Wimbledon is with us once again - hasn't that year gone quickly? Demand for courts will be high, although the unsettled weather for the start of July may just delay that a little.
As we move into the month, it is very likely that drier, warmer weather will be here and evapotranspiration rates will be high; water losses in July can be between 4-6mm a day. Irrigate uniformly and ensure you replace what has been lost. It is important to ensure that the water gets deep into the rootzone, to a minimum of 150mm to encourage deep rooting. Check with a probe. Allow to dry out and repeat the irrigation process.
Allowing surfaces to remain dry for a period of time can lead to problems of dry patch, a condition that prevents water infiltration into the soil and thus forming areas of non-uniform turf quality. To help overcome dry patch, the use of wetting agents have now become an integral part of the maintenance regime, with applications being applied on a monthly basis throughout the summer.
Key Tasks for July
This month sees the continuation of regular maintenance tasks - grass cutting, grooming, brushing, aerating, feeding and watering. Particular attention should be made to your irrigation regimes, ensuring that all turf surfaces receive adequate amounts of water to maintain growth.
Groundstaff will also be trying to maintain the sward height at between 6-10mm, depending on the level of play.
The condition of the court will certainly contribute to how well it performs, particularly with reference to ball bounce and foot adhesion. Ideally, you should be providing a true, firm and level surface that is both safe for the player whilst, at the same time, providing an adequate consistent ball bounce.
Foot traction/ball bounce can be affected by several factors:-
- Amount of organic matter (thatch) present in the surface
- Moisture content of the playing surface
- Condition of sward
- Insufficient court rolling
- Uneven levels/worn areas
- Type of footwear worn and condition of balls
Excess thatch content (more than 8mm) will affect playing quality by the mere fact that it becomes a spongy layer. This spongy layer deadens ball bounce and can cause poor foot traction - no grip. Control the build up of thatch by regular verticutting/grooming.
The level of moisture on or in the soil profile will affect how the court plays; a wet, firm surface will, in fact, speed up the pace of the ball. The use of covers will help control the wetness and condition of your courts.
The amount of grass cover on your courts will also dictate how the courts play. Too much grass, especially if over 10mm in length and over fed (applying too much nitrogen fertiliser) will, in turn, affect ball bounce and foot traction.
Other tasks include:
- Roll the courts to firm them up; rolling should be done during favourable weather conditions, ideally when the soil profile is malleable/moist enough to bind together.
- Monitor the condition of the court and constantly repair any bare and uneven levels. Topdress with compatible loam soils/ rootzone materials and overseed with a good quality ryegrass at a rate of 35-40 grams per m2.
- Ensure players are aware it’s their responsibility to ensure they’re wearing appropriate footwear and using balls that are not damaged.
Mowing. The mowing height on the courts should be lowered to around 6-10mm for the playing season, subject to local weather conditions, but remember not to remove more than 1/3 of total grass height in each cut.
Mowing frequency will be dependent on a number of factors, grass growth, sward type, level or standard of facility, resources (staff and machinery) but, generally, it may vary from daily, in the case of Wimbledon, to two to three days a week, or even weekly, depending on resources available.
It is important to remove any weeds from the playing surface, as they can affect ball bounce and performance of the court. Weeds can be removed by hand, or controlled by application of chemicals, usually a broadleaf selective weed killer. Best results are achieved when the soil has warmed up and the grass is actively growing.
Grooming and verticutting are operations that remove unwanted side grass growth and reduce the amount of debris in the sward. These operations are carried out on a regular basis, often weekly or fortnightly, and providing you have sufficient watering facilities. These operations are completed in conjunction with your mowing regimes.
Aeration. A programme of aeration can be considered to alleviate any compaction from recent play. However, this needs to be done with an appropriate aerator, something like the Hydrajet, Dryject or SISIS Javelin Aeraid, which are able to penetrate the hard clay soil profiles without causing surface disruption, thus allowing some much needed air exchange to promote a second phase of grass growth.
Irrigation. It is essential to have water available for irrigation purposes. Irrigation is required for court preparation and repairs. Ensure that the water gets down into the rootzone, a minimum of 150mm, to encourage deep rooting. Check with a probe.
Fertiliser. Fertiliser treatment and turf tonic can be continued in accordance with your annual programme. If you haven't got a fertiliser programme, have your soil tested; try an independent soil analysis company for an impartial set of results.
