A veteran farmer has warned that a month of devastating weather is set to impact banana quality and supply from far north Queensland.

Record rainfall and flooding caused by Tropical Cyclone Jasper last month still impact supply chains in Australia's largest banana-growing region.

Bananas are farmed commercially in N.S.W., Western Australia, the Northern Territory and Queensland. But the far north's Tully, Innisfail, Lakeland and Atherton Tablelands account for 94 per cent of banana growing areas.

Trucks are taking twice as long to navigate rural roads severely damaged or closed in the recent storms.

With constant rainfall and ensuing strong winds, the quality of bananas could also be impacted. Quality issues with bananas over the coming weeks could be felt due to flooding and bag rub.

The latter occurs when a protective bag that shields bananas from pests, insects, and the sun rubs against the fruit, causing abrasions to its skin and affecting quality.

The worst effects from rainfall were felt in 2011 when the most significant storm in Queensland's history hit the coastline, destroying 75 per cent of banana crops.

Two months after Cyclone Yasi, bananas were sold for up to $14.99 per kilo.