Move Electis into blight programmes now!

UK - June 17, 2005

As early planted crops reach the full canopy stage and blight pressure mounts, Dow AgroSciences is advising potato growers to incorporate strong protectant foliar fungicides which also offer strong protection against zoospore production and tuber blight, such as Electis, into their blight programmes from now on.

"During the critical mid-season period, blight sprays must provide protection of the canopy against foliar blight, offer good tuber blight protection, have a strong anti-resistance position and be highly rainfast.  Products such as Electis provide all the necessary criteria for a mid-season and late-season spray and growers should be integrating this product into their blight control programmes from now on.  Based on a novel active ingredient, zoxium, combined with mancozeb, Electis is a strong and effective protectant fungicide, outperforming fluazinam and cymoxanil plus mancozeb in trials over many years.  In fact it has been categorised as one of the top foliar blight fungicides and one of the best protectants by a panel of European industry experts," comments Andy Leader, Principal Biologist for Dow AgroSciences.

"The cooler summer temperatures are ideal for the production of zoospores and so it is important this season to start the tuber blight programme early.  The choice of blight fungicide at this point in the programme can make a crucial difference to the successful prevention of tuber blight.  But not all fungicides have good activity on zoospores, the motile spores that cause tuber infection, and only a few products actually prevent zoospore production in the first place."

"Zoxium adversely affects zoospore release, resulting in the production of non-motile spores, incapable of infecting tubers.  Other fungicides such as cyazofamid and fluazinam kill zoospores once they are released and so the alternation of Electis with such complementary products in a programme will provide a "belt and braces" approach and give excellent protection against tuber blight.  This approach was confirmed last year in British Potato Council trials.  The Belchim/Dow AgroSciences manufacturers' programme, consisting of two treatments of Epok (mefenoxam plus fluazinam), followed by Electis (zoxium + mancozeb) alternating with Ranman TP (cyazofamid plus adjuvant) up until desiccation, gave the best control of foliar and tuber blight," explains Mr. Leader.

"Another important consideration at this point in the blight programme is resistance management.  Electis offers a unique mode of action, distinct from all existing potato blight products.  Mancozeb is recognised as a highly effective protectant fungicide with multi-site activity: it acts by preventing spore germination.  Both actives in Electis complement each other in terms of modes of action.  Electis is the right product to include mid-season as it is multi-sited, has no known resistance and it will control all blight strains, including those resistant to phenylamides," adds Andy.

"Electis has been proven in the laboratory and in the field to be one of the most rainfast of all blight fungicides available.  Zoxium is very lipophilic, which means that it has low water solubility and high affinity for leaf wax.  It penetrates the leaf surface and then moves rapidly into the waxy layers of the leaf, becoming rainfast within one hour, highly resilient to wash off and allowing irrigation flexibility and peace of mind in catchy weather," concludes Mr. Leader.

Electis contains 8.3% w/w zoxium 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-hectare pack (5.4 kg).