The recent heatwave produced the earliest harvest for Irish farmers in 30 years, but also left some European countries with the worst harvests since the 1940s.
Wheat production is down by about 10 million tonnes, or 10 per cent, in the EU, while the US department of agriculture has reduced its forecast for this year's global grain harvest by 32 million tonnes because of the European heatwave.
The UN's Food and Agriculture Organisation (FAO) has warned that the shortage of grain and rising food prices will have a severe effect on some economies.
Some east European countries which would have exported large quantities of grain will now have to import grain at higher prices. The wheat crop yield has fallen by 75 per cent in Ukraine, while French and German farmers have seen a collapse in yields.
The FAO has also warned that flash floods are likely to affect parts of Europe soon, hitting farmers a second time.
The shortage of grain means that Irish tillage farmers could receive from €8 to €10 more per tonne this year, according to Teagasc.
This would help to compensate for the disappointing wheat yields, said Mr Jim O'Mahony, Teagasc's chief tillage adviser. While it was a good harvest for oats, and fairly satisfactory for spring and winter barley, the wheat yields were disappointingly poor, mainly because of bad weather during the sowing season, he said.
Mr Gary McCarthy, chairman of the Irish Soft Fruit Growers' Association, said there had been "huge demand" from supermarkets for Irish-grown fruit all summer, and that was continuing into the autumn.