The Art and Science of Spray Application by Syngenta UK Limited

The Art and Science of Spray Application Tom Robinson

The Art and Science of Spray Application

Index Principles of successful application

With modern crop protection products it is possible to achieve exceptionally high levels of pest, disease and weed control. It is those spray operators who pay absolute attention to the finer points in the Art of Application, who can make the crucial difference between an acceptable 95% control, and an outstanding 98% or more.

Rest of index to follow as pages created

Tom Robinson Syngenta Crop Protection

The purpose behind this book, is to enable operators to reconcile the requirements of targets, products, spraying equipment and timing, to get the best possible results every time. It also addresses the essential areas of spraying stewardship and avoiding problems of waste, with a host of practical tips and guidelines to better spray application. The unique combination of proficiency tests for operators via the National Proficiency Test Council (NPTC), annual training for Continuous Professional Development via The National Register Of Sprayer Operators (NRoSO), and annual sprayer testing with National Sprayer Testing Scheme (NSTS). Have encouraged correspondingly high standards of spraying in the UK. Improving general standards is all about passing on good practices developed by individuals. The book contains some of the best practices from recent Finalists in the Farm Sprayer Operator Of The Year Award.

The Principles of successful application Achieving the all important effective result from crop protection products is a function of three main factors:

Application Techniques Evolving

• Product choice • Timing of application • Application technique Correct product choice is half way to achieving a good result. Putting it on at the right time is the second most important factor; control of black grass falls off very rapidly after the weed reaches the second true leaf stage, for example, and wheat crops lose an average 0.5t/ha potential yield for every week the T2 spray is delayed. Ensuring the sprayer is in top working order, the optimum choice of nozzle fitted and paying attention to the details of the spraying process, however, can make all the difference in achieving the best result. Fitting the correct nozzle for the job could improve black-grass control from 90% up to 99%; a nine percent improvement in control gives a 1,000% reduction in seed return.

The modern spraying operation has to cover greater areas, with fewer machines. The result is larger, more sophisticated machines, capable of operating at higher speeds. Innovative new technology with wider booms, active suspension, computerised control, GPS technology and better nozzles designed specifically for agricultural applications and improved products all contribute to a better result. Since the launch of the Amistar Nozzle in 2002, sprayer technology has developed enabling faster forward speeds and wider booms. The operator has to be far more precise at constantly adapting spray application to the target and to the prevailing conditions. Changes in the way sprayers now operate demands a whole new way of looking at the physics of application.

Targets Targets for spray application vary enormously from bare ground to upright-leaved cereals, to horizontally-leaved potatoes and oilseed rape. Crop structure also changes as plants develop. The operator’s aim is to get the most droplets to hit the target. Pinpoint accuracy is never possible, but tipping the balance of spray distribution certainly is.

Spray Quality - Medium (v.m.d 250 um)

Application requirements for the best results are a function of: • Retention • Coverage • Distribution The emphases on these functions varies between products and targets.

Spray Quality - Course (v.m.d 500 um)

All spray nozzles produce a spectrum of droplets: some fine; some medium and some coarse. Large nozzles tend to produce more coarse drops, while small nozzles tend to produce more fine drops. Droplet size is important.

Drop size and retention In general, small drops are well retained on plant surfaces, particularly shiny ones, where large drops tend to bounce off. Fine sprays are important for retention on difficult to wet grass weed leaves such as wild oats and black grass, as well as pea crops.

The best result will always be obtained by applying the right product at the right time with the best nozzle for the job. However, the demands of optimum timing and nozzle choice, may conflict with application conditions on the day. By developing new types of Nozzles and Application Techniques, Syngenta Crop Protection have specifically addressed these issues.

Traditionally UK sprayer operators have used 11004 fanjet nozzles running at 2.5 bar pressure, and traveling at 8 km/h to apply 200 litre/ha for virtually all applications.

Spray Quality - Fine (v.m.d 170 um)

All nozzles produce a spectrum of droplet sizes, but the proportion of small, medium and coarse will vary. Operators can use this to tailor droplet size to the crop structure and the spray target. 3

Large drops are however surprisingly well retained on easy to wet leaves leaves such as mature cereal plants, beans, potatoes and many broad leaved weeds.

Spray Deposition in Cereal and upright Plants

Adjuvants also have a considerable influence on the retention of sprays. By reducing the dynamic surface tension of the spray drop, they can reduce the amount of rebounding drops. There are two further ways of making large drops stick to a target:

2) Put a shock absorber into the drops These are the principles behind the air-induction Amistar Nozzle.

Drop size and coverage

Drop size and distribution Lets assume we are spraying with a conventional vertically oriented fan jet. Penetration into the crop is one of the key factors that will govern the performance of a spray. Cereals present a 4

Small droplets provide far greater leaf coverage for a given volume of spray. For systemic products such as Touchdown just a few drops containing sufficient ai will be fine, but for contact herbicides, such as Gramoxone, good leaf coverage is important. Photo: Moritz Knoche very upright target, and coarse drops which fall vertically tend to penetrate well. In a broad leaved crop, the opposite occurs, as coarse drops falling vertically tend to impact on the top leaves, and do not penetrate. For penetration in potatoes, a fine spray is preferred, as the fine drops move horizontally, and penetrate between the layers of the leaves. Sprays can also penetrate sideways into a broadleaved crop by firing them sideways with an angled nozzle. This is far more effective, and safer to the operator crop, and bystanders than relying on a fine spray.

Spray penetration in Broad Leaf Crops, Key for Plover, Fubol, Shirlan etc

Forward movement and wind speed will have a significant effect on the behaviour of the spray pattern. The effect of wind on spray drift can be clearly visible. Larger droplets are less affected, as they move to the target quicker. Small droplets travel very slowly, or may stop completely, shortly after leaving the nozzle. They move sideways significantly, even moving up in air currents, before falling some distance away. Turbulence generated by the spraying machine is generally bad news. Lighter slow moving spray drops are caught up in the turbulence, and donâ&#x20AC;&#x2122;t want to land in the crop.The problem has been exacerbated by the speed of modern spraying operations; the faster you go, the greater the air turbulence created. For every doubling of forward speed, the turbulence factor is increased by four. Small increases in forward speed make a significant impact, as does spraying into the wind v. downwind.

For a given volume of liquid, when the drop size is halved, the number of drops produced goes up by a factor of eight, and the coverage of a flat area of leaf or ground may be up to four times greater. So where the target is very small, such as blackgrass at the two-leaf stage, a fine spray will greatly increase the chances of hitting it. However, while a finer spray will in principle increase coverage, it is also less controllable. In practice the best way to increase coverage is by increasing water volume.

1) Slow them down

The Turbulence Factor

In cereal and upright crops large droplets rapidly penetrate to the lower leaves, whilst small droplets are retained at the top. In broad-leaved crops, such as potatoes, large droplets are intercepted and it is the smaller droplets which penetrate.

The incidence of spray drift can be reduced by reducing the boom height, increasing the size of droplets, reducing spray operating pressure and slowing down. However, in some instances this could lead to a compromise in quality of the spray application and results. Turbulence generated by the crop, is generally beneficial. A moving crop will generally collect more spray than a stationery crop. Operators must also take account of the crop structure and prevailing weather conditions. 5

Spray at 4kmEnergy: 1 Spray Control at Control 4Km Air Velocity Air Velocity Energy: 1

Spray at 8kmEnergy: 4 Spray Control at Control 8Km Air Velocity Air Velocity Energy: 4

The less crop present at the time of application, the worse drift is likely to be. A moving cereal crop at T2 application timing, for example, creates its own air movement to effectively suck the spray down into the crop; in very still conditions there is a greater chance small droplets will move in air currents. Bare ground creates little turbulence to drag down the small drops, so drift risk is high. Bigger droplets that quickly fall to the ground are by far the most effective.

