Potato growers are being urged to take anti-resistance measures more seriously, especially in the light of the more aggressive blight populations and the appearance of both late and early blight.

“The blight pathogen is notorious for its ability to develop resistance to single-site fungicides and the new aggressive A2 blight strains, with their rapid reproductive cycle and ability to thrive at lower temperatures, could cause more of a problem when it comes to resistance,” explains Dr. Dominic Lamb, UK and Ireland Business Manager for Gowan.image expired

He advises growers to adopt a resistance management strategy, by integrating blight fungicides with different modes of action and with multi-site activity into their blight control programmes.

“Electis contains two actives; zoxium^®, which works on a unique site of action distinct from other blight products, plus mancozeb which works on several different sites within the fungus. The unique combination of actives offers a particularly strong anti-resistance position as well as proven foliar and tuber blight activity,” points out Dominic.

John Edmonds, European Technical Manager for Gowan, reports that there is no known resistance to Electis and no shift in its status since its launch ten years ago. “Mancozeb has seen no signs of resistance for nearly 50 years!  The low resistance risk of Electis is demonstrated by its label, allowing up to ten sprays in any one season. It controls all blight races and strains, including the new A2-13 genotypes and those resistant to phenylamides.”

Fungicide Resistance Action Group (FRAC) defines 5 sites of action for potato fungicides and zoxium offers one out of this limited number of possibilities. “By including this unique active in your blight programme, growers can take advantage of all available sites of action and minimise any future risk.”

“Although it does not have a full recommendation in the UK yet, Electis has proven activity on Alternaria or early blight in potatoes in some European countries including France, where it has a label recommendation, and The Netherlands where it is very highly rated. Electis has a two and half star rating out of a scale of three in the listing issued by the Dutch Crop Protection organisation (PPO), making it the best mainstream product for Alternaria. There is a lot more concern about Alternaria in the UK in the last few years and this new disease has already been found in the popular varieties such as Markies, Saturna or Estima, probably associated with the warm conditions. It has become a more significant disease because of changing weather conditions and also changing fungicide usage, with lower mancozeb usage in the programme overall,” he says.

“But Alternaria rarely appears in isolation and, as late blight is the primary disease by which fungicide programmes should be driven, it must be tackled with a fungicide that offers proven activity on both diseases, early and late blight. As many growers in Europe will testify, Electis has been used successfully against both blights for a number of years,” explains John Edmonds.

“The continental climate favours Alternaria over Phytophthora (or late blight) and, if our temperatures continue to rise, we are likely to see more Alternaria in our crops in the future. Realistically applying a fungicide solely for the control of Alternaria is just not practical or cost-effective in the UK, however. Growers need a fungicide with excellent and reliable activity against both late and early blight plus proven activity against foliar and tuber blight and resistance protection - Electis delivers all this,” says Mr. Edmonds.