MELBOURNE: Australia has dropped the British-made Dukes ball from its 2020/21 Sheffield Shield season and will use only the Kookaburra to encourage more spin bowling on home pitches, Cricket Australia said on Thursday. The Dukes were introduced to the Sheffield Shield in 2016/17 to help prepare Australia's batsmen for the ball used on English pitches in the leadup to the 2019 Ashes. Tim Paine's Australia retained the urn on English soil last year for the first time since 2001 with a 2-2 draw in the five-Test series. CA's Head of Cricket Operations Peter Roach said it was the right time to revert to exclusive use of the Kookaburra for the first-class competition. Agencies