Cecilia Cho and Lydia Ko start favourites to dominate a 36-strong field competing in the North Island strokeplay championships which start at Whitford Park golf club today.

World No 3 Ko, 13, will defend her North Island title on the back of some outstanding form across the Tasman where she took out the Australian strokeplay honours.

Cho, the world No 2, was runner-up to Ko in the Australian event which she won last year and was a semifinalist in the matchplay.

Other contenders in the 72-hole tournament are Queen Sirikit Cup representative Emily Perry, South Island amateur champion Jesse Hamilton, Pakuranga sisters Celyn and Caryn Khoo and the winning Interprovincial team from North Harbour, Faye-Amy Nickson, Rebecca Brownlee and Rica Tse.

In the men's tournament, New Zealand representative Ryan Fox will be back on his old stamping ground at Whitford Park.

Fox, who now plays out of the Royal Auckland club, is pre-tournament favourite in the 124-strong men's field and believes it will be a good test.

"It would mean a lot to me to win there," Fox said.

"I have a lot of friends that still play there and I have history there, playing pennants for them early on, and winning a junior club championship there.

"It would also be a huge honour to win such a prestigious tournament in the place I grew up playing."

His competition will come from national strokeplay champion Brad Kendall (Mt Maunganui), Australian amateur quarter-finalist Mathew Perry (Hamilton), Titirangi's Sam An, who won his age group at the Aaron Baddeley International in December, the 2008 national champion Thomas Spearman-Burn (Miramar), skilled North Harbour players Simon Brownlee and Cameron Jones along with the talented Royal Auckland club player, Fraser Wilkin.