Nozzles are the ultimate controller in a spraying system. They must be kept clean, calibrated and regularly replaced. Spray 12kmEnergy: 9 Spray Control at Control 12Km Air at Velocity Air Velocity Energy: 9

> Faster speeds increases turbulence behind the sprayer and makes the pattern more difficult to control. Operators must employ new techniques to help if they are to avoid compromising some spray applications by simply increasing droplet size. 6

Traditional advice advises regular testing to ensure consistent output per nozzle within +/5%. In reality the prospect of a 10% variability between nozzles is too much and cannot ensure an effective operation. Ideally one is looking for less than 5% variation between the output of the nozzles. The cost of this is small relative to the value of the products passing through them, and the penalties of reduced control; a set of quality conventional plastic nozzles costs ÂŁ125 for a 24m sprayer compare to the average spend of over ÂŁ130/ha on chemicals in a wheat crop.

Nozzles should be renewed each year.

Flat Fan - 110o and 80o Fan nozzles are the most widely used in agriculture. Their virtue is that they have a mixed spectrum of droplet size which allows the delivery of an effective dose to a wide range of targets when running between 2 and 4 bars, and when operated with the correct overlap, produce a uniform distribution across the ground. 1100 nozzles have the advantage that they can be carried closer to the crop, and are less sensitive to boom roll. 800 nozzles produce a coarser spray than 1100 and are therefore less drifty. Conventional fan nozzles are designed to work at pressures of 3 Bar and above. However, the development of Variable Pressure (VP) or Extended Range (XR) nozzles provides the operator with far greater flexibility. In my view they replace the need for conventional fan jets. These nozzles can be operated at significantly reduced pressure, whilst still retaining a 1100 fan angle for crop coverage. A VP nozzle working at 3 bar, for example, will produce a medium to fine spray , but if reduced to 1 bar will produce a medium to coarse spray. In practice, operators can alter pressure to the prevailing weather conditions to minimise risk of drift. Reducing pressure from 2.5 bar to 1 bar results in a three-fold reduction in drift. It can make all the difference in completing a job when conditions deteriorate.

Nozzles

Nozzle types

Variable pressure Fan-Jet. Jack of all trades. match or exceed the capability of standard fan nozzles. The potential pitfall of the VP style nozzle is that they are more drifty than a conventional fan jet when used at conventional pressures of 2-3 Bar. You have to drop the pressure to get the drift reducing benefits. Relative drift from different nozzle types Relative Nozzle Type Droplet pattern spray drift Air Induction Very Coarse 1 Low Drift Coarse 4.5 Conventional Medium 9 Fan Medium @ 3 bar 10 Variable Pressure Coarse @ 1 bar 3

In terms of relative spray drift, VP fan nozzles can outperform low drift nozzles and still achieve better results. In good conditions VP nozzles will

Hollow cone

Low pressure nozzles - 1100 and 800

Hollow cone nozzles produce a finer spray quality than fan jets at like pressures. They also produce a less even distribution and are more sensitive to boom height variations.

Low pressure nozzles are designed to give large drift reducing droplets when working at pressures between one and two bars. The relatively large droplets are great for soil acting herbicides. Low pressure nozzles are slightly less prone to blockage than pre-orifice nozzles.

Pre-Orifice (Low Drift) Fan - 1100 Largely superseded by air induction nozzles. Low drift nozzles are designed to work within the 2 to 4 bar pressure range, but produce significantly less drift than a conventional fan tip. They actually operate at a relatively low tip pressure because the liquid is forced through a small pre-orifice which drops the pressure before the tip. Typically they produce a coarser spray, and about half as much drift as an equivalent conventional fan jet. Their performance is similar to a Low Pressure nozzle, Syngenta trials have proven these tips to work well with cereal fungicides and with autumn residual herbicides. The role of the Low Drift Nozzle in modern farming, is now questionable, as air induction nozzles are much better at reducing drift, and variable pressure nozzles offer greater flexibility.

Operators must be careful that diaphragm check valves operate correctly at the low pressures associated with these nozzles.

Angled sprays, Twin outlet caps and twin orifice nozzle tips A twin outlet nozzle tip, or two half-rate tips mounted in one specially designed bayonet cap, give a finer spray quality than that from a single tip working at an equivalent application rate. Furthermore, the fore and aft angling of the outlets results in better penetration of the spray into a broadleaved crops. These nozzles are particularly good for Vegetables, Amistar in peas, carrots, brassicae, and onions having the increased deposition and penetration advantages of hollow cones, while producing less drift, and a more even distribution across the boom. The potential problem has been the small orifice of two half-rate nozzles used when applying relatively low water volumes, increases the risk of nozzle blockages and spray drift. The other key use for these nozzles is where the label requires a high water volume combined with a medium or fine quality spray. By choosing appropriate nozzles you can also travel at higher speed while applying a high water volume at

The Syngenta Potato Nozzle a normal spray pressure and quality. This is particularly useful for applying Reglone for potato desiccation - with 2x 11003 nozzles will apply 200 l/ha at 12 km/h. A simpler solution to the angled spray conundrum has been the advent of the Syngenta Potato Nozzle. The nozzle fits directly into a conventional bayonet, but is designed to angle the spray at the optimum angle for crop penetration (See Page x). The nozzles should be mounted alternately facing forward and back along the boom, for best deposition and best drift control.

The Syngenta Defy Nozzle is a further development of the angled nozzle technology. It is optimized for pre-emergence applications of Defy, and its spray characteristics give it a wider range of operating conditions than the Hawk Nozzle.

Air induction Nozzles Significant reductions in drift have been obtained with the advent of air induction (AI) nozzles. Spray passing through the nozzle pre-orifice sucks air in through a venturi hole and mixes it with the

The even coverage of the complete crop leaf and stem with the Syngenta Potato Nozzle has been shown to work most effectively for all potato blight products and end of season desiccation with Reglone. More recent developments include For grass weed control in cereals the Syngenta Hawk Nozzle features a variable pressure

The Syngenta Hawk Nozzle is also recommended for autumn Fusilade Max applications in oilseed rape, where increased sideways movement of droplets can target grass weeds hidden beneath the emerging crop canopy. >

Traditionally, hollow cones have been for late applications in cereals where good cover and keeping the spray in the top of the crop is important, such as a late spray on the ear and flag leaf of cereals. At modern faster forward speeds, Hollow cones no longer seem to be a useful choice, as the finer spray is badly upset by turbulence from the sprayer.

design producing the ideal spectrum of medium fine droplets to target small black-grass and wild oat seedlings. VP capability can significantly increase the days available for autumn grass weed control.

Air inclusion - Amistar nozzles 9

Syngenta trials have shown good results with cereal fungicide applications for Cherokee at T1 and Amistar Opti at T2 and T3, leading to the development of the Syngenta Amistar Nozzle. Using the attributes of the AI nozzle, it creates the ideal droplet size and spray angle to give even coverage of the cereal crop ear and top leaf. The original Amistar Nozzle was designed to apply 100 l/ha at 12 km/h. It generates the most drops per litre of any similar sized ai nozzle, holds the pattern down to 1 bar pressure and creates an even spray deposition on the front and back of the target crop ear. The nozzle is currently the only AI nozzle with LERAP approval for use at 12 km/hr. In 2008 the G0-Faster 035 Amistar Nozzle was developed for speeds above 14 km/h.

