This season’s late planted potato crops, which have been slow to get going in cool soils, are expected to compensate with rapid growth as soon as conditions warm up. The rapid leaf growth is predicted to coincide with increased blight pressure as temperatures rise.
That will make protecting the expanding leaf area with the strongest blight fungicide active, mandipropamid (Revus), more important than ever, according to Syngenta Potato Technical Manager, Douglas Dyas. “When the crop’s initial growth has been held back, the area of a new potato leaf could more than quadruple in the course of a week during the rapid growth phase,” he reported. “That can put immense strain on blight fungicide protection between applications.”
When Revus is applied it locks onto the plant’s leaf wax and, as the leaf area expands, the active moves across the surface to protect it against blight infection. The fungicide is inherently very effective against blight spores, helping to ensure protection between sprays, even where application may be delayed in a difficult season. Over many years of independent trials across Europe Revus has consistently proven the most effective active in protecting against foliar blight. “When comparing results across Europe it’s essential to look at the strains of blight growers are facing,” highlighted Douglas.
“In Finland, for example, they too have picked up the A1 Pink 6 strain we have in the UK. In trials there the Revus-based programmes reliably performed the best at keeping the crop clean.” Douglas added it was clearly evident that where the early Revus-based programme had completely kept blight out of the crop, it remained clear for longer when the trial applications finished, compared to a fenamidone + propamocarb and fluopicolide + propamocarb early programme, where blight established sooner and developed faster, despite relatively low levels of blight infection.
“The trials have confirmed the importance of the early blight sprays when potato plants are growing rapidly. Whatever the blight pressure, growers cannot afford to risk letting disease establish in the crop. “Investing in strong blight performance early season pays dividends in producing a cleaner crop at the end,” he added.