Sports Turf Agronomy Advice - April 2025
This month brings the ‘real feel’ of spring, with the clocks changing, longer days, more light and increasing temperatures, which have now started to provide some essential turf growth and recovery.
Up to now, the cool night-time temperatures have held back any real gains in growth, but in comparison to last year, the start to the year has been excellent. Dry weather has allowed many maintenance operations to be carried out and real progress being made on sites up and down the country; a stark difference to last spring, when cutting wasn’t even viable until well into Apil due to unsuitable ground conditions. May it long continue, although I have already started to see in some locations the need for a drop of water as the ground is unusually dry for the time of year and even aeration holes are starting to widen.
Looking back at the figures from March, GP has started to rise to around 50%, which means we are approaching what would be classed as good growth conditions. Which is why those who have carried out some maintenance work have seen good recovery. It hasn’t been explosive growth, but it has been consistent and enough for what has been required. Rainfall has been minimal all month with very few days of rainfall, which follows on from a relatively dry February too. Although the day temperatures have reached good numbers, it is the low night temperatures which have stopped any surges in growth. This is highlighted by the small amount of weekly Nitrogen requirements.
GDD following the 0°C growth degree days model is now over 400 which, if you haven’t already, means that you can start looking at applying the first prohexadione-calcium plant growth regulator application of the season.
Click here to review weather data in your region for March. To keep up to date with the weather throughout April visit https://academy.agrovista.co.uk/category/weather
The forecast for early April look likely to be a continuation of the weather we have experienced at the back end of March. Temperatures are predicted to get up into the mid-teens and there is
minimal rainfall forecast, although night temperatures are holding relatively cool, which will have an impact on the amount of growth we can expect. It is only towards the back end of the month that things start to look a little more unsettled, however it is here that the prediction is for the night temperatures to rise to late single figures/10+, which will be good for spring growth.
Wetting agent technologies
Wetting agents could play a crucial role in achieving optimal playing conditions this spring due to the prolonged dry weather. They should be used in accordance with the desired outcome as not all wetting agent products utilise the same technologies.
Block co-polymers are now commonly used and are safe on fine and sports turf areas. They help to reduce water repellence issues in rootzones and soils, improve soil water content and the amount of plant available water. Within the category of block co-polymer, you have straight block co-polymer to enhance water movement into the rootzone and reverse block co-polymer (retainer) which enhances moisture retention in the rootzone. Blends of both, straight and reverse block co-polymer, are now commonplace within the industry, which aim to utilise the benefits of both technologies.
Other products available include those containing Alkyl Polyglucosides which make use of a sugar molecule reacted with a fatty acid to reduce water repellence. These can be mixed with straight block co-polymers and are widely used in the turfgrass industry. Lastly, there is the unique modified methyl capped block co-polymer which creates a thin film of water around the soil particle which reduces the ability of the soil to completely dry out, meaning low volumetric water content can be achieved without becoming hydrophobic. Determining what the goal is for your site in relation to water management and distribution is key to deciding which technologies are going to help you achieve it.
Plant growth regulation
Poa annua seed head development can start early, especially in our current climates of highly unpredictable weather patterns, which bring with them stress to the plant. Stress on poa annua from dry conditions, such as now, will engage the survival strategy of the plant and lead to the generation of new seed. This is a massive consumer of the plant’s carbohydrate resources.
Applying a plant growth regulator that is formulated to work at cooler conditions, such as prohexadione calcium, to interfere and suppress the development of the reproductive seed, can help re-direct the ‘saved’ carbohydrates away from seed head production into other plant development processes, improving overall plant health at a time of plant stress, such as tillering and root development.
Rooting
As well as plant growth regulators being used to encourage rooting, April is an opportune time to focus applications around stimulating as much rooting as possible as this is when root growth is at its peak. High nitrogen applications at this point would only serve to stimulate excess leaf growth at the expense of root development. Therefore, it is key to align the nitrogen inputs with the requirements of the plant. There’s a plethora of products available on the market that report to have beneficial effects in root development such as seaweed.
Products high in auxin content will have a positive effect on root development, as it is auxin that is a key regulator of lateral root formation, which is essential for building a robust rootmass in the rootzone; at the same time, ensuring there is some phosphorous supplied within any fertiliser applications will also encourage the grass plant to establish deeper, more extensive root systems at this key period.
Tom Wood
B.Sc (Hons) | BASIS | FACTS
