Two listed companies are the first victims of a suspected incursion in New Zealand of a bacterial canker which has ripped through gold kiwifruit varieties overseas, particularly in Italy.

Seeka Kiwifruit Industries and Satara Cooperative Group today sought a trading halt on the NZX because they fear one of their orchards has been hit by a bacterial canker called Pseudomonas syringae pv. actinidiae (PSA) which effectively wiped out a New Zealand-owned gold kiwifruit orchard in Italy earlier this year.

Some strains of the disease particularly hit Hort16a, Zespri's gold cultivar which is the most profitable of the company's exports.

"Both of those announcements are driven by that," a Satara executive at Te Puke told NZPA.

"It's a vine disease which has previously existed in other countries, I believe Hort16A is particularly subject to adverse effects from that disease."

According to Radio New Zealand, the Ministry of Agriculture and Forestry says it is 95 per cent sure the disease has been found in a Bay of Plenty orchard.

Satara and Seeka would make an announcement about the potential impact on their businesses by tomorrow morning at the latest, he said.

PSA became a serious problem in Zespri's Hort16A (gold kiwifruit) and the Jin Tao cultivar in Italy during the last season with economic damage estimated in millions of euros, to the point that in April New Zealand grower OPAC announced it might have to write off its NewGold orchard.

Seeka is listed in the main board of the NZX, and controls 26 per cent of New Zealand kiwifruit crop, having bought out fruit packaging company Te Awanui Huka Pak for $24.2 million late last year.

Shares last traded at $3.10 before the trading halt, and had lost 1.6 per cent in value this year.

Satara, which is listed on the alternative index, announced in September that it was looking to merge with EastPack to form a wholly grower-owned company. Details of the deal, which are still pending, are expected in mid-November.

Satara shares last traded at $1 before the trading halt, and have risen 42.9 per cent this year.

Satara also has a 20 per cent stake in Opotiki post-harvest group OPAC, which in April said PSA had done so much damage to its NewGold orchard in Italy - which grows Hort16A - that it might have to write off its NewGold orchard.

The disease has caused economic damage estimated in millions of euros in Italy, and Agriculture Minister David Carter said today that urgent action was underway to confirm the Bay of Plenty infection vine infection is PSA.

MAF Biosecurity said the orchard had been quarantined in an effort to reduce the risk of the bacteria spreading. Overseas it is most commonly spread from vine to vine by splashes of rain, but it is also spread by pruners who fail to adequately clean their tools between vines.

Japanese efforts to use copper compounds and antibiotics to control the bacteria failed, when strains of resistant bacteria developed.

An OPAC executive in April that Italian efforts to control the disease by removing and burning infected vines failed spectacularly.