Twin Fluid Atomisers / Airtec and AirJet Sprayers Spray mix under pressure is mixed with air under pressure in a specially designed nozzle with a large orifice which tends to reduce blockages. By altering the balance between liquid and air pressure an operator can adjust the spray quality while maintaining application rate. Airtec users like to operate at water volumes between 70 and 100 l/ha. 80 l/ha has proven to be an effective volume for Airtec-type sprayers. The equipment has two key advantages to the farmer; high work rates, and reduced drift capability on the move. However, operators need to be aware that there is a temptation to coarsen the spray to reduce drift, which may lead to reduced efficacy. Twin fluid sprayers produce less drift for a given spray quality, so it is preferred that they apply Axial and Topik as a fine spray. Syngenta products generally perform as consistently through twin fluid sprayers as through conventional equipment,

For contact action materials, best suited to application at higher water volumes, operators should fit the appropriate conventional nozzle in place of the Airtec. However, if this option is not available, the best compromise is to increase the Airtec water volume to 100 l/ha, and apply as fine a spray as possible. Do not expect it to work as well the conventional nozzle. The spray quality from an Airtec is infinitely variable. This variability may be used in the same way as the extended range nozzles to increase the spray window.

Sleeve Boom Sprayers / Degania, Kindestoft, Hardi Twin The principle is to entrain the spray in an air stream, and to replace the air in the crop with air from the sprayer, thus reaching all the vegetation in the crop. Get the balance of crop volume, air output, boom height and forward speed correct, and excellent results will be obtained. Syngenta trials in the early 90â&#x20AC;&#x2122;s found these novel sprayers often produced better results than the conventional fan jets available at the time. For best effect, a fine spray needs to be applied. Where problems arise it is because the operator has a poor understanding of the machinery and its principles. Usually this involves the use of too

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Where drift avoidance is of paramount importance, these are the hydraulic nozzle of choice.

Amistar Nozzles are recommended for late applications of Axial on Wild Oats.

with a few exceptions; Fubol Gold, Shirlan and Reglone, have given variable results, and we do not have enough data on how to get consistently good performance with these products.

Although the drops are larger, size for size, an air filled drop tends to be better retained than a large solid drop the air acts as a shock absorber. The physical performance of different brands of air induction nozzle varies considerably. The Syngenta Amistar nozzle is designed for maximum spray retention while optimizing the sometimes conflicting needs of best coverage with least drift.

In addition to T1, T2 and T3 fungicide applications in cereals the Amistar nozzle hasalso been usedfor Amistar and Bravo fungicide applications in beans, desiccation and stubble cleaning with Touchdown.

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spray liquid to produce air filled droplets. The drops are much larger relative to those produced by a conventional fan jet. Currently there is no classification system for the air filled drops.

ERATOR OP

How to check the nozzles at the back of the sprayer Gareth Morgan Gareth Morgan has CCTV cameras mounted facing inwards on both spray booms. This not only makes reversing safer, but enables him to ensure the nozzles behind the sprayer are working correctly. Sprayers without CCTV should be checked at least once a day when washing out. much air leading to excessive spray drift, and sometimes inefficacy and crop scorch. A classic symptom of applying a product with too much air is poor disease control and damage to the outside leaves. The greatest risk of drift is when crop cover is minimal, as it is with conventional spraying, but worse. For pre-emergence and early postemergence applications, operators should fit fan jets, and turn the air right down, or even turn it off. Operators of these machines need to be keen and well trained.

As a result of this decision, one can legally reduce the spray volume of an approved pesticide to 10% of the minimum label volume with certain exceptions. The principal exceptions are listed below: Further information on reduced volumes can be found in the DEFRA Code of Practice For Using Plant Protection Products section 4.6.4. Potential spraying time is often wasted during travelling and refilling, so sensible water volume reduction is one of the biggest contributors to productivity, more timely spraying and as a result better product performance. Generally operators find that cutting the spray volume from 200l/ha to 100l/ha increases work

Constraints on reduced volume application Label prohibits reduced Product is classified Label requires use of volume spraying at as:- Very Toxic, Toxic, ppe when pesticide is recommended dose, or Corrosive, Risk of diluted to the minimum has maximum statutory serious damage to eyes volume rate at the concentration recommended dose Reduced volume allowed as long as maximum concentration recommended on the label is not exceeded. Reduce product dose in line with reduction in water volume, e.g. half the water volume permits half the dose rate 12

All other products

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Most Syngenta products perform equally well at a water volume of 100 l/ha as at 200 l/ha. The principal exceptions are contact herbicides on large weeds, along with blight sprays in potatoes such as Fubol Gold and Shirlan and some vegetable crop applications. The use of twin-fluid air injection nozzles, as found on an Airtec or AirJet,sprayer, and the use of air assisted sleeve boom sprayers can enable reductions in application volume, down to about 70 l/ha. This gives operators the advantage of very high work rates. Syngenta trials have shown that reduced volumes generally result in increased spray retention on the target.

Advantages and risks of water volume reduction The time saving with reduced water volumes = more hectares/day = more timely spraying, which frequently improves efficacy. It can make the difference between optimum timing, and missed opportunity. However, a reduced water volume may make the spray ‘hotter’ when a plant is under stress or the wrong sort of weather follows application. Where a high degree of coverage is known to be necessary, such as dessicating Potatoes with Reglone, efficacy may be reduced. The legal constraints on reduced volume application are shown in the table to the left.

Full dose can be used up to 10 times the permitted concentration

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Where high levels of penetration are required in dense crops, particularly some vegetable crops a higher volume may be recommended at anything up to 1000 l/ha. Some products have a lowest permitted volume in order to safeguard efficacy, crop or operator safety. However in Syngenta cereal application trials, increasing water volumes above 200 l/ha has been found to have little if any effect on increasing spray penetration, and generally reduces the amount of product adhering to the plant.

When the Food and Environment Protection Act (FEPA) was introduced in 1985, the regulators decided that there had to be some flexibility on water volumes, or there would be little incentive to develop new and improved application techniques.

rate by 30% - covering 130ha a day instead of 100ha, for example.

Traditionally much of the UK spraying has been done at 200 l/ha and most of the initial trial work on new products is still carried out at this rate, using flat fan nozzles – hence the standard label recommendations. In practical field situations, however, most Syngenta products work equally, or more, effectively at reduced water volumes, typically 100 l/ha.

How much can they be reduced ?

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Water volumes

ERATOR OP

Rapid Sprayer Filling Andrew Myatt Filling a sprayer with water generally takes 10 minutes, while adding the chemical can take 3 times as long. Andrew Myatt built a 600 l ‘induction hopper’ out of an 800l bulk container, which cut sprayer filling time by more than half. It is fitted with both a rinse nozzle and rinsing rack, so containers can be rinsed and left to drain whilst he’s spraying, and the washings incorporated into the next fill. He stresses the importance of making such devices with rust resistant materials such as stainless steel.

Spray requirements Pre-emergence, and Post emergence soil applied; Defy Skirmish, Dual Gold. With pre-emergence sprays there is only one target - the ground. An even distribution of the spray liquid is the aim. Patchy weed control most usually comes from patchy application, due to the wrong choice of nozzle and drift. 13

Typically, a standard fanjet puts half the spray on the crop at GS 30/31, the other half is available for weed control, or is wasted to the ground. Later on the amount of spray retained by the crop can be as much as 90% of the total applied. The amount retained is related to the Leaf Area Index. Careful nozzle selection can manipulate this to suit different application targets.

