Timing and precision are vital for e ective and safe weed control

Timing and precision is vital for e ective and safe weed control

E ective grassweed control is essential in rotations with autumn-sown crops. Although product labels and technical support provide guidance on how to optimise herbicide e ectiveness in speci c situations, the general principles o ered below by AHDB apply to all crops.

Herbicides form a large part, typically 20–30%, of the variable costs associated with producing a crop. With the need to consider herbicide-resistance risks too, it is important to target each spray required.

Spray timing and herbicide resistance

Key annual grassweed species at risk from herbicide resistance include black-grass and Italian ryegrass. When applying glyphosate prior to drilling a crop, maximise e cacy (to reduce the number of survivors); always aim to: • Use the manufacturer’s recommended dose rate for the weed sizes present* • Apply prior to ‘shading’ from other plants • Apply to actively growing plants in warm conditions (15–25°C), with at least six hours before any rainfall. *Small weeds are particularly challenging targets, especially grass weeds because of their vertical structure. Ideally, spray when plants are at least 5cm but before the start of rapid stem extension.

It’s important to note that reduced glyphosate doses increase the risk of lower e cacy. Typically, annual grasses require a minimum of: • 540g a.i./ha for seedlings up to 2–3 leaves • 720g a.i./ha when tillering • 1,080g a.i./ha when owering. For full guidance visit https://ahdb. org.uk/knowledge-library/how-tominimise-glyphosate-resistancerisks-in-grass-weeds

Autumn-sown cereals

Mixtures (several products applied together) or sequencing/stacking (several products applied in close succession) are more e ective at controlling grass weed populations than individual products. Preemergence options are less a ected by resistance and should form a key part of a cereal herbicide programme.

Oilseed rape herbicides

Spring herbicide options are limited in oilseed rape and weed control decisions need to be made prior to drilling. Establishment methods and weeds present a ect control options: • Where shepherd’s purse and/ or cleavers are predicted, a robust pre-emergence treatment – based on metazachlor – is required. Rapeseed must be well covered by soil to a depth of 15mm • For black-grass and other grassweeds, herbicides such as propyzamide are more e ective after no or very shallow cultivation. Where deeper cultivations are used, adding a graminicide (‘fop’ or ‘dim’) will improve the level of control.

Droplet size and spray deposits

The highest deposits on target weeds result from reducing both application volume and droplet size.

Using lower volumes (around 100–150-litres/ha) is generally more e ective than volumes of 200-litres/ ha and higher.

Reducing water volume from 200–100-litres/ha, achieved by changing nozzle size, gives an estimated 40% increase in work rate for a 24m boom on a 3,000-litre, selfpropelled sprayer.

Increases in work rate can also be achieved by increasing forward speed and boom width. However, faster forward speeds and wider booms may require increased boom height. This increases the risk of drift, as does spraying reduced volumes through smaller-sized, conventional nozzles.

Some horizontal movement of droplets is necessary to ensure adequate deposition on small grass weeds. Angling nozzles is one way to create horizontal velocities, which increases active ingredient deposition on small vertical targets.

For many herbicides, nerquality sprays are more reliable than coarser sprays. Often, air-induction nozzles giving the smallest droplet sizes perform as well as medium- ne conventional sprays.

Larger weeds are more suitable for treatment with air-induction nozzles, particularly those giving the smallest droplet sizes, which can still signi cantly reduce drift compared with conventional nozzles.

Controlling drift

Where conditions limit available spray days, high work rates are necessary but must be balanced against the risk of spray drift. Increased drift is associated with: • Fine sprays • Applications to small canopies • Increased boom heights • Higher wind speeds • Particular formulations*. *Water-soluble liquid formulations with a high level of surfactants – such as glyphosate – may also increase spray drift, so additional precautions for controlling drift may be necessary.

It is essential to comply with product labels and the Code of Practice for using plant protection products.

It is important to keep pesticides out of watercourses.

Water quality legislation may a ect or restrict use of several herbicides, particularly those used extensively, as well as those used at high rates and applied at times of year when drains may be running or there is potential for run-o to watercourses.

The result of new legislation could be restrictions on rate and/or timing, with product withdrawal as a last resort.

