The price of Australian wool favoured by Chinese clothing makers has dropped as much as 20 per cent over the last fortnight, sales reports show, with would-be bidders shunning auctions as Trump's trade war with China ramped up.

The plunge began immediately after an announcement from Washington on August 1 that fresh tariffs on Chinese imports would include clothes and shoes, sapping wool-demand from factories in China that churn out everything from street fashions to sports gear.

Some farmers have been withdrawing their wool bales before auction in hope of a price recovery. Credit:Rob Homer

Bidding has been particularly weak in Western Australia's Fremantle auction, where more than half of fleeces are failing to find a buyer, the sales reports show. Prices have also been pressured in the country's two other big selling centres of Sydney and Melbourne.

Australia controls 90 per cent of global fine-wool exports, where prices are driven by Chinese wool mills and Italian garment makers.