Broad-leaved weed control; > Forward and Backwards Defy nozzles Thebiggest issue is clods. Spray from a fan jet tends to be deposited on the front side of the clods, leaving an unsprayed shadow on the lee side, where the weeds germinate unchecked. A recent Syngenta discovery is the improvement of weed control obtained by using angled nozzles alternately forward and backward along the boom. This gives much better coverage of the lee side of the clods and better control. The Defy Nozzle is optimized for this task.

Applying broad-leaved herbicide products in cereals work well through coarse nozzles, as they aid penetration. However, very coarse spray generators may give reduced control where the target is wiry, such as corn spurrey or mayweed, Syngenta trials have shown pre-orifice Low Drift nozzles to be very effective, along with air induction nozzles. The Amistar nozzle should also provide the right droplet pattern, with the further advantage of variable pressure capability to adjust to spraying conditions.

There are 2 distinct timings for these grass killers. Early post-emergence at the 1-2 leaf stage, and late applications to larger weeds. For applications to small vertical targets at the 2 leaf stage, an angled spray is recommended as it can more than double the amount of herbicide retained on the target. The Hawk Nozzle and the Defy Nozzle are both optimized and recommended for this task. The Defy Nozzle has the advantage of being less drifty than the Hawk Nozzle when operated at a raised boom height of 0.7m or more that some modern sprayers are unable to operate below.

Syngenta cereal fungicides are robust and work well when applied as moderately coarse sprays, and at reduced volumes. Later-applied systemic chemicals only move up the plant, and then only to the next leaf. So the best cover comes from putting chemical on the stem or in the leaf axil, which again suggests that bigger droplets will perform well.

Cereals

> Forward and Backwards Defy nozzles

Foliari-applied grass herbicides; Axial, Topik, Fusilade Max

Fungicides: Cherokee, Amistar Opti, Menara, Bontima

Water volume has little effect on pre-emergence product performance in dry conditions â&#x20AC;&#x201C; even 1000 litres/ha is only equivalent to 0.1mm of rainfall.

Cereals present a tall, thin target. Bigger spray droplets penetrate better into the canopy than fine mist, which is either dragged in by turbulence or drifts away.

These products are sensitive to water volumes. 100l/ha works well on small weeds, but results fall off beyond GS 25 at low volume; 200l /ha is preferred form GS 25 onward.

Low-drift nozzles have proven effective, and good results from air induction nozzles can be expected. The Amistar nozzle has been

specifically designed to achieve the best results with fungicide applications â&#x20AC;&#x201C; providing the ideal spectrum of droplet sizes. Furthermore, the best results with T2 and particularly T3 ear wash applications will be obtained by keeping the spray near the top of the crop, and covering the plant on all sides The Amistar nozzle achieves this at 12 km/h by precisely angling the spray to counteract the forward speed, and producing small air included drops that are big enough to beat the sprayer turbulence, while small enough for good retention.. This provides a complete and even distribution of fungicide on the ear and top leaves. Late aphicides will achieve similar good retention in the target zone with application through Amistar nozzles.

Broad-Leaved Crops Broad-leaved crops present a completely different target to cereals, with horizontal leaves interlocking into a closed canopy. Persuading the spray into that canopy is tricky often only 10-15% of spray ends up where itâ&#x20AC;&#x2122;s needed. Big drops hardly get below the surface, while finer drops can ride in horizontally on air turbulence.

Oilseed Rape Herbicides: Fusilade Max, Reglone Grass weeds in oilseed rape are difficult to hit as they are often protected from the spray by the umbrella like rape leaves. An angled spray 15

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Herbicides: Reglone and Defy

> from the Defy Nozzle or the Hawk Nozzle is the optimum for getting spray beneath the horizontal rape leaves and hitting the vertical grass weeds. For desiccation with the contact desiccant Reglone, spray penetration to the lower leaf and stem is essential. A higher water volume will achieve a better result, but take care to avoid spray drift. The Syngenta Potato Nozzles are recommended for this job.

Fungicides: Plover, Amistar, Priori Xtra Autumn foliar fungicides, such as Plover, will benefit from application through Defy Nozzles alternately forward and back. Traditionally spring oilseed rape fungicides have been sprayed at higher volumes 200-400 l/ ha. Syngenta field trials backed up by extensive farmer trials have showed excellent results with the Amistar Nozzle at 100 l/ha, using a two-spray programme at yellow bud and repeated two to three weeks later. 16

Blight sprays: Revus and Shirlan Angled Nozzles put more spray on small plants at the first application, and penetrate better when the canopy closes over. The nozzle of choice is the Syngenta Potato Nozzle. Blight sprays have consistently performed best at 200 l/ha.

Desiccation: Reglone Desiccation calls for finer sprays and high water volumes. Syngenta trials have shown that the best potato crop desiccation is obtained by a split application of Reglone, with 1 l/ha followed by 3 l/ha. The proportion of the relative split can be varied according to crop conditions. A single application at 4l/ha is less effective than the split, and should be applied in 400l/ha water. The Syngenta Potato Nozzle is the recommended nozzle. The standard split recommendation for water volume with Reglone is 200 l/ha followed by 200 l/ha. Syngenta trials have shown that if the haulm is still actively growing, then best results are achieved with the first spray at 400 l/ha. The second spray when most of the foliage has gone

Boom height Syngenta’s trials have proven that at GS31 in a cereal crop, reducing the boom height from 66 cm to 33 cm above the crop, can increase the amount of spray reaching broad-leaved weeds by 30%. The optimum boom height for Flat Fan jets is 40 cm above the crop.

The forward and backward angled technique developed in cereals is recommended in Potatoes. The angled nozzle of choice is the Syngenta Potato Nozzle. You can keep it in all season. Oilseed Rape being treated with herbicide

See further tank mixing information on page x.

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Potatoes

ERATOR OP

How to monitor your boom at 50 cm above the crop Mark Gardner Mark’s solution is to attach a cable tie to both spray boom ends. Cut the tie 50 cm below the nozzles. While spraying the cable tie should be brushing the crop. should be 200 l/ha. The Syngenta Potato Nozzle angled alternately forward and back is again the nozzle of choice, giving the best all round coverage. Do not use coarse sprays for blight control with Revus and Shirlan, or desiccation with Reglone.

Tank mixes Cereal fungicide/herbicide tank mixes are common at GS30-31. Even cover comes from a balance of big droplets for penetration and finer droplets for swirl. A 110-05 fanjet, running at 2.5 bars is a good compromise, with VP nozzles allowing some flexibility if wind is a problem; as a last resort low-drift nozzles will be effective.

Silsoe Spray Application Unit trials have shown that drift increases dramatically at boom heights above 70 cm. Syngenta Trials to control wild oats with Axial resulted in a yield gain of 0.2 tonne/ ha when sprayed at 50 cm boom height v. 1.0m boom height. You will see many sprayers operating at boom heights greater than 1 m!! This will reduce the performance of the product. Modern sprayers are equipped with sophisticated boom leveling and suspension devices, but they must be working effectively to maintain even spray pattern and coverage – particularly on extra wide spray booms where stability is crucial. The suspension system needs to be maintained correctly, and tyre pressures should be the lowest recommended by the tyre manufacturer for the load to be carried. All sprayers should have a cable tie on the end of the boom set at 50 cm, so that operators can visually check the boom height in work.