In recent years, we have seen a change in feeding habits in professional sport, with more groundsmen resorting to a more detailed feeding programme using a concoction of fertiliser products and soil conditioners to maintain plant health.
These products come in both granular and liquid formulations, Liquids formulations tend to be more efficient and react much quicker than granular products. However, granular products tend to be easier to apply and use.
We are now seeing granular products being used as base/slow release feeds and being topped up with a range of liquid feeds that include bio stimulants along with micro nutrients. To help improve the performance of these feeds, a number of soil additive products and wetting agents are in regular use.
However, for a majority of smaller clubs/facilities they will be reliant on a trusted base fertiliser, a 12:0:9, 7:0:7 or similar compound blend, or apply a slow release fertiliser to see you through to August. The choice of material and how well it works will be dependent on factors such as soil type and weather, with moisture and soil temperature being the catalyst for growth.
The performance of slow release fertilisers can be influenced by the weather, often producing a flush of growth when you least expect it. Some grounds managers may use straight compound granular or liquid fert
ilisers which activate when in contact with moist soil conditions, effectively stimulating grass growth within days.
Marking is important. Lines need to be clean, straight and accurate; ensure your marking machine is cleaned and serviced, checking that all the components are working properly. There is nothing worse than using a marker that drips and produces poor line quality. It will reflect on your workmanship. Remember to use string lines for accuracy. Also invest in a good quality paint products, there are plenty to choose from that will suit your requirements and budget.
As the climate lurches from blazing sunshine, intense heat and high evapotranspiration to low light levels, high humidity and potential waterlogging, so the plant is exposed to abiotic (environmental) stress one week and biotic (organism) induced stress the next.
Accordingly, a turf surface may enter wilt and dormancy one week or it may come under attack from fungal diseases the next. The key thing to understand is this; as the extremes are more intense and unpredictable, the buffer zone of tolerance before the onset of plant, and ergo surface damage, comes under increasing pressure. Turf surfaces which do not conform to good agronomic standards and are not being maintained with sound agronomic principles will have a very narrow buffer zone of tolerance, and will be toppled over the edge into damage far quicker than those which are.
So, theory aside, what practical steps can turf managers take through throughout July to help mitigate against stress damage?
- Use weather windows wisely
Time waits for no man and the British weather is no exception. Make sure you have stocks of feed and treatment on the shelf; in this way, you can make applications at the very best time to maximise positive effect on the plant and soil ecosystem, thus maximising turf quality and value for money.
- Monitor climactic patterns and gain an awareness of triggers
5-7 day forecast is hot and sunny – foliar apply seaweed to trigger plant systemic-acquired resistance mechanisms, tank mix with a little potassium to better regulate stomatal function and thus water loss, add a little calcium to compensate for its lack of mobility in dry conditions by shortcutting it straight into the plant where it can be utilised for the growth of cells.
5-7 day forecast is warm and humid – foliar apply some seaweed and a carbon sugar, again to trigger plant systemic-acquired resistance but also to boost plant beneficial rhizobacteria in the soil, add some phosphite and calcium to guard against fungal pathogen penetration of the leaf.
The key factor for determining success with these strategies is three fold: Monitor the upcoming climate > Understand what the prevailing climate will trigger > Understand the mechanisms by which products have an effect on the plant and in the soil.
The number one rule which applies to both - undertake these operations proactively prior to the stress, aim to prevent not cure.
- Look after the physics
Coming into or out of a wet period – soft ground means opportunity for deeper vertical aeration which will allow the soil to breathe assisting soil microorganisms and encourage deeper vertical rooting, increasing the plant’s tolerance to dry periods.
Coming into or experiencing a hot period – undertake sarel or star tine aeration to break through a high percentage of the soil surface, increase the ability of irrigation or water to penetrate, thus increasing the surface’s tolerance to dry periods.
General agronomic jobs for July
- Maintain wetting agent programmes.
- Maintain plant growth inhibitor programmes.
- As a rule of thumb, apply granular feeds when rain is prevalent and look more toward foliar or liquids when experiencing dry spells.
- Don’t apply herbicides when experiencing hot weather, as the plant will have shut down its systems, massively reducing uptake, transportation and thus efficacy.
