Sports Turf Agronomy Advice - November 2022

Tom Wood B.Sc (Hons)in General Interest

As we start November, we enter the period where the balance shifts towards the more undesirable factors and away from those conditions which benefit the grass plant. This is mainly because there is less available sunlight for photosynthesis, with lower temperatures creating a reduction in growth rates and prolonged leaf wetness because of less dry down time throughout the day.

The average daylight hours for the month are 8.57 hrs, down from 10.47 hrs in October, with an average of just 65 hours of sunlight for the month. These factors favour competition for grasses from moss, algae and fungal diseases. One of the main fungal diseases in the UK throughout this period is Microdochium nivale.

Weather

Across the UK, October saw more rainfall than September with 115mm compared to 84mm respectively. With regards to the amount of base nitrogen required by the plant, this was on average 5kg/N/ha less in October compared to the previous month. Growth potential moved from a high growth potential zone into the medium growth potential zone, with an average 71.75GP% for the UK and accumulated GDD (Growing Degree Days) was lower with 324GDD in October compared to 378.5GDD in September. As for temperatures, we experienced a degree drop for both maximum and minimum temperatures, and as we head through autumn into winter expect these to drop significantly further.

Click here if you want to review weather data in your region for October. To keep up to date with the weather throughout November visit https://academy.agrovista.co.uk/category/weather

Growth has remained constant through October, providing those who have carried out late season renovations with much needed recovery; although conditions have become much wetter this month, meaning that surface moisture levels are now high as we go into winter which will require careful management to ensure surfaces remain in the best condition possible.

Most fertiliser applications for the majority of venues will have now been applied, with any further applications being for plant health purposes as opposed to being applied to create any significant growth. Excessive growth at this time of the year can create soft tissue which is weak and therefore more susceptible to disease outbreaks. Any fertiliser applications should now only include minimal amounts of nitrogen, which will provide small amounts of growth as conditions allow, and which will help to aid recovery from wear and any disease scars. Biostimulants can be used to maintain plant health for as long as possible, and whilst conditions remain relatively mild they will continue to provide benefits.

With showers forecast throughout the month, maintaining an aerobic soil for as long as possible will be key. Many beneficial microorganisms thrive in a balanced soil with adequate levels of available oxygen. It is important that we ensure our soils are not depleted of this essential element and we keep them as oxygenated as possible. This can be achieved by carrying out aeration practices at the appropriate time and in the most suitable ground conditions. Taking machinery over surfaces when conditions aren't suitable will cause more damage than bringing benefits, and sometimes the hardest decision is to stay off the turf.

Water management

Maintaining an appropriate water/air ratio is a key factor in reducing turf stress during periods of the year when rainfall increases, and drying opportunities are reduced. Penetrant wetting agents are a valuable tool to help maintain moisture levels in the rootzone. By keeping surfaces and the soil profile as dry as possible, it will help to reduce disease outbreaks. When using this type of wetting agent technology, the most success is achieved when there is somewhere for the water to escape. Essentially the wetting agent allows water to flow into the rootzone evenly across the surface. Once in the profile, an adequate free draining material or drainage system will aid water movement away from the upper profile. Issues can arise where the means for efficient water movement away from the surface is not in place, and therefore after an amount of water is taken in which cannot escape, water levels can build up, creating wetter surfaces and conditions you were trying to avoid in the first place by using this type of product.

Pests

Leatherjackets

The Emergency Authorisation for Acelepryn for control of leatherjackets comes to an end this month, with the last date for application of the product on the 18th of November.

For those that have not applied the product yet, to aid effective timing of treatment, follow Syngenta guidelines (7 point plan) for application one month after peak flight is observed. Where chemical control is not authorised, entomopahogenic nematodes can be applied with warm soil temperatures and available moisture being ideal conditions to get the best out of an application. The entomopahogenic nematodes swim in the water film on soil particles in their bid to search out a larval host, useful information can be found on this link https://www.pitchcare.com/shop/sportnem-t-leatherjacket-killer-5000-m-sup-2-sup.html

Worms

With the increased soil moisture content, worm activity has increased. There are still no legal controls for earthworms and any product which is applied to directly affect them is done so illegally. Cultural management continues to be the only route currently available, which can include a combination of practices such as localised surface acidification, removal of grass clippings to reduce their food source and sanding of surfaces to assist in the drying out and dispersal of casts, leading to less negative lasting impression on the surface from the cast.

Tom Wood
B.Sc (Hons) | BASIS | FACTS