The number of kiwifruit orchards testing positive for PSA continues to climb, with Zespri confirming 61 infections by the end of Monday.

Despite the growing toll, the exporter is bullish about next season’s crop volume, which it doesn’t expect to be affected.

Zespri Director of Corporate and Grower Services Carol Ward says the spread of PSA is still within the variation of seasonal production.

“We might expect, within a season, to get variances in production levels of around five or even up to ten per cent depending on various factors like weather.

"At this point in time we’re absolutely confident from what we know now that we should have a good crop for next year."

Ms Ward says some of the infected orchards have only minimal spread.

"They represent around one per cent but what we have in those orchards are varying degrees of spread.

"In some they may only have one or two vines infected, whereas in other cases it’s more widespread. So that one per cent is an absolute maximum.”

Zespri sold 98.5 million New Zealand-grown trays in the season just finished.

It’s total turnover was $1.5b.