Met Éireann has today (Wednesday, June 19) issued a Status Yellow advisory for potato blight in several counties over the coming days.
Weather conditions conducive to spread of blight are expected to develop in counties Donegal; Mayo; Galway and Kerry from early on Friday persisting through to Saturday morning.
The national meteorological service said that there are opportunities for spraying today.
Potato blight
Copa Cogeca, the umbrella group of European Union (EU) farm organisations, previously said that a “European action plan to combat late blight in potatoes is needed”.
It has said the annual economic damage in the EU from potato blight is estimated at around €900 million.
The blight causing pathogen, Phytophthora infestans, infects both the foliage and tubers of potato plants and can devastate the entire crop within just one or two weeks.
This pathogen is highly adaptive, and recent developments show that it is evolving more complex virulence spectra, enabling it to overcome an increasing number of resistance genes.
Teagasc is also urging all Irish potato growers to fundamentally change their potato blight spraying programmes with immediate effect.
This reflects the growing influence of resistant blight populations, both in Ireland and across Europe.
Dr. Steven Kildea, Teagasc potato specialist, said that blight populations are evolving at a faster rate than ever.
As a result, he said that “the days of block spraying for blight are over”, adding that crops should be sprayed at seven-day intervals.
“The future will be shaped around a strategy of mixing two different blight chemistries in the one tank and ensuring that modes of action, where blight fungicides are concerned, are changed in sequential spray applications,” he said.