Key Tasks for July
How good is it to be getting back to some sort of normality? Greens are back in use and players can make the most for what is forecast to be a good July weather-wise. So, it's all hands to the pump for the grounds team.
With the long daylight hours and warm temperatures, grass growth will be quite prolific if there is plenty of moisture about.
- 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.
Aeration is a key activity to ensure that there is a good air/gas exchange going on in the soil profile. Providing the green is adequately irrigated, the use of a sarrel roller (depth 5mm) helps keep the surface open without disturbing the playing surface. Deeper aeration should only be done with micro tines when conditions allow, as we do not want to risk disturbing the surface, especially during the playing season.
Topdressing is usually carried out in spring and autumn in conjunction with the renovation programmes. However, some bowling clubs have a policy of applying topdressing materials during the season. It is important that an appropriate material is sourced to ensure compatibility with the existing rootzone materials of your green. The last thing you want to encourage are rootbreaks in the green.
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 we approach halfway through the year, this brings about a familiar feeling of, “Where has the time gone?” and “Is it nearly July already?” It was unfortunate that we had the news that further easing of restrictions was to be delayed, but hopefully that will happen this month. Fortunately, many sports are in full swing, to name a few we have seen Test cricket, the Euros and Wimbledon start.
June finally brought us some consistent temperatures, which actually continued on from the last week in May. This provided more suitable growing conditions compared to previous fluctuating weather which was challenging to manage. This was long overdue and has meant that everything has seemed a little bit later this season in comparison to other years. Although the average rainfall for June is currently at 40mm, which is nearly half of what fell up to the same point last month (average 75.2mm), it wasn’t until the 25th June that the average monthly rainfall went above 10mm, which gives an indication of how little water has fallen since the back end of May. This has proven challenging for those without or with limited and restricted irrigation systems. As such, the recent rainfall has been much needed by many across the different regions.
July temperatures look set to continue to be decent, with most days around 19°C or above. Rainfall is forecast to be sporadic which should help prevent surfaces drying down too much. With warmer temperatures comes the possibility of an increase in humidity. When temperature is higher, the air can hold more water vapour, meaning that when climate conditions are warmer the humidity level can be higher. As an example, at 28°C a densely saturated amount of air may contain 28 grams of water per cubic metre, but only 8 grams of water per cubic metre of air at just 8°C. Higher humidity can increase the likelihood of the development and growth of fungal pathogens.
Water management is a key tool for maximising overall plant health, ensuring there is enough to support nutrient uptake and growth whilst ensuring there isn’t too much that will restrict root growth, prevent gaseous exchange and reduce available oxygen. Following a water management programme is one way to help ensure water is distributed evenly across the whole area and reduce any localised dry patches. When using products to achieve this, the earlier in the season they are applied can have an impact on the results they achieve. Therefore, ensuring applications are made well in advance of drought conditions is recommended. Having less water around the soil surface and base of the plant helps reduce humidity in this area, which helps to mitigate the ability of fungal diseases to proliferate. This restricts the conditions that are suitable for disease development. Regular aeration, using a variety of tine depths help maintain pathways for water to enter the rootzone and pass through it.
The forecasted conditions for the month will provide strong growth. As such, the application of a plant growth regulator alongside any nutrition is a useful management tool with a range of benefits. Reduced clipping yield is a notable advantage, plus many others including increased rooting, regulated growth of different grass species, improving surface conditions, better turf colour through an increase in chlorophyll content and lower ET rates. Where growth is strong, nutrition may only need to be applied to provide enough recovery from wear. All forms, liquid, granular and soluble are suitable and each site will have their own preference. Liquid applications allow greater control in applications supplying little and often, and further beneficial stress relieving biostimulants such as amino acids and sugars can easily be added to the spray solution.
For Anthracnose (Colletotrichum cereale), warm, humid weather and increased light intensity are the primary environmental factors controlling the development of conidia. Laboratory studies indicate that Colletotrichum cereale produces conidia at temperatures between 24‑32°C with increased maturity of conidia observed at 28°C compared with lower temperatures. Once conidia have been excreted from the acervuli in a water‑soluble matrix, they can be spread by wind, water or human activity, but need continued leaf surface moisture to establish. Little and often applications of nitrogen have been shown to mitigate the development of the disease, as has minimising any stresses on the plant. Applied preventatively fungicides are available as a method of control, although some will find the above measures sufficient when dealing with this disease.
Emergency authorisation for Acelepryn has been issued for the treatment of chafer grubs only. The purchase window for chafer grubs expires on 4th August and the storage and application window ends on the 31st 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.
- 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.