Plan for Resistance Management, too
When planning their blight control programmes, potato growers should be taking resistance management into consideration, too, particularly in the light of the more challenging blight populations.
"The blight pathogen is ideally placed to develop resistance – it has a rapid life cycle, new more aggressive strains and multiple sprays are required to control it over the entire life of the potato crop. Resistance build up will be more of a problem for single-site fungicides and for the new A2 blight strain, which dominate populations across the UK, with its faster reproductive cycle, more aggressive nature and ability to thrive at lower temperatures. The new A1 strain is also proving aggressive in some parts of the UK. The situation should be causing concern amongst advisors and growers and they should be planning accordingly," explains John Edmonds, European Technical Manager for Gowan Comércio.
He advises that growers implement the guidelines of resistance management strictly, by integrating blight fungicides that work on different sites of action and that have proven multi-site activity into their blight control programme.
"Electis contains two active ingredients; zoxium (zoxamide) which works on a unique site of action, distinct from all known blight products, and mancozeb which works on many diverse sites within the fungus. So Electis offers a particularly strong anti-resistance position. The unique combination of active ingredients in Electis also results in proven foliar and tuber blight activity," points out John.
"Furthermore there is no known resistance to Electis and no shift in its status since its launch in 2001. Mancozeb has been around for over 45 years, with no known resistance problems anywhere in the world. Electis controls all known blight races and strains, including the new A2-13 and A1 genotypes and those resistant to phenylamides," he says.
John Edmonds reports that, according to the FRAC, there are just 5 sites of action for potato fungicides on blight and zoxium, with its unique site of action, offers one out of this very limited number of possibilities. "By including this unique active into blight programmes, growers can take advantage of all available sites of action and so minimise any future risk or fungicide resistance. If resistance were to escalate in potatoes, as has happened in other crops with multiple spray programmes, blight could really take a hold and cause significant crop losses."
"The low resistance risk position of Electis is supported by the authorities and is reflected by its label which allows ten sprays in any one season. This gives growers ultimate flexibility to integrate this fungicide into their programmes for effective foliar and tuber late blight control, for the added control of Alternaria early blight and also as robust resistance management strategy. It also makes planning much easier as many other blight fungicides, mainly for resistant management reasons, are limited to many fewer sprays per season."
John Edmonds points out "Trials and commercial use demonstrate each year that Electis is highly effective against blight and it is amongst the strongest protectants available, according to the European panel Euroblight. It also shows unique activity on zoospores, preventing their formation and release, leading to excellent tuber blight protection. Its results are consistent and programmes containing Electis appear to perform better overall."
®Electis contains 8.3% w/w zoxium (zoxamide) and 66.7% w/w mancozeb, formulated as a WDG. It is recommended on all varieties of potatoes at spray intervals of 7 to 14 days. It has a dose rate of 1.8 kg/ha in 200-600 litres of water per hectare. It has a maximum number of treatments of 10 per crop and a harvest interval of 7 days. It is packed in a 3-ha pack (5.4 kg).
