Acid clouds, secret payouts and protecting the brand of New Zealand apples are at the centre of a $1 million claim against New Zealand's largest fertiliser manufacturer.

Napier orchardist Paddy Donovan has taken Ravensdown to the High Court over claims that he was not paid compensation for acid and fluoride damage caused by the company's Awatoto plant outside Napier. A 12-day hearing before Justice John Wild began in Napier yesterday.

Airborne discharges from the plant, built in 1954, have long been a source of controversy in Hawke's Bay. Acid and fluoride discharges have affected nearby crops and Ravensdown has made confidential payouts to various growers for the discharges since the mid-1990s.

Several prominent apple producers, including the country's largest, Mr Apple, have been called as witnesses for Mr Donovan.

His lawyer, David O'Connor, told the court that the companies had also suffered crop damage but had shied away from making a claim as "their brand is more important than a claim".

In November 2004, Ravensdown paid Mr Donovan $223,003 for damage caused in the 2003-04 season, but has not paid for damage in 2004-05 and 2005-06.

Mr Donovan is seeking a further $862,635 for losses to crops in those seasons, plus general damages of $25,000 for distress and anxiety, and $50,000 in exemplary damages.He is also seeking compensation for the loss of value to his land - but has not provided a figure, claiming that an estimate on value would best be made after the trial.

The company's lawyer, Rob Osborne, opposed this, saying the claim should be the subject of a separate trial.

Ravensdown refused to accept liability for the damage caused in 2004-05 till Friday, when it accepted blame, but disputed the value. It accepted some liability for damage in 2005-06, but not damage that occurred in late January 2006, which it maintains could have been caused by other factors.

Mr O'Connor said 23 witnesses would be called, including neighbouring orchardists who would describe "Ravensdown's position of refusing to accept responsibility, blaming the growers but making confidential settlements".

Mr Donovan, who grew up on the orchard, told the court he had noticed damage to his crops for years after the plant was built, but had not known others were suffering the same damage.

It was not till the 2003-04 season that he discovered some of his neighbours had been compensated by the company.

He stopped growing fruit in 2006 because of the losses suffered. He has leased the land to Enza since.

There have been no reports of damage to fruit near Ravensdown in the past two years, which Mr Donovan put down to a lack of easterly winds and a big decrease in the amount of acid being discharged from the plant.