Rising temperatures have triggered the first sustained periods of high risk for Take-All on turf surfaces this season. Normally turf managers would expect such levels of pressure in June or July, but with several successive days in the mid to high 20’s°C predicted this week (7 – 10 May) the disease forecasting service www.greencast.co.uk is warning of high risk from the south east to the Scottish borders.
The risk has been increased by recent heavy rainfall, which would have washed out much of the available manganese, leaving turf more susceptible to Take-All. High pH soils and sandy rootzones will further exacerbate the risk.
Syngenta technical manager, Simon Barnaby, advocates turf managers should consider an application of Heritage when GreenCast predicts three or more consecutive days of medium to high risk; Heritage is the only fungicide approved for Take-All control.
“The aim is to target Take-All disease at the base of the plant, as well as a broad-spectrum of foliar diseases that can affect fast growing turf in spring,” he advises.
To ensure optimum results against Take-All and Fairy Ring in the base of the sward, Simon Barnaby advises sprayer operators to maintain relatively high water volumes, of at least 800 – 1000 litres per hectare. Coarser nozzles generally used to apply higher water volumes will also create larger droplets that will penetrate to the base of plants.
“With plenty of soil moisture currently available, and most turf managers having made their initial fertiliser applications, turf is now growing strongly, ensuring optimum uptake of the highly systemic Heritage that will reach foliar diseases,” he adds. “It will continue to move within the plant and protect new growth from infection.”
Simon Barnaby says that the turn to hot, dry weather has fortunately limited the activity of Fusarium Patch, but there is some risk of Dollar Spot attack in the UK, particularly in the south and eastern midlands and on irrigated surfaces.
“Where turf managers have experienced problems in the past, the addition of Banner MAXX in a fungicide tank-mix will complete the disease spectrum,” he advises.
For a free local forecast of Take-All and other turf diseases visit probably the UK’s most sophisticated turf disease decision support web site, www.greencast.co.uk