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ERATOR OP

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Better rinsing of small necked bottles George Sargent The new container rinse devices are extremely effective, with a high flow of high energy water. A problem arises with small necked cans that the water enters faster than it can get out of the neck, the can fills up and absorbs the energy of the rinse water. George Sargent’s solution is to pulse the rinse water. 3 seconds on, 3 seconds off - 3 times, for an excellent rinse.

Agrochemical formulations and tank mixing A product is a combination of the active ingredient (ai), and added formulants to make it mix with water, wet leaf surfaces and improve the application characteristics. They also give the product a shelf life of at least two years. New operator friendly products are coming to the market all the time. Liquids have always been popular with spray operators, as they are easy to measure and pour. Some products may be formulated as solids for safety or environmental reasons. 18

Agrochemical formulations are often very complex. This is because they have to carry sophisticated organic chemicals in a way that maximises efficacy, allows safe handling and storage, does not harm the sprayer and is as safe as possible to the environment and water. Typically a formulation may contain a balance of emulsifiers, wetters, dispersing agents, thickeners, antifreeze and anti-foam agents that may have taken years to perfect. Therefore, it is important that the mixing and agitation instructions are carefully followed, for they affect both the ease of spraying and efficacy of a product.

Principal Formulation types Liquids

Solids WP - Wettable SL - Soluble Concentrate Powder WG - Water SC - Suspension Concentrate Dispersible Granule WSB - Water SE - Suspo Emulsion Soluble Bag EW - Oil in Water Emulsion EC Emulsifiable Concentrate

Handling techniques for different formulations Adding pesticides to the sprayer has become much easier since induction hoppers were introduced, but it is still important to follow any specific filling instructions carefully. Induction hoppers have greatly increased in efficiency

(suck) in the last 10 years. Unfortunately there are still some poor ones out there, with too small hoppers, and limited sucking power. Liquids should be added to the sprayer, by first partially filling the induction hopper with water, and adjusting the outflow, and the inflow of water to maintain a near constant level. Pour the chemical into the circulating liquid. The principal reason for doing this is to stop air being sucked into the sprayer, which will inevitably result in foaming. It also makes the hopper easier to rinse. High dose dispersible granules like Unix and Fubol Gold should be added dry. Fill the induction hopper before opening the valve. When it is opened the granules are sucked into the venturi and mixed with water on their way to the tank. Just before the granules have emptied from the hopper, the water flow should be turned on to rinse the hopper clean and to prevent air getting in to the tank. Low rate granule formulations, such as the sulphonyl-urea’s, are best added to water in the part filled hopper. Powders can also be added dry via the induction hopper in most sprayers. If this is not possible, they must be premixed and poured in through the filter basket like a liquid formulation. Products in water soluble packaging should be added via the induction hopper at a steady rate, similar to a liquid, using the water from the rinse ring to dissolve the film. Water soluble bags added through the tank lid should always be added to a 1/4 (not half) full tank since this gives a strong agitation and speeds up the mixing. If you are using a tank mix make sure that the water soluble packs go in first and are thoroughly mixed before adding other products otherwise the bag

may not dissolve. Turning on the tank rinse nozzles helps the dissolution of water soluble bags.

The benefits vs. risks of tank mixing Tank mixing allows complementary products to widen the range of ‘pest’ control, while one pass of the sprayer makes for more timely spraying, reduces costs and at the same time limits crop and soil damage. The risks of tank mixing include impaired efficacy due to antagonism - for instance mixing mecoprop with Axial will reduce grass weed control. There is also the potential for more crop scorch, as the amount of wetter in the mix increases with each product added; the addition of a BYDV spray increases the likelihood of herbicide scorch, for example. Lastly, and the most common problem is physical incompatibility, where the sprayer gets bunged up. Trace elements such as manganese and magnesium are notorious for blocking sprayers. Quality liquid formulations are less likely to cause problems than solids. Always read the labels for any instructions about tank mixing. You can do this out of season for the mixes that you know you are likely to use, and at the same time carry out your COSHH assessment to ensure there is no extra hazard for the operator. Many tank mixes are not ‘on the label’. Where Syngenta products are concerned a telephone call to Syngenta Technical Enquiries on 0800 169 6058 will tell you whether the intended mix is physically compatible or not. 19

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If instructions for tank mixing are not given on at least one of the product labels, the risk of unpleasant reactions can be limited by checking the formulation type shown on the label and filling following the sequence shown in the table below.

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On no account add two products to the induction hopper or sprayer at the same time. Always ensure that each product is well agitated in the tank before the next one is added.

Drilling and tramlining

Mobile Phone Hands free kit Iain Robertson A sprayer requires an incredibly high level of concentration to drive safely. But operators frequently have to be in communication with others to arrange a constant supply of clean water and product to maintain high outputs at busy times. Operators taking a mobile phone into the cab should have a hands-free kit.

Tank Mix sequence, where no order is given on the label

Solids

Liquids

Other 20

1 2 3 4 5 6 7 8 9 10 11 12

WG WSB WG WP SC SE EW EC SL

Water Dispersible Granules< 100g/ha Water Soluble Bags Water Dispersible Granules> 100g/ha Wettable Powders Compatibility Agent Suspension Concentrate Suspo-Emulsion Oil In Water Emulsion Emulsifiable Concentrate Soluble Concentrate Other Adjuvants Trace Elements/Foliar Feeds

The person who is going to do the spraying should either do the drilling or be closely involved with it since the lie of the land, setting up, the position of water courses, environmentally sensitive areas and irregular features such as telegraph poles, or wet or shaded patches can seriously disrupt spraying later in the season.

Identify watercourses and environmentally vulnerable areas. All water sensitive, Countryside Stewardship, SSSIâ&#x20AC;&#x2122;s and other vulnerable areas should be recorded on a farm map that can be kept with the operator and in the farm office. The plan is also useful in pre-season planning on how to use products that present a risk in such sites.

Local Environmental Risk Assessment for Pesticides (LERAP) Introduced in 1999, LERAPS are designed specifically to protect water course environments. Products are divided into Categories A, B and No LERAP. Products in category A (predominantly insecticides) are subjected to a 1m mandatory buffer zone, plus an additional 5m mandatory buffer zone, irrespective of the application technique.

In addition, water quality and temperature can make tank mix incompatibilities worse in some areas.

Looking after the basics

Collect the output from individual sprayer nozzles with an accurate measuring cylinder. Time the output very carefully, since you are looking for only very small variations. (Note: Dye has been used for demonstration purposes).

Products in category B (of which there are many), are subject to the same mandatory 5m + 1m buffer. However the 5m buffer may be reduced to as little as 1m, if the dose rate of the product is reduced, and/or at least 12m of LERAP approved 3 star nozzles are fitted to the spray boom, and operated according to their LERAP approval. The whole farm should be clearly mapped for the presence of water courses and dry ditches. It is the responsibility of the spray operator to know the location of water courses and to inspect ditches before application to ensure they are dry. It is necessary to know the LERAP category for each product. The LERAP rating of a product may be identified by an octagonal star on the front of the label.

LERAP Star Rated Nozzles To qualify for a LERAP Star rating nozzles are compared for their driftability against a 110-03 Fan Jet at 3 Bar Pressure. A nozzle with a 3 star rating is 75% less drifty than the fan jet. A 2 star rating is 50% less drifty. Important: Nozzles have their LERAP status awarded at a maximum pressure, boom height, and forward speed. Just fitting the nozzles does not comply with the conditions of LERAP.