- Continue to monitor the life cycle of insect pathogens such as leatherjacket and chafer beetles in readiness to apply entomopathogenic nematodes, as per the seasonal application periods.
- Monitor for anthracnose activity - the spores will have been activated by high temperatures at the end of the May and again the end of June, incubation takes around 6 weeks. Chemical treatments are an option, as are weekly small doses of nitrogen.
Recently, we have seen incidences of turf diseases such as Microdochium nivale (fusarium). Fairy Rings are in evidence and Red Thread has swept spectacularly through a lot of outfield turf. With such a peak in disease activity in mid-summer we are expecting continued problems over the next few months; therefore acting preventatively by applying a systemic fungicide such as Heritage Maxx will be the most effective form of control. Application before symptoms are visible but the threat is imminent is the key to success when adopting a preventative approach.
Symptoms of Fusarium (Microdochium nival), the most common and damaging disease, are orange/brown patches 2.5-5cm across increasing in size under suitable conditions as the disease progresses. Active patches have a distinctive 'ginger' appearance when viewed early in the morning. Creamy white mycelium resembling cotton wool can be seen in the centre and towards the outer edge of the patch.
Grass in the active patches is often slimy; once the disease is controlled the scars will remain until there is sufficient grass growth to fill in. Regular brushing, switching or drag matting in the mornings to remove the dew from the playing surfaces will reduce the likelihood of disease outbreak.
Red Thread is ill-defined bleached grass with Pink mycelium visible in early morning dew. Close inspection will reveal red needle like structures which are attached to the leaf blades. The needles become brittle upon death and are easily detached allowing fragments to spread the disease.
Systemic curatives and protective fungicides such as Chlorothalonil and Iprodione, applied in liquid form with water as a carrier, can be used to control any outbreaks. Mixing two or more products in the same tank can help reduce the potential for disease resistance developing. Fungicides are selected with different modes of action so that resulting mixture will attack the target disease on two or more fronts. This makes it more difficult for the pathogens to develop resistance to treatments.
It is important to remove any weeds from the playing surface as they can affect ball bounce and performance of the court. Weeds can be removed by hand or controlled by the application of chemicals, usually a broadleaf selective weed killer. Best results are achieved when the soil has warmed up and the grass is actively growing.
Please note: More information on these and many others can be found here: www.pitchcare.com/useful/diseases.php
It is important to keep you mowers clean and sharpened, adjusting/checking your height of cut on a daily basis.
Pitchcare provide a range of courses suitable for tennis clubs. In most cases, the courses can be held on site using the club's own equipment and machinery.
Some of the courses available are:
- Chainsaws - CS30 and CS31
- H&S Refresher Training on Combined Turf Care Equipment; Tractors and Trailers; All Mowers (Ride-on and Pedestrian)
- Machinery Courses on ATVs; Tractors: Brushcutters/Strimmers; Mowers (ride-on and Pedestrian)
- Pesticide Application (PA courses)
- Stem Injection of Invasive Species (Japanese Knotweed etc.)
- Basic Trees Survey and Inspection
Begin to plan your end of season renovations based on the condition of the courts. You may need to book specialist supplies and contractor services. Ensure you buy compatible loam/soil dressings for your courts.
It is essential to have water available for irrigation purposes. Irrigation is required for court preparation and repairs.
Seeding sparse or bare areas can be continued. Any rise in soil or air temperatures will help germination. Use germination sheets to aid this process but remove the sheets regularly to check for disease. Remember that without good seed to soil contact the operation is useless. Ensure you use new seed as old material may not give you the required germination rates.
It is vital to keep tennis playing surfaces clean and free from debris to avoid possible injury to players.
Artifcial courts. Weekly - Keep surface clean with regular sweeping and brushing. Remove any algae and moss from surface. Sand filled systems require regular brushing to maintain manufacturer's recommendations on sand levels and pile heights.
American Fast Dry courts. Before/after games - Keep surface clean, rolling to consolidate surface, levelling and brushing of fast dry materials, brushing to clean lines.
Clay courts. Weekly - Keep surface clean, regular sweeping and brushing to restore playing levels using SISIS Trulute or similar equipment. Topdress any hollows or damaged areas. Repaint lines.
Tarmacadam. Weekly - Keep surfaces clean, regular sweeping and brushing. Repair any hollows or damaged areas. Repaint lines.