'If potatoes don't get water within the next fortnight, we are looking at a very significant crisis'
The heatwave, which follows an extremely wet April, has played havoc with the production of spuds.
Angus Wilson, who set up Wilson's Country Ltd in Armagh 40 years ago, said the crop of Comber potatoes currently being harvested is much less than it should have been.
He warned that if it doesn't rain within the next week, the crop sown in May and due to be lifted in September will be in even shorter supply.
Mr Wilson said: "The early crop of Comber potatoes, which are being dug at the moment, is maybe half of what it should be and the rest of the crop is really, really thirsty.
"If they don't get water within the next fortnight, we are looking at a very significant crisis in the industry for next year's crop.
"Normally, Comber potatoes would yield around six or seven tonnes an acre, but we are looking at half that now.
"The main crop of potatoes that were planted in May are doing quite well, surprisingly, in spite of the drought, but that's because they don't need a lot of water at the initial growing period. But from here, going forward, a lot more water will be needed.
"If it doesn't rain within the next two weeks, we will be very concerned. In the 30 years since I started the business, I certainly do not remember conditions as hot and dry as this."