Check product labels for critical application information Before the season starts check for application information on the labels of products likely to be used and be sure you can meet the requirements for storage, spray quality, recommended adjuvant, personal protective equipment, hazards to wildlife or livestock, withdrawal intervals, harvest intervals, etc.

Calibrate the sprayer All sprayers need calibrating. Although many sprayers are often now fitted with rate compensating systems that can be monitored in the cab, it is vital that their accuracy is regularly checked. The basic calibration procedure should be known by all sprayer operators. Speed of travel, nozzle flow rate and nozzle spacing, control the accuracy of spraying. The nozzle pressure needed to get the right flow rate must also give an acceptable spray quality. 1) Check the forward speed, by timing the sprayer over 100m: 360

Nozzle wear At the beginning of each season, and regularly during the season if you carry out a lot of spraying, check the flow rate of all your nozzle sets individually (See Nozzles page x). Also check overall wear of the nozzle set by keeping a new nozzle to one side when fitting a new set, to periodically place in the boom and cross check its output with the nozzles in use.

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Complete information on LERAPS is most easily obtained from the DEFRA website: www. pesticides.gov.uk/farmers/leraps-arable.htm.

Select the nozzle type that will produce the least drift, while maintaining efficacy.

Fit the appropriate type and size of nozzles,Set the sprayer running at your normal spray pressure and collect a timed 1 minute or half minute flow in a measuring cylinder. When using a measuring cylinder, be sure you hold it by the neck to check the reading. Jugs are a poor measuring vessel for nozzle flow rates, as the scale is too coarse and easy to misread. If using a jug (in the absence of a measuring cylinder), be sure you place it on a flat horizontal surface to read, otherwise you are likely to record the wrong figure.

A written farm LERAP policy should detail precisely the action required for different category products and be retained alongside the LERAP map. For record keeping, it is satisfactory to tick a box detailing that a LERAP assessment was made before spraying and that the farm policy was adhered to.

Select nozzles to minimise drift risk and achieve correct spray quality

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Using a marker pen to clearly highlight the category on the spray container will help avoid errors during busy times.

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Set Tyre Pressures Accurately Daniel Sharps Correct tyre inflation pressure is key to boom stability. The tyres are the principle shock absorbers of bumps up to 50 mm in diameter. Too soft you damage the tyre, too hard the boom deflects unnecessary. The optimum pressure is the minimum recommended pressure for the maximum load the tyre will be subjected too. The pressure can be found in the tyre manufacturerâ&#x20AC;&#x2122;s literature.

Check boom performance and tyre pressure

Calculate accurately the area to be sprayed

If the speed recorded on the spray monitor differs from the true speed, it means the wheel size needs recalibrating.

To perform at their best, booms must be level, and the boom suspension, dampers and joints regularly adjusted and lubricated.

2) Calculate the flow per nozzle required to apply the intended application rate:

In addition tyres of the tractor, trailed or self propelled unit are often run at too high a pressure to get the best out of the boom. Working at the lowest compromise to suit load carrying capacity, amount of road work, and boom stability, will often improve things. Take advice from the tyre manufacturer about the lowest safe pressure.

Mark up a farm map with accurate sprayed areas for all the fields and make a separate calculation of their headland area. This will help you when calculating a reduced dose to be applied on the area where tank washings will be sprayed out.

Sec. per 100 m

Application rate (l/ ha) x speed (km/h) x nozzle spacing (m) 600

= Speed Km/h

= Required l/min per nozzle

Consider the effect of dew, rain, wind and temperature on product performance

Rain stops play Avoid being rained off! Chemicals do not like being mixed with water for long periods of time. If the rain starts in earnest before you have emptied the tank, be prepared. First, decide if the delay is likely to be long or short term. If short term, the spray can be kept in the sprayer tank but it must be regularly agitated and if possible circulated around the sprayer. If this isn’t done severe problems may be caused by products settling out, separating, or damaging sprayer components.

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Spraying any product in bright sunlight can result in scorch. The risk of scorch is greatly reduced if spraying is avoided between the hours of 10.00 am and 3.00 pm.

Temperature has different effects on different products. Axial and Topik are effective at very low temperatures. The constraint is that below 10C ice forms on the spray tips and blocks them. Some Broad leaved weed killers, and PGRs may be ineffective at low temperatures, needing 80C before they are active. Moddus is less temperature sensitive than most other plant growth regulators

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Many products have a rain fastness time indicated on the label. This usually shows a worst case scenario and many products have an amazing resilience when there is dew present or a drizzle ensues. A heavy shower during or immediately after application is likely to be detrimental, however some moisture can be a positive advantage in helping to distribute the product over the leaf or improve its uptake.

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storage tank. This allows agitation of all the spray mix and it should be carried out at regular intervals, especially with tank mixes. When the weather clears the mix can be used to finish the job in hand. If the long delay means you miss the spraying window, the product will have to be used on another crop with an approval for use. If this is not possible, the only route is via an authorised waste disposal firm.

Avoiding contamination if the sprayer foams up when filling Andrew Goldring A sprayer overflowing when filling will suddenly deposit 50l of spray mix ion the ground in 10 seconds. To mitigate the risk of this happening, Andrew Goldring cut a 200l plastic drum in half, and slides it under his sprayer when filling, as an insurance policy. Although wettable powders will settle out, they are generally easy to stir up when agitation is resumed. On the other hand, emulsifiable concentrates are easy to mix at filling but can be difficult to mix up after they have been standing. Settling out in the booms is likely to be more of a problem with SC’s and WP’s, but EC’s may damage some types of diaphragm check valves. To overcome these problems boom re-circulation and boom washing facilities have been fitted to some sprayers in recent years.

How best to store spraymix if rained off and prepare for later use/disposal When rained off the best option is for the sprayer contents can be transferred to a bowser or

Avoiding waste Avoiding the problem starts with accurate monitoring of field sprayed areas to calculate the load size, and accurate measurement of liquid into the sprayer so that it is all used. The conventional sight gauge on a sprayer is often unreliable, especially on sloping ground and when using reduced water volumes. Sprayers fitted with a central tank float reading out on a dial or plumb bob fare better, but by far the best way is to use a flow meter fitted in the water filling line. This can also be automated to switch off or sound an alarm when the correct amount of water has been added. Overfilling with water creates the major risk of losses during filling – a high capacity pump at 600 l/min will push out 50 litres of spray mixture in 5 seconds. Foaming can also create a problem (See Handling Techniques page x).

Filling and pack rinsing procedure Sprayers can generally self fill with water, in less than 10 minutes. It takes considerably longer to add the chemical and rinse the containers. For recycling purposes containers must be well rinsed before disposal through collection. The less water there is in a sprayer, the greater the agitation. In fact agitation in a full sprayer is so poor that chemicals added late in the filling procedure may not be mixed when spraying commences. Trials have shown that rinsing containers with Spray mix is more effective than rinsing with clean water! With this in mind, the most effective way to fill the sprayer is as follows. 1/3 fill the sprayer with clean water, add the chemical, and rinse each container thoroughly with circulating spray mix. Put the ‘rinsed’ containers upright on the measuring table. When all the product has been added, continue filling the sprayer with clean water, and give each container a second thorough rinse with this filling water. The longer you leave the container to drain, the less liquid will be left on the inside. In my experience, most chemical spillages happen at the rinsing stage. The best practice is to place a plastic tray underneath the hopper, to collect any spillage, which can be poured back into the sprayer. When rinsing containers it is important to keep the pack moving up and down from neck to base of pack and rolling in a rapid movement for at least half a minute. This ensures that all nooks and crannies are cleaned out. A long blast can result in the container filling up with water, which greatly reduces the effectiveness of the blast from the 25

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rinse nozzle. Short, three second, pulses will do a better cleaning job than a long blast.

