However, whether these higher prices are passed on to farmers struggling with the rising input costs, or snaffled by middlemen further along the supply chain, remains to be seen, according to Growcom chief executive Jan Davis.

Ms Davis says fertiliser and chemical prices alone comprise between 11pc and 14pc of total farm input costs.

"Fertiliser prices have more than doubled in the past year - and the price of urea has increased more than 25pc in the past month alone," she said.

"Growers are concerned that limited competition in the fertiliser supply industry is creating a situation in which prices can be manipulated."

Ms Davis says the only way farmers have survived this long is through efficiency gains, but says there is now little further capacity in the industry to "absorb continual price increases of the magnitude we are seeing now".

"Consumers who have enjoyed relatively inexpensive locally grown fresh produce for years may not like the suggestion, but farm businesses have to cover their overheads as much as any other business or fail," she said.

"In the face of increasing world food insecurity, governments will have to weigh up the costs of local horticultural businesses failing in terms of the long-term health of the population no longer able to prevent chronic disease through the consumption of locally produced fresh fruit and vegetables.

"The impact on domestic food security and the implications of greater reliance on imported food supplies must also be seriously considered."