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Scroll down to find out information on how to optimise applications of Prevail Pro. Alternatively, download the information in PDF format here.
Product performance
Prevail®Pro contains clopyralid and halauxifen-methyl (Arylex active). This new formulation gives outstanding control of creeping thistles*, buttercups** and dandelions. Use on established grassland for grazing only. Once applied, it translocates down into the roots securing good plant kill.
Prevail Pro will not kill nettles or ragwort but will kill clover if present.
Application timing for optimal control
For optimal effect, leaf area, leaf health and active growth are key. Spray when weeds are 150 to 300 mm in size.
Maximising the efficacy on thistles
For optimal effect, leaf area, leaf health and active growth are key. Application should be made when weeds are actively growing and are 150 to 300 mm in size.
The following factors can limit the actual level of control achieved:
- Spraying too soon after topping - leaves are too small relative to the size of roots.
- Spraying thistles that have started to flower or thistles with many older leaves that lack active growth.
- Too many thistles may shade some, preventing targeting of spray. Shading by an excessive amount of grass will also have an effect.
Topping and spraying thistle re-growth once it reaches optimal size improves the levels of control if these factors are present.
This practice ensures all plants are of a similar size with leaves that are free from disease and damage. Note that if topping in July and growth is slow, then there may be insufficient re-growth to spray before the end of the application window which is 31st July.
Prevail Pro also controls hogweed and cow parsley.
Other key weeds
Target buttercups and dandelions that show good leaf visibility whether pre-flowering or flowering. When in flower, spray early in the morning or late evening, when less pollinators are present.
Grass treated with Prevail Pro must not be cut for fresh grass, hay haylage or silage within 12 months of treatment.
*Spear thistle (also called a Bull Thistle) and Marsh Thistle are also controlled.
**Both creeping and meadow buttercups are controlled.
How to optimise Prevail Pro application using drift reducing technology
Air inclusion nozzles are possibly the best for reducing drift by creating larger droplets containing small bubbles of air. This coarser droplet enables the spray to travel accurately from nozzle to target. On impact, the droplet bursts leaving small droplets across the leaf surface. This leads to less drift and more deposit of product on to the target leaf.
Travelling speed and water volume will determine the exact type of nozzle to use. Prevail Pro must be applied in 200-400 litres water/hectare.
The table below provides a list of nozzles which are options based on the parameters described above:
| Billericay Farm Services (3 bar) | Lechler (3 bar) | Hardi (3 bar) | Teejet (2 to 4 bar) |
|---|---|---|---|
| Air Bubblejet 03 | IDKN 120-03 | Minidrift (MD) 04 | AIXR 110 4 |
| Air Bubblejet 04 | IDKN 120-025 | Minidrift Duo (MDD) 04 | AITTJ 60 110 03 |
| Air Bubblejet 05 | IDKN 120-03 | AITTJ 60 110 04 | |
| BFS PulZar 04 | IDKN 120-04 | ||
| BFS PulZar 05 | IDKN 120-05 |
Manure management
- DO NOT use Prevail®Pro on grass that will be cut for animal feed (i.e. fresh cut grass, silage, hay or haylage) as herbicide residues will carry over into the forage and unwanted growth effects can result if this manure is applied to sensitive crops like potatoes or tomatoes in a green house. The graphic shows the do’s and don’ts.
- Treated grass must not be cut for animal feed (i.e. fresh cut grass, silage, hay or haylage) in the same calendar year of treatment.
- Animal feed (i.e. fresh cut grass, silage, hay or haylage) produced from the treated area after an interval of 12 months, must stay on farm and manure from animals fed on this must stay on farm and be spread only onto agricultural grassland.
- DO NOT apply to flower-rich grassland. Cattle and sheep which have grazed Prevail Pro treated grassland must graze non-Prevail Pro treated grassland for 3 days prior to grazing flower rich grassland.
