This summer's heatwave is set to give a record fruit crop, but the grain harvest is likely to be badly hit.
The wheat has wilted in the current hot conditions
The hot weather has helped growing conditions for fruit, with supermarkets reporting high demand.
However, the temperatures mean the grain harvest will be earlier than normal, resulting in a smaller yield.
The National Farmers' Union has warned that shortages of crops such as wheat, which has wilted in the heat, could result in higher prices for consumers.
Most arable farmers are in the middle of harvest, which is thought to be the earliest since 1976.
Some crops, like barley, have benefited from the heatwave, but wheat has wilted in the intense conditions.
Sandra Nichols of the NFU said: "For wheat, we're seeing at the moment that the lack of moisture in the soil has caused problems in terms of the quality of the wheat.
"The grains are thinner, the yields are not so good, and that could lead to higher prices."
Apples will not be picked for about another month, but farmers say that judging by the berry crop so far it looks like being a record fruit harvest.
Adrian Tatum of Grower magazine said the hot weather means "excellent" production for fruit such as strawberries.
"Demand is higher this year at consumer level, the retailer is demanding more British strawberries, so the hot weather helps in that production flow to meet demand," he said.
Among supermarkets reporting high demand was Sainsburys.
Compared to the same week last year, this week saw a 45% increase of sales of melons and exotic fruit, 20% up for soft fruit - such as strawberries, raspberries and blueberries - 40% rise for stoned fruit, and 35% for tropical fruits, such as grapes and pineapple.
"We have had fantastic sales of summer fruits," said a spokeswoman, who added salads had also seen a growth in sales.
Last week the retailer sold more than two million packs of tomatoes - 28% more than the same time last year - and 1.3 million cucumbers, a rise of 34%.
BBC News business correspondent Hugh Pym said a hotter climate in the UK could encourage the growing of less traditional fruit, such as apricots, in the future.
Meanwhile, the leader of the National Farmers Union in Wales, Dai Davies, said the shortage of grass meant farmers were having to feed winter stocks to cattle now.
"So there's no margin, no money in the kitty for the purchase of winter fodder which we shall need to survive," he told BBC News 24.
"So there's great concern about what happens in the autumn."