Nelson apple growers assess that they may have lost up to 10 per cent of their 6 million carton export apple crop in hail storms last week.

The first storm struck on Tuesday and insurance companies are visiting growers to quantify damage.

Some growers in the Nelson area have lost almost all their fruit while others have escaped completely unscathed.

Press reports from New Zealand indicate that losses could be even higher as later storms may have caused further damage.

The news comes following spring frosts in September and October which have struck North Island production in the principal Hawke's Bay area hard also reducing likely export volumes from that region.