With warmer drier summer weather turf managers must be on the look out for the first symptoms of Take-All, warns Simon Barnaby of Syngenta. Turf on recently constructed sand-based greens, tees and sports pitches has proven especially susceptible already this season, he reports, but a number of management practices are likely to have increased the risk on turf surfaces that have not shown the disease in the past.
“Take-All thrives in low fertility situations, especially where the pH is higher and particularly if there is any manganese deficiency,” he advises. “With rainfall well above average in March, April and May, any residual nutrients in the sand rootzone could have been leached away, along with available manganese essential to reduce the effects of Take-All.”
Furthermore, the increased use of non-acidifying fertilisers and irrigation with naturally alkaline water has caused a dangerous rise in pH in the surface layer of some soils. Soil sample reports reveal even on greens with a pH of 6 in the rootzone, can be as high as 8.5 at the soil surface where Take-All can develop.
Mr Barnaby advises that Heritage is the only fungicide approved for the control of Take-All. On turf surfaces where there is a history of the disease, turf managers may opt for preventative applications during high risk periods. But he adds that on other turf, treatment at the first signs of disease can prevent further spread and minimise visual damage or die-back that would affect playability.
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