3 May 1996

Protectant for blight option

EARLY season blight control can be just as effective from a protectant fungicide as from a systemic, according to work at the Scottish Agricultural Colleges Auchin-cruive site.

During early-summer days of peak growth, a plants leaf area can increase by 15 times a week, so any active ingredient is dispersed over an increased area. In two years of trials Shirlan (fluazinam) has proved to be highly effective against blight spores, even at very low concentrations, says manufacturer Zeneca Crop Protection.

"During very rapid crop growth, the best approach is short intervals between applications, irrespective of the product used. Shirlan may be applied at intervals as low as seven days if necessary," comments Zenecas technical service manager Ray Tucker.

The unique multi-site action also virtually eliminates the chance of any build up of fungicide resistance, the company claims. And other work shows that even after a real downpour – 10mm rainfall in 16 minutes – performance did not suffer, adds Mr Tucker.