South Africa captain Laura Wolvaardt has called for a major improvement from her team following their warm-up loss to New Zealand, warning they cannot afford to "go through the motions" against Australia in Saturday's Women's T20 World Cup clash.

The Proteas managed a narrow win over Ireland but then suffered a five-wicket defeat to the defending champions New Zealand. Now they must raise their game against six-time champions Australia.

Wolvaardt called the loss a wake-up call, insisting the team needs sharper strategies and a much better performance against Australia.

"We would have liked to win both warm-up games, but maybe this is exactly what we needed before the tournament starts," Wolvaardt told ICC.

"Just a little eye-opener that it won't just happen automatically. We can't go through the motions with the ball. We came up against a quality side, and they outsmarted us with the bat.

"So we need good strategies in place for the Australia game, and hopefully we can turn it around," she added.

On a positive note, Chloe Tryon smashed an unbeaten 61 off just 26 balls, including six towering sixes. Wolvaardt believes Tryon could be South Africa's X-factor at the World Cup.

"That innings was awesome," Wolvaardt said.

"It's been a while since she struck the ball that sweetly. She held her shapes really well and was hitting nicely through the line. It's hard to stop her when she's in that form.

"She was hitting balls from outside leg stump over covers for six. It's great she has found some form before the tournament," said Wolvaardt, who is just two matches away from 100 T20Is.

Defending champions New Zealand head into the tournament with two warm-up wins. They will open their title defense against the 2016 champions, the West Indies, in Southampton