Sports Turf Agronomy Advice - July 2025
Half-way through year already and it has flown by. I have had a few people remark that it already feels like we have had summer, given all the good (dry and sunny) weather we have already had up until this point.
Although, from a turf managers perspective that has clearly brought with it some challenges. June was warmer and more extreme than typical Junes, driven by two back-to-back heatwaves, high-pressure “heat dome” formation, and record temperatures near the 35 °C mark in some areas. Regional contrasts were stark, hot, dry in the south, whilst, cooler, wetter, stormy in the North-west and Scotland. These patterns align with the current broader climate trends of more frequent, intense summer heat events which are expected as the effect of climate change continues.
Although the rainfall events this month have eased some drought stress pressure, the ground is still very dry and in a deficit in many areas, meaning any rainfall we do get is barely getting into the profile. This has continued to restrict good growth with many reporting that annual meadow grass growth has not really got moving all year. Not as much of an issue for winter sports managers with perennial ryegrass swards, although the issue of water usage is one that we will all need to mindful of going forward as restrictions and regulations potentially change.
Looking back at the figures from June, GP reached above 90% for 3 out of the 4 weeks recorded, although clearly moisture is still the limiting factor in some managed areas. Winter sports renovations have made excellent use of the conditions, however obviously managing new seedlings through these spells of high temperature needs to be done carefully.
Weekly nitrogen requirements are now getting towards on average, 5kg per week, although this needs to be balanced with the stress on the grass plant and its ability to grow under these conditions. GDD following the 0°C growth degree days model is now past 1,500 days, when applying PGR’s it is important to make applications in line with growth and stress.
Click here to review weather data in your region for June. To keep up to date with the weather throughout July visit https://academy.agrovista.co.uk/category/weather
After the hot end to June, the forecast for early July is cooler, with temperatures dropping to around the 20°C mark, the forecast also appears to be fairly unsettled for the remainder of the month. With periods of rain breaking between periods of sunshine. Making the most of any rainfall that we do receive will be crucial for ensuring consistency of playing surfaces and avoiding any cases of localised dry patch. A timely application of wetting agent and regularly checking moisture levels will allow for any areas that may have become hydrophobic to be identified.
Just as important at this time of year is plant health and conditioning. Ensuring the highest health possible to minimise the opportunity for disease development. Particularly, given the weather we have had up to now, anthracnose (Colletotrichum cereale) at this time in the season.
Hot, 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. The weather forecast in July does not appear to fit the trend for further anthracnose development. However, it is important to be watchful as the trigger may have occurred in the hot conditions experienced in May and June and may make an appearance in July.
Biostimulants
Applications of seaweed will elicit important beneficial defence and stress responses in the plant and associated micro-organisms when applied at times of turf stress. Ascophyllum nodosum is a good seaweed source as it must deal with tidal stresses. Half its life is spent under water and half its life out of water. Amino acids also play an important role in abiotic stress tolerance, helping plants to prepare for and cope with additional stresses such as varying changes in temperature and volumetric water content. They are also excellent at ensuring nutrients get into the plant, therefore through dry periods where every part counts they can be a useful addition to tank mixes to ensure efficient uptake of products.
Calcium and Potassium are both key nutrients when considering biotic and abiotic stress due to their role in cell walls and water regulation. Therefore, look out for these when selecting your fertiliser.
Pests
We are entering peak chafer grub activity, with some already reporting peak flight, so it is important to regularly monitor and record any activity so that informed decisions can be made about the best time to make any product applications. Entomopathogenic nematode applications can be made on sites where the label does not permit an application to cover the whole problem area with Acelepryn.
Tom Wood
B.Sc (Hons) | BASIS | FACTs