Key Tasks for June
With things getting back to normal (almost), ongoing maintenance of the greens will now be required. With the long daylight hours and warm temperatures expected in June, 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.
Fortunately, the further easing of restrictions on May 17th has meant there are much more activities taking place and more for everyone to do, which is great. Hopefully, later this month the next step of easing of restrictions will come into place too. I think those that were doing a rain dance in April, might have wished they had danced a little less come early May, where people up and down the country were experiencing more rainfall in one day than the whole of April combined. Changes in weather patterns are clear to see and it’s another factor we must try and deal with the best we can. Having said that, it makes planning grounds management incredibly difficult and sometimes the pressure the wrong weather, at the wrong time, brings is very challenging. Certainly, the weather conditions from the end of 2020 right through to the end of May have been very difficult to work with.
Temperatures finally look set to increase in June, with 27 out of 30 days at 16° or above. More importantly the low temperatures are increasing, with again 27 out 30 days forecast to be 9° or above. This was a big issue last month with night- time low temperatures holding back any real gains in terms of strong growth and recovery. The change this month should pave the way for more consistency in growth.
So, it is later this year than many would have liked, but we are starting to see late spring give way to early summer and, as we transition through this period, we can focus on how best to provide the plant with what it needs to remain healthy and to provide excellent playing surfaces. Some key areas of focus are covered below:
More consistent soil temperatures provide the ideal environment for fertilisers which rely on microbial activity to release the nitrogen. Examples of these are organic, organo- mineral, methylene urea (MU) and crotonylidene diurea (CDU). These forms release nitrogen gradually over a period of time and can be classed as slow release. This release pattern complements the amount of growth at this time of year, as the release is dependent on environmental and microbial activity. This reduces any flushes which would produce lush soft top growth. Utilising this technology as a source of underlying nutrition can then be complemented, when required, by the plant, with additional inputs to further support growth and plant health. This gives the turf manager greater flexibility. These inputs could be in the form of liquid nutrition, plant response elicitors, plant growth regulators, liquid iron or biostimulants. Utilising biostimulants, such as seaweeds, amino acids, carbohydrates and fulvic (and humic) acids, can also help to mitigate many of the biotic and abiotic stresses. Cold pressed liquid seaweed is full of plant hormones, which are useful for helping mitigate against water and heat stress. Amino acids and carbohydrates (sugars) are great stress relievers, given that they are a readily available source of a key resource the plant requires and must expend energy to produce itself, therefore stress can be reduced following applications. Fulvic acids condition the soil environment which support the natural soil processes of nutrient cycling and biological processing, increasing nutrient uptake and overall plant and soil health.
The use of wetting agents can be key to providing consistency in moisture management throughout a rootzone. The aim being to have even moisture distribution through the rootzone, within a determined ±% tolerance set by the turf manager, which helps eliminate any excessively dry or wet spots. This not only helps promote good rooting but also assists efficient nutrient uptake, maximising any inputs that have been applied. Early applications of block co-polymers will now have accumulated in the soil and will help maintain surface quality through any dry periods should they appear. If early applications couldn’t be made, then a penetrant wetting agent will break surface tension and allow for infiltration, although water holding will be reduced. Cultural methods go hand in hand with such a programme and sarrel rolling keeps surfaces open allowing water to infiltrate and is also important for gaseous exchange. This can be followed up with regular pencil tine aeration to create deeper channels for water movement and root development.
Plant growth regulators (trinexapac-ethyl and prohexadione-calcium), applied throughout the growing season, can mitigate stresses through dry periods. Deeper rooting is promoted which allows the grass plant to cope better with stresses and ET rates have also been seen to be reduced, meaning the plant is put under less water stress and can conserve more energy.
When irrigating, it is more advantageous to drench the profile and follow this with a dry down period, which will encourage roots to penetrate down the profile and search for water reserves. In comparison, regular little and often approach only serves to keep the upper profile moist which can lead to soft surfaces, promote annual meadow grass dominance and encourage disease.
Anthracnose is now a major disease of concern as we move into summer, especially on the back of the spring stress the plant has been under. The disease is triggered by stress factors such as low fertility, compaction, drought etc…Therefore, adequate fertility and soil moisture levels are ways to lessen the impact of these fungal pathogens by mitigating where possible any plant stress. The key with this disease is to be aware of your historic outbreaks, and time any maintenance or inputs in advance to reduce the likelihood of a further outbreak this year. If required, a preventative fungicide can be applied ahead of a high-pressure period.
Acelepryn has been awarded an emergency authorisation for chafer grub control again in 2021, covering golf courses (restricted areas), airfields, horse racecourses and gallops. As with previous years, applications of Acelepryn are governed by a stewardship process and all releases of stock must be validated by a BASIS qualified advisor.
Any pheromone traps deployed in May should have shown up any activity of garden chafers on sites where that species is present. It is important to regularly monitor and record activity so that informed decisions can be made about the best way to manage the issue.
Treatments, such as the relevant entomopathogenic nematodes, can be made on sites where emergency approval is not granted. Apply 4-5 weeks after the peak adult flying time has been recorded, ensuring that: the number of larvae in the soil has reached the action threshold; the soil temperature is within the tolerance limits for the nematode; the soil is moist and has been aerated; further rain is forecast or you can apply irrigation. Continue to keep the area well-watered for at least two weeks.
There have been significant reportings of issues with leatherjacket damage this spring, which has no doubt been exacerbated by the poor growth that has been experienced, leading to stressed and weakened turf. There is no emergency authorisation for the control of this pest currently. Use of entomopathogenic nematodes early in the season need to be done with care, ensuring the correct species are used and realistic expectations are set in terms of achievable results.
- 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.