Sports Turf Agronomy Advice - July 2023
The summer solstice came and went in the blink of an eye, and we are now at the halfway point for 2023. There has been some exceptional weather in June, which has been great for an active social life, but not necessarily so great for managing turf.
Although the weather has been warm, the significant lack of rainfall has meant drought conditions for most turf managers, which has put increased strain on irrigation systems, which have been running day in day out and, inevitably, faults have appeared for many with ageing systems. For those not fortunate enough to have a means of irrigating, it has been a very trying month indeed. Looking back beyond June, conditions haven't been particularly conducive for good grass growth this year. March was a very wet month, in April we had cold temperatures which restricted good spring growth and May proceeded to get drier and drier as the month went on, and this has continued into June, coupled with high temperatures and drying winds.
An overview of the weather statistics for June can be found below. The GP for the first week continued the upward trend from the end of May; by week two, GP was nearly 85% and has remained above 90% throughout June. Rainfall figures show how the dry weather from mid-May continued up to week 24, with only small amounts falling since.
Click here if you want to review weather data in your region for June. To keep up to date with the weather throughout May visit https://academy.agrovista.co.uk/category/weather
Looking at July's long-term forecast, temperatures are forecast to be moderate for the time of year, with only 11 days just above 20°C. Showers also look more frequent, which should mean that moisture management is less intensive and will allow irrigation systems to run less frequently. Hand watering may still play an important role through July, with automatic systems only being used when absolutely necessary.
With optimum light, temperatures and sufficient moisture being provided (in most situations), growth in July should be a steady constant, requiring minimal nitrogen inputs; where applied, it will only be to maintain enough growth for recovery. Those growing-in from seed after a renovation will be applying fertiliser to ensure the best establishment possible is achieved. Much more important at this time of year is plant health and conditioning, ensuring the highest health possible to minimise the opportunity for disease development. Particularly anthracnose (Colletotrichum cereale) at this time in the season. 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. The weather forecast in July does not appear to fit the trend for anthracnose development. However, it is important to be watchful as the trigger may have occurred in the hot conditions experienced in June and may manifest mid/back end of 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
Acelepryn has achieved full registration and does not require an emergency authorisation for applications to be made. Full details can be found in the Pitchcare update here.
There has been a label change in comparison to what was permitted under the emergency approval, so ensure you follow the guidance on the label to make certain it can be applied to your turf area. Speak to your BASIS qualified advisor who will be able to talk through the application guidelines to follow. You can also find all the relevant information on the Syngenta website here.
We are entering peak chafer grub activity, 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