Key Tasks for June
With some managed and controlled play allowed, ongoing maintenance of the greens will now be required. With the long daylight hours and warm temperatures we are experiencing, grass growth will be quite prolific. Continue to carry out routine maintenance tasks, mowing, verticutting, fertilising, watering to keep the green in a playable condition. Grass growth will dictate mowing frequencies, in most cases clubs are cutting daily or on a three to four times a week regime. Only apply fertilisers if you have significant moisture in the green; clubs that are struggling to water should refrain from applying feeds whilst the greens are dry. Try and keep a diary of what work you have undertaken on your green, and keep records of how it has performed; take some pictures of the green and make note of any issues/problems you have.
Get into the habit of taking a number of soil core samples to monitor what's happening underground; a visual look at a soil profile will enable you to monitor thatch content, moisture levels and root depth.
Mowing. With regard to mowing, ensure your mower is kept sharp and set at the correct height. No two greens are the same; Height of cut (HOC) will vary from green to green, with HOC influenced by several factors, type of mower used, condition of the green, sward composition and surface levels. In general, HOC will range between 3mm-8mm during the growing season, with most clubs cutting at around 5mm.
Some clubs will reduce their mowing heights, perhaps down to 3mm, to help speed up the greens for club competitions. Prolonged mowing at these heights will lead to plant stress. As an alternative, instead of reducing the height, do a double cut (in different directions), this will speed up the greens without reducing the grass height. 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.
Irrigation. Nowadays, irrigation is an important and integral part of the turf grass management industry, especially as the demand for better quality playing surfaces has increased. Therefore, careful consideration and investment in a decent watering system is a key requirement to managing fine turf surfaces. Irrigation is essential for a number of reasons:
- for plant survival and growth
- for soil formation
- for soil strength
- for chemical transport
- for managing playability
- for presentation
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.
It is also important to state that overwatering can equally be damaging to your surface. Keeping the surface waterlogged will reduce air porosity and decline plant growth; constant shallow watering will also increase Poa annua populations. Ideally, you should apply a sufficient amount of water to flood up the green and then allow to drain for two - three days. This allows the water to get deeper into the soil profile.
This is often a contentious point between groundsmen and players.
Many players and committees insist on keeping the ends in the same position and direction, usually for obscure reasons such as "it's my lucky rink".
Playing in the same direction with the rink ends in the same position will cause uneven wear on what should be a flat, level green. Ruts and depressions will occur, causing the bowl not to roll true.
The rink settings should be moved laterally and directionally every 3 days or so, playing across and up and down the green.
On the same basis, all rinks should be used in rotation so that wear is evenly spread across the green. Just using the centre links will quickly affect the level of the green.
As parts of the country begin to open back up for sporting activity, there is no let-up in recent pressures for many across the industry. With effects of the Covid-19 crisis ongoing, there will be a lot of variance in what is achievable for individual facilities but, as late spring gives way to early summer, let’s look at how we can focus on providing the grass plant with some helpful assistance where circumstances allow.
Consistently warm soil temperatures in June create ideal conditions for fertilisers with an organic component, whether that be straight organic fertilisers or organo-mineral. Organic sources of nutrition help to support the soil food web and manage the soil-plant system in an holistic fashion. Spring inputs of nitrogen aiming to get things going can be reduced and grass growth will naturally start to drop back as temperatures rise. In the wild, the plant would have now gone through its leafy growth spurt and be diverting energy into setting flower.
Calcium is a key driver of growth for roots and shoots, as it is responsible for the construction of cell walls. Calcium availability can become limited in dry soils, so ensuring soil levels are adequate and supplementing with foliar calcium helps to maintain good health. Calcium, along with potassium, are essential for regulating stomatal function, helping the plant to better react to the onset of heat and water stress. Cold pressed liquid seaweeds contain plant hormones which also help to regulate against water stress and are a significant resource to be employed. Seaweed also contains hormones which promote germination and establishment.
The use of wetting agents, where it was feasible this spring, will start to pay dividends during June if hot weather occurs. Ideally, these should have started with the application of a block co-polymer in March at the latest, to give the soil a chance for the chemistry to accumulate in the soil. Where that wasn’t able to take place, or where planned applications were interrupted, penetrants surfactants will facilitate increase of water from the surface, although the holding capacity in the soil will be reduced.
Regular sarrel tine aeration is a key cultural means of maintaining soil moisture levels as the shallow but tightly spaced tines puncture a large percentage of the surface area, allowing gas to escape from the soil and better aiding the percolation of water from the surface.
Growth regulators such a trinexapac-ethyl and prohexadione-calcium applied during periods of good growth in anticipation of hot dry weather to come will help the plant to conserve energy and manage water stress, again mitigating drought pressure.
With respect to irrigation, applying water at the end of a hot day creates a nice thermal blanket, trapping a greater percentage of the day’s heat in the soil.
Little and often watering is appropriate for germinating seed and very young plants, but it is advantageous to thoroughly wet the profile and then let the soil dry down to just above wilting point if you can. This encourages the roots to penetrate and allows carbon dioxide to leave the soil and life-giving oxygen to enter.
Little and often watering also maintains surface humidity and will encourage algae, mould and fungi such a botrytis and Rhizoctonia spp. to attack swards.
Disease such as dollar spot and anthracnose may become a concern as the month progresses. Ensuring adequate fertility and soil moisture levels are cultural means to lessen the impact of these fungal pathogens by mitigating plant stress. Closely monitor weather forecasts, your historical site records and disease predictors to keep an eye out for major outbreaks. Resorting to a systemic fungicide if required.
Chafer grub traps deployed in May should have shown up garden chafers on sites where that species is present. Regular monitoring and recoding of other areas for adult beetles of the other species will facilitate the prediction of accurate intervention points for treatments such as entomopathogenic nematodes and Acelepryn later in the summer, should you be managing a site authorised for application of this insecticide. Acelepryn has been awarded an emergency authorisation again in 2020 but this time it is split into two windows, one each for Chafer grubs and leatherjackets respectively. As with 2018 and 2019 applications of Acelepryn are governed by a stewardship process and all releases of stock must be validated by a BASIS qualified advisor.
Senior Technical Manager – Amenity | MBPR
- 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.