The management of weeds, pests and diseases is a specialist area of turf care but there are some basics you can follow.
Pesticides can be harmful to operators, users, and the environment. The use of pesticides is regulated in law and requires specialist storage, application and disposal – you should only use pesticides if you can comply with this law. For occasional use you should use a specialist contractor who will be responsible for complying with pesticide law. This will help to reduce the risk of harm to you, the users of your facility and the environment. Always follow the label instructions and do not apply pesticides illegally. If you use pesticides on your ground (even where they are being applied by a contractor), you may need to register the site as a Plant Protection Product user with DEFRA. https://www.gov.uk/government/publications/professional-plant-protection-products-ppps-register-as-a-user
Controlling pests
Earthworms on outfields are less of a problem than on cricket squares but high populations of earthworms in clayey outfield soils can cause problems with casting and smears.
Remember that the earthworms are engineering the soil creating better drainage and aeration, so it is often better to manage the earthworm casts with brushing and frequent mowing than it is to try and control earthworms – furthermore there are no licensed pesticides for earthworm control in sports turf in the UK.
Worm activity is highest in Spring and Autumn, in Summer it is often too dry, but they will appear following rainfall. Note that chemical control of worms is restricted. Making sure you remove clippings and thatch to remove food for the worms and also remove worm casts before mowing help with this problem.
Other pests
Other pests you might see in your outfield profile are ‘Leatherjackets’ (the pupae of the crane fly) or ‘Chafer Grubs’ the larvae stage of chafer beetles. Getting rid of a grub problem can be very expensive and difficult, so cultural controls such as removing thatch are the best way to prevent an infestation.
Other pests affecting outfield tend to be larger whether that is birds pecking to remove worms, grubs and ants from the profile or rabbits, foxes and badgers digging – particularly in sandy or newly drained outfields. Control of these pests often involves bird scarers and fences as deterrents. If problems persist speak to your local pest controller but note that some species such as the badger are protected in law. Always repair any damage to outfield levels using a suitable divot mix of soil and seed. This is to reduce the risk of injury from a player getting their foot caught in the hole. Be aware that the animal is likely to dig out your repair (it is easier digging than the surrounding soil), in which case you can use a germination sheet to cover it, prevent damage, and encourage faster grass regrowth.
Dog fouling is a persistent problem in amenity areas and particularly on grounds were there is open public access. Always check for dog (and other animal) faeces and remove these safely. This is because as well as being unsightly, smelly and unwelcome by all, there are parasites present in faeces that can cause blindness and other illnesses in humans.
Weeds
Excessive weed content is unsightly, can affect outfield performance and will reduce wear resistance. The first line of defence against weeds is good cultural practice – making sure that the grass is not nutrient stressed, aerating frequently and keeping on top of hand weeding. As long as there is an over-seeding and fertiliser programme in place, winter se of outfields by junior football and rugby can be of benefit as this tends to wear out weeds, which can be replaced by desirable grasses if overseeded and goal mouths are repaired.
At the outfield scale, it can be harder to manage weeds by hand, but this practice is still encouraged to limit the use of herbicides. Using a knife, flat bladed screwdriver or peeler-knife, walk the outfield removing the weeds and plugging with loam and seeding to encourage grass to grow in the space left by the weed.
Where weeds are more widespread, persistent, or otherwise difficult to control by hand weeding, then use of a selective herbicide may be beneficial but before resorting to chemical control you should identify the weed using freely available turf management apps and see whether there is a cultural control such as adjusting nutrients, verticutting, aeration or mowing heights.
For example the broad leaved weed plantains (such as Plantago major) are often associated with compacted soils (their large taproot is more effective than grass roots in compacted soil) – so aerate the outfield. Some weeds such as clover are more common in outfields that do not receive regular fertiliser (the clover plant is better adapted than grass to low nitrogen soils but is less wear resistant).
If you are applying a selective herbicide – make sure that the herbicide controls the weeds on your square and only apply as a last resort. You must comply with all pesticide legislation and best practice guidance. If you do not have the correct storage, equipment and training then you should use a suitable contractor.
Disease
You should not need to apply fungicide as a preventative (technically called prophylactic application) because there are a number of cultural practices you can carry out to reduce disease risk:
- Fungal diseases like moist conditions so regular brushing of your grass to remove dew and get air to flow to the base of the plant can reduce disease risk.
- Keeping your mower sharp and setting it correctly to provide a clean cut of the grass is vital to reduce disease risk – ripped or torn leaves caused by a blunt or improperly set mower create weaknesses in the grass plant that fungal diseases can attack.
- Get your plant nutrition right when you use fertiliser. Red thread disease (Laetisaria fuciformis) is a common disease caused by low nutrient availability – you can control the early onset of red thread by applying a nitrogen containing fertiliser and then cutting to remove old leaves. Whereas Microdochium patch (Microdochium nivale, formerly called fusarium patch) likes lush, over fed grass in cooler temperatures which is why autumn fertilisers are lower in nitrogen.
If you do need to apply a fungicide always comply with the product label and use a suitably qualified contractor to provide advice and or apply the product unless you can comply with the relevant pesticide legislation.
Benefits
- Keeping on top of weeds, pests and diseases maintains a healthy sward that will lead to better performing, safer and more easily managed outfields.
- It also improves aesthetics, but this should not be the primary driver for application of pesticides.
Practical tips
- Good cultural practices can help prevent weeds, pests and diseases and help to protect the environment.
- Always follow the product label and comply with pesticide regulations. Full compliance with the legislation requires the correct storage, application equipment, personal protective equipment (PPE), wash down facilities, disposal and training – this can be prohibitively expensive to maintain for occasional use – so use a suitably qualified contractor who can comply with the law.
- Check to see if you need to register with DEFRA as a Plant Protection Product user.
- If you are unsure, speak to other grounds managers or your County Pitch Advisor.
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