Potato Blight - Nufarm UK

Three ways to prevent Blight

Control of Blight in potato dumps and clamps

Potato dumps act as a primary source of Blight. Control of shoots is essential to prevent spread of Blight to the new crop

Covering the dump with black plastic is one way of preventing development of foliage and hence prevents them from becoming a source of infection for the potato crop. Plants emerging from the edge of the clamp can be treated with an approved contact herbicide

Dumps should be levelled prior to treatment

Control of volunteer potatoes with Tandus

A second source of Blight is volunteer potatoes in cereals left over from the the previous autumn. These potatoes sprout and produce an early source of Blight.

Volunteer potatoes can be controlled with Tandus. Containing fluroxypyr, Tandus will control potato shoots from 10 to 40cm in height.

Tandus can be used in cereals up to and including the boot swollen stage (GS 45)

Control of Potato Blight in the crop

This picture shows the decimating effect of Blight in a Nufarm trial. The green plot behind was sprayed at regular intervals with Matilda. Spores and disease will spread to the tubers where the real economic damage is done and there is the potential to completely destroy the crop

A Smith or Blight period is defined as a period of two consecutive days when the the temperature has not dropped below 10 degrees centigrade and the relative humidity has been above 90% for at least 11 hours

A Blight period encourages sporulation. Regular Blight periods every 7-10 days are ideal conditions for Potato Blight

Potato Blight products are generally preventative with limited curative action. A regular spray is essential protect new leaves and prevent infection. Use shorter spray intervals when Blight periods occur especially if they occur frequently

One of the most cost effective and widely used treatments for Blight is a mixture of cymoxanil and mancozeb, sold by Nufarm as Matilda. There is no recorded Blight resistance to this mixture. Unlike many Blight fungicides, these products have no LERAP requirement. Potatoes can be sprayed at a minimum spray interval of seven days until the potato haulm dies down or is desiccated

New for 2009 for the UK, Nando is a new fluazinam formulation to be sold internationally by Nufarm. Nando is characterised by multisite activity, reducing the risk of resistance and is a particularly cost-effective product for the prevention of Tuber Blight. For more information click the Nando tab in the left margin

Always read the label: use pesticides safely

Printer Friendly Page