Fusarium risk rising for October

October weather patterns typically see the serious onset of the UK’s most damaging turf disease, Fusarium Patch. Early reports are that the pathogen has rumbled along through the relatively cool and dull summer conditions, with potential to flare up when triggered by rainfall and changes in temperature.

A review of last year’s rainfall and temperature and the Fusarium disease risk incidence - available free on the GreenCast website, www.greencast.co.uk - reveal the close correlation between weather patterns and the disease (Fig 1, right), in this case for Rugby in the midlands.

If, in this instance, Heritage fungicide had been applied proactively when the risk of Fusarium was predicted to increase significantly in the wet and warmer weather  - at the end of September or on the 24 October - spores landing on the leaf would have been stopped from germinating and leaf damage prevented. An application on 12 October, however, would have seen the most potent first two weeks of fungicide activity wasted at a time of little or no disease pressure.

If spraying conditions had prevented application until a couple of days after the prediction of high disease risk, then using a fungicide with greater curative activity, such as Daconil Weather Stik, could still stop disease developing before any signs of infection breakout, especially as growth slows and contact fungicides come to the fore.  

For even greater flexibility at an often difficult time of year, products with a dual mode of action, such as Banner MAXX, or the multi-active fungicide, Instrata, give both curative and protectant activity to stop further disease development and keep surrounding turf clear of infection.

The typically high rainfall for October, along with the large diurnal range of day and night temperatures (Table 1), highlights the potential risk for Fusarium and the difficulties for spraying. The GreenCast weather information includes a five-day spray window forecast, to help operators schedule spray timing more effectively.   

Washed out fertility

This season fertility has been one of the major challenges posed by the intermittent heavy rainfall, with dramatic peaks and troughs in turf growth. Whilst many turf managers would have traditionally completed their fertiliser programmes by October, this season a further top-up application may be required to satisfy turf growth during any period of mild weather through the autumn.

A growth spurt after heavy rainfall can put turf under excessive stress, especially if available nutrients have been washed out. Maintaining turf in growth regulation with Primo MAXX can minimise stress on plants and create more consistent playing surfaces throughout the season. Used in conjunction with a planned fertiliser policy will keep turf in the best of health.

As the weather cools and turf growth slows, plants that have been held under Primo programmes through the summer can be gradually allowed to come out of regulation for the winter, using a final application of half-rate Primo MAXX towards the middle of October. Sports pitches in sheltered stadiums or with under soil heating, where growth can continue throughout the winter, may be held in growth regulation to maintain quality and extra strength.