Disease adds to orchard woes

CANKER CONTROL: Simon Easton inspects a tree on his Mariri orchard which has had european canker cut out.
CANKER CONTROL: Simon Easton inspects a tree on his Mariri orchard which has had european canker cut out.

Nelson pipfruit growers are battling another threat to their viability - an explosion of the tree-killing disease european canker.

Tens of thousands of trees have been pulled out in the last couple of years and hundreds of thousands of others have been infected as the fungal disease has run rampant following several wetter-than-normal growing seasons.

Industry figures, who until recently have been reluctant to publicly discuss the disease, have acknowledged it has the potential to be as serious as the Psa-V disease which has devastated northern kiwifruit orchards.

Motueka Fruitgrowers Association chairman Simon Easton said growers had been forced to rip out whole blocks of trees, some planted only three years ago. New varieties had proved particularly susceptible.

It had got so bad in hot spots like Riwaka it wasn't worth planting trees until growers could establish some measure of control, he said. There were signs it was spreading into areas of previously low infection, such as the Waimea Plains. "It's the No 1 problem in the orchard."

Mr Easton said he feared what would happen if it was wet and windy over spring, which could see the disease take off again.

It is costing growers up to $1 a carton to control and comes as many are struggling to make money after three consecutive years of losses and can't afford to replace trees.

Its rapid spread has been boosted by the intensive planting of dwarf varieties in new orchards, nurseries supplying infected seedlings and slack control measures adopted by growers in the past.

Mr Easton said efforts to fight the disease were being hampered by orchardists "growing to extinction" who either couldn't or wouldn't follow an industry canker management strategy. It had prompted the association to request Tasman District Council and Nelson City Council to declare it a boundary control pest.

Lower Moutere orchardist Ian Palmer, who stepped down earlier this month as Pipfruit NZ chairman, said if the wet weather continued it would spell the end for some growers.

"You could put it on a parallel of what Psa-V's done to kiwifruit because it has a similar effect of eliminating orchards.

"But if we get drier conditions it will slow down the spread and we can get on top of it."

Mr Palmer denied it would make it tougher for growers to get their fruit into the recently opened Australian market.

While Australian orchardists would attempt to use it as a political stick to reopen the debate over the entry of New Zealand fruit, the negotiated protocols made it clear that european canker was not an issue as long as growers stuck to the correct management regime, he said.

Science had shown that european canker was a tree disease which did not affect fruit quality, Mr Palmer said.

Orchards under threat, p11

The Nelson Mail