Sports Turf Agronomy Advice - September 2022

This month traditionally sees a shift in weather conditions, which become more autumnal without extreme heat and long dry spells (location dependant) which can cause issues through the height of summer, and there is typically more moisture around which really helps drive seed germination, establishment and growth.

Mornings and nights become noticeably darker and, importantly for turf managers, dew on the grass plant becomes a more regular occurrence.

Weather

Taking a deeper look into the weather across the UK from August shows we had an average of 91% growth potential (GP) which was less than the previous month of July. Temperatures remained consistent with 24°C AVG highs and 11.4°C AVG lows. We did not encounter much rainfall during the first 2 weeks of August, but soon caught up (location dependant) with an overall UK average of 89mm falling. Base nitrogen requirements also remained consistent with previous years, with an average of 27kg/N/ha required.

If you want to take a deeper look into your regional weather for September please click here and to keep up to date with weekly amenity weather forecasts for September, visit https://academy.agrovista.co.uk/category/weather.

The forecast for September looks set to break from the typically dry weather we have been experiencing in most parts of the country. The start of the month looks unsettled with spells of rain forecast for most of the first two weeks. Towards the end of the month, it is forecast to settle down with less frequent showers. Temperatures start the month in the late-teens, but towards the end of September these are predicted to be lowering to the mid-teens.

The increased rainfall and conducive temperatures could mean those who are yet to carry out renovations still have a good opportunity for success this month, providing the rainfall is not too extreme. If overseeding work is being carried out, ensuring a good contact with the soil will allow the seed to utilise the moisture in the ground. Also, consider utilising plant growth regulators, such as Prohexadione-calcium and trinexapac-ethyl, to help in the development of new seed by holding back the competition from the existing mature plants in the sward, creating a more favourable environment for establishment.

Disease

Conditions can become more suitable for disease development in September with an increase in moisture levels in both the soil and on the leaf surface. The 3 constituents of the disease triangle combine and surfaces can become damaged. This month can be an appropriate time to put in place a preventive disease management plan. This will ideally be an integrated approach which includes carefully selected nutrition from an appropriate nitrogen source (one that isn't going to contribute to disease development), fungicides, biostimulants and moisture management, including dew control. These can be utilised in a synergistic approach where each application complements the next in the effort to minimise disease outbreaks and maximise plant health.

Pests

We are still awaiting confirmation for the Emergency Authorisation for Acelepryn for control of leatherjackets. This has previously applied to golf courses, airfields and racecourses only. If emergency authorisation is approved, further details on application timings will be available.

Adult crane fly typically emerge in late July through to September. The adult flies commence egg laying almost immediately, with hatching and larvae emergence about two weeks later. You can check reported sightings of crane fly species on the Pest Tracker (https://www.greencast.co.uk/turf-pest-tracker) on the GreenCast website. To aid effective timing of treatment, ensure the product is in the soil at the optimum time for egg hatch and initial larvae activity. 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

The Acelepryn application window for control of adult Chafers has now passed and should have been completed by 28th August.

With the increased soil moisture content in September, worm activity will increase and soon become a major issue for turf managers. 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