The continued locust plague may become the biggest threat to the nation's grain farmers as it may possibily infest the areas from Birdsville to Bendigo.

According to the report by the Australian Bureau of Agriculture and Resource Economics, more than 450,000 hectares is in dire need of spray to stop crops from being infected.

The warning came on Wednesday at the same time that two United Nation agencies predicted a possible 70 per cent hike in food prices over the next 10 years.

The forecast by the Organization for Economic Co-Operation and Development and the Food and Agricultrue Organization explained that wheat and coarse grain prices may increase to 15-40 per cent while oil prices will surge up to 40 per cent.

Meat and livestock products are expected to exceed the 1997-2006 average supply in the coming years because of lower supplies, higher costs and rising demand.

Predictions for beef and pork prices may increase by 21 per cent and 17 per cent respectively, while poultry famrs may jump up to 32 per cent by nine years.

Dairy products are also expected to increase up to 14-45 per cent from 2010 to 2019.

Despite locust infestations and rising of food prices, Australian farmers is predicted to enjoy a 22.1 million tonnes of wheat harvest this summer, which is 2 per cent or 440,000 tonnes more than what was generated last year.

At least 35 million tonnes of cereals, including meat, barley and canola, may also be harvested this summer.