Sports Turf Agronomy Advice - May 2025
As we head into May and into early summer (hopefully), spring has once again proved to be a very challenging period for turf managers.
Weather conditions have been far from ideal with growth being the limiting factor in getting recovery from winter wear and disease damage to provide surfaces for play. Good periods of clear blue skies and daylight hours, alongside low night-time temperatures with regular frosts, have put the grass plant under considerable stress. Soil temperatures have remained moderate, but with a rise in temperatures, growth is now starting to increase where moisture is present.
Looking back at the figures from April, GP has further climbed to above 50% which puts it in the good growth category, although this is being hampered in those areas that cannot be irrigated due to the lack of rainfall. The low rainfall numbers in April follow on from those in March and February, which is now reaching the point where it is becoming an issue of concern for many turf managers. Those with winter sports renovations will be requiring irrigation to ensure successful germination and establishment of new swards.
Weekly nitrogen requirements remain low, still below 2kg/week, which highlights how minimal the growth has been up to now. GDD following the 0°C growth degree days model is now over 700, when applying PGR’s it is important to make applications in line with growth and stress, and if growth is being limited by lack of moisture and drought stress, careful consideration should be given to PGR applications .
Click here to review weather data in your region for April. To keep up to date with the weather throughout May visit https://academy.agrovista.co.uk/category/weather
The forecast for early May is for the dry weather we have experienced through the back of April to continue, albeit not the 20°C+ temperatures we have had over the last few days. This will present challenges for those that have zero or limited irrigation, putting pressure on existing systems and staff resources, although the more moderate temperatures will relieve some of the heat stress element.
The increase in night-time temperatures to regularly above 8°C and no planned frosts will mean that areas that have irrigation will experience good growth conditions. The lack of moisture in the ground will have an impact on operations that would typically be carried out this month, such as selective herbicide applications where the plant is under stress and not actively growing, it is best to wait until we have some rainfall and good growth conditions resume to achieve the greatest level of efficacy.
Effective water management
Last month we talked about the crucial role wetting agents can play in achieving optimal playing conditions this spring due to the prolonged dry weather. Given the prolonged dry spell, it seems fitting to cover more on this topic this month, by looking at ways in which you can aim to reduce your water usage through these high demand periods;
- Raise cutting heights to relieve stress on the plant.
- Carry out inspections of the irrigation system, identifying any potential leaks or issues which may cause a bigger issue in future.
- Utilise the use of moisture meters for accurate assessment of moisture levels to avoid over watering.
- In conjunction with taking moisture readings, use hand watering to target specific areas, rather than large scale watering.
- Reduce the frequency of the irrigation cycles, following a pattern of heavy and deep applications and then a dry down period, which will encourage rooting. Shallow and frequent watering can favour undesirable grasses.
- Encouraging the development of more drought tolerant grasses in the sward.
- Utilise products that can help reduce stress on the plant and aid plant functioning when the plant system in under stress and plant biomechanics is reduced.
Pests
May can be the start of activity from the Chafer Grub (May Beetle), an ongoing problem for turf managers. Use Acelepryn where authorised, following the guidance provided by Syngenta. A spring hatch of Leatherjackets appears to be widespread this spring; use of nematodes can be effective in helping to manage this pest. 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.
Tom Wood
B.Sc (Hons) | BASIS | FACTS