Key Tasks for August
Mowing daily, or at least three times a week, to maintain sward height at around 4-8mm. Some clubs reduce their mowing heights further, perhaps down to 3mm to help speed up the greens for club competitions. Prolonged mowing at these heights will lead to plant stress.
The speed of greens can be affected by other factors - too much thatch is the main cause of slow greens, or the fact that the greens have not had enough topdressings to maintain levels.
Many bowlers complain about slow, inconsistent greens, often resulting in clubs trying to speed them up by shaving off more grass. In the short term, this may increase speed but, in the long term, it will be very damaging to the green.
- Remove and control the rate of unwanted vegetative growth (thatch and side growth) by regular grooming and verticutting operations.
- Light applications of topdressing will restore and maintain surface levels, thus increasing green speed.
- Mowing in several directions to reduce nap layering will help increase green speed.
- Double cutting for matches will increase green speed.
- Controlling soil moisture will help influence green speed.
- Brushing/switching of the playing surface keeps the green clean and removes any dew or surface water. Keeping the surface dry will improve resistance to disease.
Mowing. Too many bowls clubs choose to cut their greens far too low during the summer months, mainly influenced by club members who want faster greens. Do not be tempted to cut below 4mm unless you have the expertise, resources and knowledge to support this type of maintenance regime. Mowing the green below 4mm will, in the short term, give the members what they want - fast greens - however, there is often a cost to bear for doing this. It generally comes in the form of the green suffering in many ways, grass cover begins to thin out, bare areas develop which allow weeds and mosses to establish. Beneath the surface, the constant rolling will have compacted the soil profile, reducing the air spaces. This leads to poorer root growth, less movement of water and resulting in flooded surfaces.
In fact, the most common cause of slow bowling greens is the presence of a layer of accumulated organic fibre, commonly known as thatch. This is found just below the surface and is caused by the accumulation of matted grass stems. This is easily detectable when you walk across the green and the surface feels soft.
Aeration is a key activity to ensure that there is a good air/gas exchange going on in the soil profile. The use of a sarel roller (depth 5mm) helps to keep the surface open without disturbing the playing surface. Deeper aeration should only be done with micro tines when moist conditions allow penetration.
Irrigation. Water is influential in all chemical, physiological and biological processes of plant growth. The soil/plant water relationships is critical to the sustainability of any grass plant. Having an understanding of these relationships is critical. All grass plants are a continuum of water movement. Over 90% of the plant's water requirements are transported through the plant from the soil profile, via the roots and stem tissues into the leaves and out into the atmosphere. Knowledge of these relationships is important when designing and operating irrigation systems. The main aim is to achieve a water balance within the soil profile ensuring that the grass plant is able to access available water from the soil.
Irrigation scheduling by the water balance approach is based on estimating the soil water content. In the field, daily evapotranspiration (ET) amounts are withdrawn from storage in the soil profile. Any rainfall or irrigation are added to storage. Should the water balance calculations project soil water to drop below some minimum level, irrigation is indicated. Weather forecasts enable prediction of ET rates and projection of soil water balance to indicate whether irrigation is needed in the near future.Soil water relationships are key drivers in maintaining plant health, so it is vitally important you readily water your bowling green and ensure the plant does not become stressed from the lack of water, on the other hand you do not want to be over watering, as this may bring you other problems.
Generally, you should be looking at a programme of scarifying in several directions to remove unwanted thatch layers and dead matter, aerating with some deep solid tines to break up compaction, topdressing with some 70-30 topdressing to restore levels, and overseeding with some new grass seed.
Unfortunately, one of the deciding factors that often reduces the effectiveness of these planned works is the amount of money the club has available, especially given the current circumstances. 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).
It's hard to believe that July is drawing to a close and we will soon be into August, with shorter days and cooler nights.
July has given us some very high temperatures, and for prolonged periods, which has brought with it challenges for turf managers, especially those without or with unreliable irrigation systems. When the rain has come, it has been well received. These extreme weather conditions put extra stress onto the plant at a time when stress is already exacerbated from the intensive management carried out to provide excellent playing surfaces. This in turn can be the tipping point for pathogen populations to increase and disease incidence to occur. Therefore, attention should be on stress management and alleviation where possible.
The forecast for August looks far more consistent with daily high temperatures typically being around 20°C. The rainfall looks scattered which means those that are desperate for some rain will get some respite and a good chance at some recovery. The key here is to ensure that those areas that need water the most will be receptive to it when it comes. Water will run off areas that have become hydrophobic; utilising a surfactant to break the surface tension and allow the water to penetrate into the profile can have a positive impact on recovery of drought stressed areas.
The increase in weather extremes is ultimately influencing how successful our nutritional plans are. Little and often nutrition provides a steady supply of the nutrients required, minimising peaks and troughs in growth and assisting in providing excellent surfaces. However, changes in the weather which brings heavy downpours impacts on the effectiveness of this method. It essential that plans are proactive and reactive to the day to day conditions and not simply what was drafted out at the start of the season. Granular fertiliser with a portion of high-quality slow release technology offers a base nutrition which can be topped by liquids as required. Calcium and Potassium are both key nutrients when considering biotic and abiotic stress, due to their role in cell walls and water regulation. Therefore, looking out for these when selecting your fertiliser is recommended.
This can be a key time of year for renovations, with weather conditions ideal for getting recovery and establishment of seed. Practices will vary across the different surfaces, however having objectives planned out will increase the probability of having a successful renovation. If over-seeding, consideration should be given to selecting the right cultivars for the intended usage. Organic matter removal can be a major component of renovation work, and ensuring that the maximum amount is removed with minimal disruption is recommended. Carefully selecting the most suitable method of removal to ensure the desired outcome is achieved efficiently is important.
Planning work out in advance, at this time in the season, allows for a full recovery of the plant and establishment of new seed in time for autumn and winter. Utilising biostimulants, such as liquid seaweed and humic acids, will further promote seed germination and establishment in combination with the usual renovation fertilisers.
Later in the month, the cooler nights will increase the probability of dew occurrence. The increase in leaf wetness will undoubtedly increase disease pressure. At a time when growth potential is still high and cutting is still regular, utilising dew dispersant technology to reduce leaf wetness is only going to be effective for short periods of time, due to the growth rate of the plant. This isn't to say that this is not an effective management tool for reducing leaf wetness, as long as expectations on product performance in these conditions is taken into consideration. The amount of time that they do last can just be enough to see you through a high-pressure period, and thus can be invaluable.
The purchase window for chafer grubs control expires on 4th August and the storage and application window ends on the 31th August 2021. A separate authorisation is awaiting approval for Leatherjackets, but this is yet to be approved. As with previous years, all applications must be approved by a BASIS qualified advisor.
For anyone not able to apply Acelepryn, cultural and biological controls in the form of Entomopathogenic nematodes are the only legally authorised controls available. As with the specific restrictions of application for Acelepryn, these are in line with best practice Integrated Pest Management. This biological control method requires warmth and moisture in the soil to be most effective, and as such this time of year provides an ideal window. Targeting larvae when they are small and susceptible gives the nematodes the best chance of success.
- 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.