Key Tasks for September
Now that we are back to some form of normality, do not be afraid to take a couple of core samples from your green, enabling you to see what lies below the surface. On examination, you should be able to see how much thatch you have and the condition of the soil.
Grass growth will start to slow down once soil and air temperatures drop below double figures. Your main concern for September will be organising your end of season renovation work; the extent and nature of the work will be entirely down to the condition of the green and what work you can afford to carry out.
Unfortunately, one of the deciding factors that often reduces the effectiveness of these planned works is the amount of money budget the club has available. It can cost anything between £1200-£1500 for a contractor to come in and do all the work.
Savings can be made if the club undertake the work themselves; however, the effectiveness of the work carried out will be determined by the equipment they have at their disposal. Savings can also be made if clubs buy materials in bulk (several clubs group buying).
The best way to balance the health of the grass plant and to achieve good green speed is to promote and carry out effective cultural practices to maintain surface playability.
The following activities are generally implemented during autumn renovations and usually carried out in the following order, when conditions allow. The sequence of operations and their intensity will vary from green to green according to the condition at the end of the season.
Mowing the sward, preparing surfaces for renovation: lower cutting height to about 3-4mm to clean and prepare green for renovation operations. The mower can then be used to clean up the green after scarifying has been completed. With the season finished and the green closed down for the winter, mowing will only be required to maintain a winter height of cut at 8-12mm. Some clubs are now using rotary mowers to keep the greens tidy through the winter months. This methods does two jobs in one, it keeps the grass topped and hoovers up any surface debris, such as twigs and leaves.
Scarification, removal of unwanted debris: collect and disposal of arisings. Depending on the severity of the thatch, you may need to scarify several times in different directions. However, in most cases, if regular verticutting/grooming has taken place during the growing season, you would probably only be required to scarify in two directions. Do not scarify at right angles to the previous scarification line. Depth of scarification between 4-15mm, depending on depth of thatch to remove.
Aeration is the decompaction of soil, improving air and gas exchange in the soil profile. Depending on the turf's condition, you can choose to carry out hollow or solid tine spiking. Hollow tines are generally used on a bi-annual basis or when you have a severe thatch problem. Depth of aeration will be determined by the depth of your soil profile and what problems you want to rectify. Hollow tining is best achieved to a depth of between 75-100mm. Solid or slit tines can be set to penetrate deeper, ideally between 150-200mm.
Topdressing restores levels and improves surface drainage. Ensure you use compatible topdressing materials, sands, sand/soil mixes. Spreading can be achieved by several methods, utilising pedestrian or ride-on, disc or drop action top spreaders, or by hand using a shovel and a barrow. Best carried out in dry weather. It is important that the topdressings are spread uniformly. Brush to incorporate dressings and to help the grass stand back up. Brush in with a lute or drag brush/mat to restore levels.
Overseeding restores grass populations. It is important to ensure a good groove or hole is made to receive the seed; good seed to soil contact is essential for seed germination. Good moisture and soil temperatures will see the seed germinate between 7-14 days.
Fertilising, provides nutrients for grass growth. Apply a low N nitrogen fertiliser product, something like an NPK 5:5:15 to help the sward through the autumn period.
Irrigation is essential after renovations to ensure your seed germinates.
Another month has flown by and September is now upon us. This month traditionally sees a shift in weather conditions, which become more autumnal, with less extreme heat and cooler temperatures, and more frequent rainfall. Mornings and night become noticeably darker and, importantly for turf managers, dew on the grass plant becomes a more regular occurrence.
August’s weather has provided good conditions for those who have carried out any maintenance, with positive conditions to promote recovery. There has been a mixture of good temperatures with sunshine and showers which has maintained soil temperatures and provided plenty of moisture for germination after seeding.
September looks set to continue from August, with conditions still favourable for any renovation work planned. Therefore, those who couldn’t get this work done in August will still have a good opportunity for success this month. These conditions will also continue to provide strong growth and recovery from areas with high play. If overseeding work is being carried out, ensuring good contact with the soil will allow the seed to utilise the moisture in the ground. Plant growth regulators such as Prohexadione-calcium and trinexapac-ethyl can be used at this time to help in the development of new seed by holding back the competition from existing mature plants in the sward, creating a more favourable environment for establishment.
As moisture levels increase in the soil and on the leaf, this favours disease development, as the 3 parts of the disease triangle start to come together. For many this will play a major part in planning over the coming months, alongside carefully selecting the right nutrition. As we enter this period when conditions become far more conducive for disease development, with heavy dews, less sunlight, more shade etc…. management of these stress factors becomes essential. Moisture and water management are key in restricting disease development and utilising applications of dew suppressants, even if short-lived, can be just enough to tip the balance in your favour in the right conditions. Similarly, penetrant wetting agents can assist in allowing water to easily move through the profile. However, consideration should be given to the make-up of the soil profile and how effective these can be in certain situations. Once any renovation work is complete, ensuring the cutting units are sharpened and providing a clean cut will also help reduce any potential weak entry points that a pathogen looking for a host is likely to exploit.
Providing adequate nutrition to promote recovery from any maintenance work, or to keep growth consistent and strong to support producing quality surfaces, are factors to consider.
Once any new seed has run out of its own supply of nutrients, ensuring there is adequate supply will assist it getting better recovery. Including a suitable amount of phosphorous helps supply energy to synthesise ATP. A healthy amount of Calcium will not only strengthen the primary cell walls, fortifying defences against pathogenic fungal attack, but also encourage cellular generation at the growing tips of roots and within new leaves.
Applications of high levels of nitrogen can further encourage disease outbreak. Research shows that selecting a balanced autumn fertiliser can consequently result in better spring performance. As such, over applying at this point in the season is likely to lead to excessive soft leaf growth, which is more susceptible to disease attack. Choosing an appropriate nitrogen source that will provide a staged release of nutrients, as the conditions are suitable, will maintain turf health and strengthen against disease attack.
The Emergency Authorisation for Acelepryn for control of Leatherjackets has now been confirmed and this can be purchased now, once the stewardship form has been completed. This applies to golf courses, airfields and racecourses only. The latest time for application is 29th November. Remember - Acelepryn is most active on the 1st and 2nd instar stages and therefore timing is critical to maximise success.
Application of the product for control of adult Chafers has now passed and should have been completed by 31st August. Where chemical control is not authorised, entomopahogenic nematodes can be applied, with warm soil temperatures and available moisture being ideal conditions to get the best out of an application. The entomopahogenic nematodes swim in the water film on soil particles in their bid to search out a larval host.
The adult crane fly typically emerges in late July to September. The adult flies commence egg laying almost immediately, with hatching and larvae emergence about two weeks later. You can check reported sightings of crane fly species on the Pest Tracker on the GreenCast website. To aid effective timing of treatment, ensure the product is in the soil at the optimum time for egg hatch and initial larvae activity.
With the increased moisture content in August, worm activity has started and is already causing issues for turf managers. There are still no legal controls for earthworms and any product which is applied to directly affect them is done so illegally. Cultural management continues to be the only route currently available, which can include a combination of practices such as localised surface acidification, removal of grass clippings to reduce their food source and sanding of surfaces to assist in the drying out and dispersal of casts, leading to less negative lasting impression on the surface from the cast.
- Keep machines overhauled and clean.
- Inspect and repair any watering or irrigation systems.
- Continue to check and service your floodlighting systems.
- Replace any worn tines on your aeration equipment.