Key Tasks for May
The emphasis at this time of the year will be on mowing frequency, as long as there is sufficient moisture within the soil
Mowing. Greens should be mown at least three times a week, with some grooming, verti-cutting or brushing being undertaken on a weekly or twice weekly cycle to improve air movement and reduce thatch levels building up in the sward profile.
The sward will be actively growing due to the increased soil temperatures, coupled with the stimulation of fertiliser applications. Regular mowing will be required to maintain sward height at around 4-5mm. Verti-cutting/grooming fortnightly can be carried out to help speed up the green and help improve the health of your turf.
Aeration should continue, using a mix of micro, needle or star tines which give maximum effect and almost zero turf disturbance.
Regular use of a sarrel roller will be beneficial and the use of micro tines to aerate the green will help reduce soil compaction, 'vent' the root-zone and to allow water to move quickly from the surface and into the root-zone, thus encouraging the turf to root deeper.
Irrigation: Soil and air temperatures usually increase in May, often bringing on the need to irrigate. If soil profiles, particularly sandy soils, are allowed to dry out too much they often become water repellent (hydrophobic), a state when soils can become difficult to re-wet. Often the first areas to suffer on greens particularly crown greens are the high spots on the green. You may need to spend more time hand watering these problem areas.
When you do water, ensure you go to a depth of 100-150mm to encourage the roots to go down to find the water.
One of the benefits of doing this monthly agronomy diary is that you get to build up an excellent picture of what the conditions have been like over a period of time.
As we head into May, I can’t clearly recall what conditions were like at this time last year, but reading back through my notes, it is apparent it was very similar to what we have experienced this year. Very challenging in terms of producing growth that will either bring together a surface or give sufficient recovery from play. Relatively mild day temperatures, with periods of sunshine coupled with low night-time temperatures, have put the grass plant under considerable stress; especially when you also factor in the lack of rainfall we have had. Irrigation can and has had to be used, but in doing so, you are acutely aware that the irrigation water is cold after a long winter and isn’t helping to encourage soil temperatures to rise. This has pushed progress a bit further back for some in terms of where they predicted their surfaces would be heading into May. It is not ideal to unrealistically manufacture growth in these conditions, therefore it is advised to work with nature, where possible, rather than try to force growth.
The forecasted month ahead for May looks more encouraging, as night- time temperatures appear more favourable, with good day-time temperatures in the mid-teens. 26 days of the month are forecast at 15°C or above during the day and 26 days with night-time temperatures of 7°C or above, which will help to start generating some consistent growth, putting more control back in the hands of the turf manager. There appears to be a spell of rainfall early in the month, which I imagine will be welcomed by most, and then as the month progresses the forecast looks set to keep improving with a period of dry weather. This combination of moisture and temperature increase should stimulate growth and assist in giving surfaces adequate levels of recovery or grow-in from renovation work; allowing for refinements of surfaces and consistency in performance.
Plant nutrition will now be well under way for many, whether granular or liquid, and depending on the site etc… applications will be different across the country. Given the recent weather challenges from the extremely low temperatures, many may well be waiting to see a response from the latest applications, depending on when it was timed. The recent stress that the plant has been under is not to be underestimated, whether it be from the extremely low amounts of rainfall we have had, or the stress from cold irrigation water, or the dramatic change from day to night temperatures. It is important to try and mitigate or alleviate these stresses. There are already signs of Poa annua seedheads appearing, due to these underlying stresses on the plant. Grooming can be utilised to physically remove seedheads, although this should be weighed up against the action of creating a new seedbed for any seeds which don’t make it into the grass box. Another important factor is current growth conditions and how well the plant will be able to recover from such actions.
Nutritional inputs may need to be adjusted to meet the demands of the weather. Dry conditions may affect the performance of granular fertilisers, where there is less nutrient available in solution due to dry conditions. Therefore, until rainfall is expected, utilising liquid applications of a readily available nitrogen source, such as ammonium sulphate, will encourage gradual growth and recovery.
Using surfactants where possible will assist in even moisture distribution through the soil which, in turn, improves plant health via improved rooting and nutrient uptake. Whilst applications of wetting agents are being made, it is a good opportunity to include biostimulants in the tank, which can be targeted to reach the rootzone area of the profile. These biostimulants will help mitigate any plant stress that is present.
Recently, there have been the first sightings of Crane fly emergence, and brings to the fore one of the major issues currently for turf managers. There is still no registered chemical control for this pest to be applied at this time of year, however if damage is significant, there is the option to consider a spring application of nematodes to try combat the problem. Steinernema feltiae can be used at soil temperatures above 8°C and Steinernema carpocapsae above 13°C, therefore it’s important to choose the right treatment for your site at this time of year. We will wait to see if emergency approval is granted for the use of Acelepryn on chafer grubs in 2022. Installing pheromone traps allows you to monitor which species you have on your site and to plan accordingly; it also means you can track the peak flight period to time your product application for best results.
The forecast looks good for May, so let’s hope it brings consistent growth which will allow the best surfaces to be produced.
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- 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.