The Voluntary Initiative provides best-practice guidance for the main pesticides that pose a particular concern to water. For more information visit https:// voluntaryinitiative.org.uk/resources/ wpas/ FG

Weed challenge Nozzle style and droplet size

Air induction Conventional

Small Large Fine Medium Coarse

Pre- and post-emergence *

Grassweeds – 3 leaves or fewer

Grassweeds – more than 3 leaves

Broad-leaved weeds – up to 2cm across

Broad-leaved weeds – 2–5cm across

Broad-leaved weeds – more than 5cm

Non-selective (e.g. glyphosate) * Drift control

* Drift control ** Drift control * Drift control

* Drift control * Drift control

** Drift control

British-built sprayer range continues to grow

British-based sprayer company Team Sprayers has been manufacturing sprayers at its Ely factory for over 40 years, and its agricultural range includes both tractor-mounted and trailed sprayers.

The company’s bestsellers continue to be the trailed Leader range, featuring both the Leader 3 and Leader 4 sprayers (pictured).

Team managing director, Danny Hubbard, said: “It’s been a very busy year for us, particularly on the Leader range. All our sprayers are built to order and we are currently working on lead times of 4–5 months for one of our larger models such as the Leader or Arian, depending on the level of technology required. I would encourage anyone who is thinking about changing their machine for next spring to get in touch soon, so we can discuss requirements.”

The Leader 3 comes with boom widths up to 32m, and tanks up to 4,000 litres, whilst the larger Leader 4 sprayer goes from a 24–36m boom with tank sizes up to 5,000 litres. Both models feature boom stabilisation and computerised boom switching, with GPS and steering options. They also feature electro-hydraulics enabling boom folding combinations while self-levelling tilt and anti yaw mechanisms increases boom stability and application accuracy. Variable boom geometry and computerised spray rate control are also available as optional extras. The Leader 4 model also incorporates a low-folding boom design which, along with the pro led tank gives the sprayer a low centre of gravity and maximises machine stability either in eld or on the road. FG

The Arian 2 Mounted Sprayer

Effective, Accurate Controlled.

The new Arian 2 Sprayer comes in 1200L, 1600L and 1800L tank sizes.

The boom is very compact when folded away, which is great for us as we move around a lot between farms. It’s brilliant in the field and very easy to operate. I have been “ really pleased with it and wouldn’t hesitate to recommend it.

TONY LEACH, TONY LEACH CONTRACTING SERVICES

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For further information, please get in touch. team-sprayers.com • 01353 661211

Nutrient e iciency biostimulant approved for organic use

Corteva Agriscience’s nutrient e ciency biostimulant Utrisha N has been granted organic certi cation following its launch in the UK and Ireland this year.

Certi cation from Organic Farmers and Growers (OF&G) means Utrisha N is now approved for use on organic farms and can be used on cereals, OSR, peas and beans and grain maize.

Utrisha N is an alternative nitrogen source that can supply actively growing plants with additional nitrogen to facilitate plant growth.

This breakthrough technology adapts to plants’ growth needs, helping to sustainably maximise crop yield potential.

Clare Stapley, biostimulants product manager for Corteva UK & Ireland, said: “We are very excited to have been granted organic certi cation for Utrisha N with Organic Farmers and Growers (OF&G) and to be able to o er organic farmers a product that can deliver a supplemental source of nitrogen.

“Utrisha N is a novel nutrient e ciency biostimulant that enables plants to x nitrogen from the air and make it available to the plant. “With the cost of nitrogen soaring, an alternative source is vital and it’s great that we can now o er organic farmers the option to incorporate Utrisha N into their fertiliser plans for next year and produce food using a sustainable product.”

Utrisha N is foliar-applied with a wide window of application and should be applied at a rate of 333g/ ha and when the crop is actively growing, at a temperature between 10–30ºC. Applying early in the morning when the stomata are open and there is good soil coverage will ensure its e ectiveness.

Utrisha N is available to order via crop production specialist Hutchinsons. FG

BTS 3610

DESIRABLE ALL-ROUND PERFORMER

High adjusted tonnes: 101.6 % High sugar content: 17.3 % Good ESB and NSB characteristics

NEW

BTS 3020

THE EARLY BIRD

For the earlier sowing opportunity High adjusted tonnes 100.1 % Excellent ESB and NSB characteristics

BETASEED. SIMPLY DIFFERENT.

Limagrain UK Ltd Rothwell, Market Rasen, Lincolnshire, LN7 6DT Tel : 01472 371471 Fax : 01472 371386 Enquiries@limagrain.co.uk www.lgseeds.co.uk/sugarbeet www.betaseed.uk

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