DOUG and Rod May have a very simple reason for not growing genetically-modified crops.

"Our customers will not buy them," Doug said.

"We sell direct to customers and talk to them every day and they tell us they are not interested. They don't believe they are safe."

They and their other brother Greg and father Maurice have worked the fertile land at Blampied for three generations, most recently supplying customers with organically grown potatoes, wine, lamb and beef at farmers' markets, the cellar door or through home delivery.

The family is unconvinced by assurances GM foods are safe and believe there are too many unknowns.

Nor are they convinced GM crops benefit the farmer.

"There have been great promises of things such as drought and frost tolerance, yield increases and higher nutritive value but very little delivered that can't be achieved with conventional crops and good farming techniques," Rod said.

The Mays are not alone in opposing GM crops, with just over half of farmers surveyed by The Weekly Times saying they were not willing to grow them.

Grain growers were the most accepting of GM technology, with 54 per cent saying they would grow GM crops but beef producers were the least likely, with only 23 per cent willing.

But Victorian Farmers Federation president Andrew Broad said it was still early days and as more GM crops with proven benefits came on to the market, farmers and consumers would become more accepting.

He said he believed biotechnology offered the potential for better crops and should be pursued.