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Some pack rinsers also have a tent fitting that allows rinsing of foil packs. Where the chemical residue is particularly difficult to remove, the only way to effectively rinse the container is by part filling it with water, refitting the lid, and shaking. Take care when handling chemical concentrates. Accuracy in measuring out product is very important. A jug and scales of appropriate size need to be at hand. Measuring should be done at waist height, within a large container to catch any spillage. A filling table at induction bowl height large enough to carry a complete sprayer load, allows convenient and safe working. Since 2009 Syngenta packs have no foil seal, which greatly speeds up container handling as well as increasing safety. Where seals are fitted on other containers foil induction seals are best left partially attached to the top of the bottle. Avoid dropping the foil pack seals on the ground, as they may contain very small amounts of chemical concentrate. Removing some of the teeth from a foil cutter will enable bottles to be opened, but the foil remains in place and can be washed with the container.

Foaming Overfilling is probably the biggest single cause of pesticides finding their way into water. Foaming in the spray tank causes spray mix to leave via the overflow, before the sprayer is truly full.

Foam in the sprayer is best cured by the addition of an anti-foam, available from chemical suppliers. Keep some in the spray store for emergencies. An open 200l drum placed underneath the overflow pipe from the spray tanks is a good insurance against accidental overflow.

Reducing Packaging Waste What to do if your sprayer foams up while filling Danny Sole When a sprayer foams up, one is snookered, you can’t empty it because you don’t know the chemical strength, and you can’t fill it, because it will overflow. The solution is to follow the lead of Danny Sole, and always keep a pack of anti-foam handy at the filling site. The 3 most common causes of foaming are: 1. Leaving the induction hopper open; and sucking in air. 2. Air leaks in the pipework; Their presence is most easily detected by looking into the tank when circulating clean water. Any sign of bubbles even fizzy drink sized bubbles, means there is an air leak on the suction side of the sprayer. 3. Adding chemical when there is insufficient water in the sprayer; The circulating spraymix shoots upwards inside the tank, mixes with air, and creates foam.

Where available, buy products packed in returnable refillable containers such as the LinkPak. LinkPak, is purpose designed for agriculture, very safe to the operator, accurate for measuring small quantities, and yet can transfer 10l of product into a sprayer in less than 20 seconds. There is no need to rinse the empty container, which is returned to the supplier. When using conventional packs, where there is an option, choose the largest size available.

Similarly, as forward speed increases the spray swath creates its own turbulence, sucking the fine drops upwards which in turn exacerbates drift. In practical terms this means one should choose a forward speed and stick to it. Automatic rate controllers offer the opportunity to compensate for a reduction in speed when climbing hills. Another benefit they offer, is that operators can slow down and apply a coarser quality spray when spraying close to a sensitive area such as a pond or houses. Finally, the faster the forward speed of the sprayer, the less penetration you will tend to get in a cereal crop. This has been found to be detrimental to wild oat control. So when spraying a heavy wild oat infestation from GS 37 in the spring, it is recommended that for best control speed should not exceed 12km/h

Spray Drift

In the field The effect of speed on spray quality and trajectory The speed of travel can affect sprays in several ways. On sprayers fitted with automatic rate control, increasing speed, increases spray pressure by the square of the increase in speed. For a small increase in speed you need a large increase in pressure to maintain a constant application rate. So the spray becomes much finer and prone to drift.

Causes - and things that make it worse Wind: Double the wind speed and spray drift increases 2x Wind direction: Spraying into the wind is the same as increasing forward speed. Boom height: Double the boom height and spray drift increases 10x Increasing forward speed increases turbulence around the boom and therefore drift

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Sprayer Rinse tanks do not, as a rule, have a sight gauge, which makes accurate division of the contents into three equal volumes difficult. Steve Lake’s solution to this problem was to time the total transfer time of the rinse tank to the main tank - in his case 90 seconds – and divide the result by three. So to transfer 1/3 of the contents require 30 seconds, which he can now simply and reliably achieve each time. Bare Ground creates negligible downward air currents, so the spray drift will travel right across the field Zero wind is frequently associated with temperature inversion, where a layer of cool air is trapped below warm air. When this inversion occurs, spray drift gets trapped above the inversion layer and wanders off, sometimes for miles. Fine sprays drift more than coarse sprays, for any given nozzle type the smaller sizes will usually generate a higher % drift than larger sizes. 28

How to reduce spray drift Wind: Choose the right day and right time of day. Wind tends to drop in the early morning, and the evening. Check Agri-Cast on the Syngenta web site – www.syngenta-crop.co.uk - for predicted spray opportunities in your locality for the next five days. Boom Height: keep below 50 cm. All sprayers new and old should be fitted with a cable tie at the end of each boom cut to 50cm, so that the operator can keep a constant visual check on the boom height. If you are buying a new sprayer, make sure it is fitted with an automatic boom height adjuster. Speed: reducing speed reduces spray turbulence and spray pressure, so drift is reduced. At 2 bar there is appreciably less visual drift than at 3 Bar. Wind Direction: Spraying with the wind reduces drift. It is good practice when spraying near potentially sensitive areas, to spray with the wind, with the boom as low as possible, using the least ‘drifty nozzle option.

Managing waste Mark the point where a load runs out Do not waste spray by over spraying an already treated area because you may also exceed the maximum permitted dose and/or number of applications. Neither do you want unsprayed areas which can become weed or disease infested. You can identify the point where spray runs out by setting the position on the in-cab spray monitor or with a cane or other maker. If you use a marker take care not to walk in the sprayed crop and position it alongside the front wheel.

Washing out

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Dividing The Sprayer Rinse Tank into three equal parts Steve Lake

Nozzle choice: Use the most drift reducing nozzle recommended for the job. In arable crops there is a reduced drift option for all Syngenta products. The Amistar Nozzles, Defy Nozzles and Potato Nozzles, are all less drifty than their equivalent 1100 Fan Jets.

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Reducing water volume increases % drift, because smaller orifice nozzles are used. However, increasing water volume looks visually worse; whilst reducing % drift, there is more to see.

Plants: The more foliage the more eddies are produced which help suck the spray downwards. A tall crop reduces drift compared with zero crop. Similarly field margins reduce off target losses. The best thing for absorbing air movement is a ‘porous’ hedge. A solid wall is almost useless, The air is deflected over the top.

Similarly nozzles described as ‘Variable Pressure’ or ‘Extended Range’, which hold their fan pattern at lower pressures, will at a pressure of 3 Bar be more drifty than a conventional fan jet at the same pressure

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Spraying Warning Boards for footpaths Rob Cannell There is debate over the signing of footpaths before and after spraying a field with a footpath crossing it. Rob Cannell has a pragmatic approach. He carries 2 warning boards, one on each boom, stored in attached tubes. As he sprays the headland he gets out and places the boards at both ends of the footpath, when he has finished the field he collects in the boards in again. recommended label rate, in which instance it is good practice to rinse dilute spray onto a previously sprayed bit of field, without exceeding the maximum dose. If you are applying the spray at full rate, know the size of the last field to be sprayed, and underfill the sprayer to ensure that at least a 10% dose reduction is applied to an area where you can spray out the tank rinsings. This is often the last headland, but if high level of control is wanted here, another area can be reserved.

