Septoria tritici is present in most crops at variable levels depending on T1 timing but with recent weather; expect levels to rise if fungicide rates and timings are not correct. Mildew is present on almost all winter wheat varieties and a morpholine based product should be applied to clean up the crop. The inclusion of Talius in the program will give very good persistent control of mildew. Of all fungicide treatments, T2 has the greatest impact and response in terms of grain yield and quality, keeping the top three leaves clean and the ear as it emerges. The dose rate applied must be sufficiently robust to ensure long term protection of the flag leaf plus eradicate disease already present on the lower two leaves that also contribute to yield.  Epoxiconazole & metconazole in mixture will form the key part of the T2 fungicide onto winter wheat. Tri morpholine should be included azoles continue to form the backbone of all treatments but with their performance continuing to decline, SDHIs are now regarded as essential partners to maximise the yield of all crops with any reasonable potential, with the most responsive timing for the newest SDHI molecules being at T2. Growth regulator must also be applied at this time where required.