Sports Turf Agronomy Advice - November 2023

Conditions changed in October and there was a definite shift away from late summer and autumn to wet and wintry weather. The reduction in available sunlight and the plants' ability to photosynthesise in conjunction with decreasing temperatures creates a reduction in growth rate. ​

These factors favour competition from moss, algae and also fungal diseases; being aware of the potential for ingress and putting plans in place to help minimise this will keep surfaces in good conditions. One of the main fungal diseases in the UK throughout this period is Microdochium nivale.

Looking at the weather in October from across the UK shows we had an average of 70% growth potential (GP), which is very similar to last year's 71.75% and is now down from high to medium GP. When conditions are particularly wet, as they have been throughout October, and the ground is soft, it causes issues for maintaining mowing practices whilst there is still active growth, but areas are unreachable with mowing equipment. Last November, conditions were relatively mild with temperatures still in the low teens, which meant there was disease pressure but also conditions for continuous growth and recovery.

An overview of the weather statistics for October can be found below. 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-2023

Unfortunately, the wet weather from the end of October is forecast to continue into early November, giving turf managers no respite. Surfaces at saturation point will be largely inaccessible in terms of maintenance. Furthermore, free draining sites will be faced with surfaces being washed out of nutrition and therefore, once presented with a gap in the poor weather, consider an application to replace any nutrition that may have been leached through the profile. Temperatures in November look consistent with the time of year with highs of early teens, but importantly the lows are mid- single figures, with only 3 nights under 3°C. This will mean soil temperatures remain favourable for some growth which will allow for some recovery of damaged and worn areas.

Water management

At this time of year, maintaining an appropriate water/air ratio is a key factor in minimising turf stress. Unfortunately, given the recent high rainfall, this is particularly challenging and there are not many drying opportunities. It also means that leaf wetness is at an almost constant throughout the day and night, further increasing disease pressure. Penetrant wetting agents are a valuable tool to help try to manage moisture levels in the rootzone. When weather conditions allow, keeping surfaces and the soil profile as dry as possible will help to reduce disease pressure and minimise any 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, having an adequate free draining material or drainage system to aid water movement away from the upper 'soil' zone in the profile and into the main drainage system, and away from the playing areas. Issues commonly arise where the means for efficient water movement away from the surface does not exist. Following a sufficient amount of rainfall, a large volume of water is taken into the surface, which cannot efficiently escape, and water levels can build up, thus creating wetter surfaces and conditions you were aiming to avoid.

Leatherjackets

Applications of Acelepryn should now be complete for most users, following 4 weeks after peak flight, as Acelepryn is most active on the 1st and 2nd instar larval stages. As with an integrated approach to disease management, monitoring, record keeping and understanding of the pests organisms' life cycle are key factors for success.

Worms

The recent rise in moisture levels through October has meant that earthworm casts have been a serious issue for most of the month for many, and will continue to be so with the current conditions. They are a major factor in the 'damage' to turf playing surfaces, which impacts on playability and visual presentation. Because there are no registered products to offer control of casting worms, damage limitation is the best-case scenario. Cultural management, using a variety of methods to reduce the food source and create an unfavourable environment, will help minimise activity and disruption to surfaces. Over-application should be avoided when trying to find a solution, as it may lead to another problem with negative effects on plant health throughout the rest of the year.

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