Plan the last load. Ensure last sprayed load allows tank rinsing water to be sprayed out Many products are applied at less than the 29

A wash down area can be designated on an Environment Agency approved piece of waste land which is appropriately fenced and signed. On a concrete yard washings should be collected in a central drainage tank and disposed of safely, by authorised disposal company. The Biobed is another option - a lined pit with a high humus filling and two wheeling tracks for the sprayer unit. Washing down is carried out over the bed and bioactivity in the humus inactivates and makes safe the pesticide residues. Information on building a biobed is available at www.voluntaryinitiative.org.uk

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Washing the outside of the sprayer is good practice. Many sprayers now come fitted with a washing lance, using clean water from the rinsing tank to clean the sprayer in the field. Washing a sprayer in the field has been shown to have no greater concentration of spray product than the spraying process itself. Take care when using high pressure jet cleaners to avoid damaging delicate sprayer parts or contamination from splash back.

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Washing down the sprayer

Triple rinsing does much to clean out the nozzle bodies, boom and line filters but they should all be thoroughly cleaned when changing products, especially when moving on to a sensitive crop.

Container disposal in the UK has to be via an approved waste disposal contractor. It is important that the containers are clean and dry. It is good practice to store rinsed containers with the lids off, as this ensures they are dry when taken off the farm.

Spraying Records The record book should be filled in as you leave the field. A good record system will fulfill all the basic management functions, and enable operators and agronomists to ascertain at a later date why a product performed particularly well, or badly, and give support in the event of a complaint by a member of the public.

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Cleaning booms, nozzles and filters.

Large farms with more than one operator are potentially vulnerable to sprays being missed, especially when there’s a crop like potatoes which may need spraying every week. Graham Crane’s solution is to have a cork board marked in days of the week, on the wall of the chemical store. This forewarns whoever is on spray duty, which fields need spraying on which day.

Where possible avoid the need for disposal by using returnable refillable containers, such as the LinkPak

If rinse tanks are not fitted they can often be retrofitted at reasonable cost, sometimes as a front mounted tank. Otherwise a small towed bowser of water taken out with the last load solves a disposal problem back at the yard.

Spray programmes Graham Crane

Disposal of empty containers

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Tank rinsing is always best carried out in the field. Sprayers with clean water rinse tanks and internal tank rinse nozzles make this easy. Tank cleaning additives help with this and are essential when using sulphonyl urea based products. In all cases triple rinsing should be used and a standing recirculation period used before the washings are sprayed out. Dividing the contents of the clean water tank into 3 equal small rinses, cleans the spray system 4 times more effectively than one big rinse.

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Rinse sprayer in the field.

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Looking after your PPE Nick Stevens All sprayers have a container on them for operator’s protective clothing. However, most of these get contaminated by drips and drift. Nick Stevens fitted a large container with a close fitting lid onto the front of his sprayer; it’s far away from the spray boom and drift, and it cannot be dripped upon.

Check that the spraying records cover all the information required by the ‘Green Code’. Include - Date - Time/s of start and Finish - Field name or number - Field area - Crop and Growth stage Products used - Product dose rates and quantities used - Application volume - Reason for spraying - Weather & soil conditions - PPE - LERAP - Harvest Interval - Re-entry: human and/or livestock - Sprayer operator - Bowser attendant (if any) and any other required by quality assurance schemes.

Guidelines for combinable crops 2010 Crop

Notes

Timing

Water volume (l/ha)

Forward speed

Best nozzle

Reduced drift option

Pre-em Herbicides

100 and above

12–16 km/hr

DEFY nozzle alternating forwards and back

AMISTAR nozzles

Post-em Herbicides

100 and above

12–16 km/hr

DEFY nozzle or HAWK nozzle all forwards or alternating forwards and back*

DEFY nozzles (worst case AMISTAR nozzles)

Spring Wild

Oats 100 and above

12–16 km/hr (slow down to 12 km/ hr for later season Wild Oats)

Standard Flat Fan or AMISTAR nozzles (keep to 50cm boom height)**

AMISTAR nozzles

All fungicides T0–T3

100

12–16 km/hr

AMISTAR nozzles

Pre-em Herbicides

100 and above

12–16 km/hr

DEFY nozzle alternating forwards and back

AMISTAR nozzles

Post-em Herbicides

100 and above

12–16 km/hr

DEFY or HAWK nozzle alternating forwards and back

DEFY nozzles (worst case AMISTAR nozzles)

All fungicides

100 and above

12–16 km/hr

AMISTAR nozzles

AMISTAR nozzles AMISTAR nozzles

Cereals

OSR

Beans

Peas

Pre-em Herbicides

100 and above

12–14 km/hr

DEFY nozzle alternating forwards and back

Post-em Herbicides

100 and above

12–14 km/hr

DEFY or HAWK nozzle alternating forwards and back

DEFY nozzles (worst case AMISTAR nozzles)

Fungicides

100 and above

12–14 km/hr

AMISTAR nozzles or a standard flat fan

AMISTAR nozzles

Pre-em Herbicides

100 and above

12–14 km/hr

DEFY nozzle alternating forwards and back

AMISTAR nozzles

Post-em Herbicides

100 and above

12–14 km/hr

DEFY or HAWK nozzle alternating forwards and back

DEFY nozzles (worst case AMISTAR nozzles)

Fungicides

200

12–14 km/hr

Syngenta potato nozzle alternating forwards and back

Worst case AMISTAR nozzles

Pre-em Herbicides

100 and above

12–16 km/hr

DEFY nozzle alternating forwards and back***

AMISTAR nozzles

Post-em Herbicides

100 and above

Maize

12–16 km/hr (slow DEFY nozzle or Potato down for heavily nozzle alternating shaded weeds) forwards and back***

Potato nozzles

NOTE: To reduce drift slow down and lower the booms. *Nozzles should be forward and backward if ground conditions are uneven. **With AXIAL for volumes less than 200 l/ha use a minimum of 1 l/ha ADIGOR, 1 litre ADIGOR in 100 l/ha, 1.25 litres ADIGOR in 125 l/ha and 1.5 33 litres ADIGOR in 150 l/ha. ***DEFY nozzle preferred (03, 035, 04), but for higher volumes an 05 potato nozzle maybe required.

Syngenta Crop Protection UK Ltd. Registered in England, No. 849037. CPC4, Capital Park, Fulbourn, Cambridge, CB21 5XE. Email: customer.services@syngenta.com Web: www. greencast.co.uk / www.greencast.ie The Scotts Company. Tel: 08712 205353 Email: prof.sales@scotts.com Web: www.scottsprofessional.co.uk Banner Maxx® contains propiconazole (Mapp 13167, Pcs 02715), Heritage Maxx® contains azoxystrobin (Mapp 14787), Instrata® contains chlorothalonil, propiconazole and fludioxonil (Mapp 14154), Primo Maxx® contains trinexapac-ethyl (Mapp 13374, Pcs 02273). Banner Maxx®, Heritage Maxx® Instrata® and Primo Maxx® are registered trademarks of a Syngenta Group Company. All other brand names used are trademarks of other manufacturers in which proprietary rights may exist. Always read the label. Use pesticides safely. ©Syngenta AG May 2010. GQ 01020. Distributed in the UK by Scotts Professional