The region's largest grower, Waipopo Orchards, expects to top 900 tonnes this year - up from 400 tonnes last year.
Co-owner Peter Bennett said it was the height of the picking season, and the company's packing facility was operating on double shifts for at least the next fortnight.
The entire crop would be shipped to the United States, the United Kingdom, continental Europe and Asia. About three-quarters would leave through the Port of Timaru and the rest from Port Chalmers.
Picking began at the start of last month and would continue until the end of next month, Mr Bennett said.
The apples were picked from the company's orchards and investment blocks from Seadown to Makikihi, covering a total of about 120ha. The area planted had increased from 80ha last year, and another 40ha would be planted in apples this winter.
A shortage of apples worldwide was pushing up prices but that was being partly offset by a higher currency exchange rate, he said.
Pipfruit New Zealand chief executive Alan Pollard said ideal growing conditions throughout most of the country had resulted in large, firm fruit with excellent taste.
However, the national crop was expected to be slightly smaller than last year's record 550,000 tonnes harvested and 325,000 tonnes exported.
''The big difference between 2013 and 2014 is the size.
''This year's fruit size will be bigger than the past few seasons, and this will be a point of difference for the New Zealand crop.''
The New Zealand apple industry produced 62.9 tonnes a hectare last year, compared with the next highest national average of 41.3 tonnes a ha in Chile.
''New Zealand is without doubt the best place in the world to grow apples,'' Mr Pollard said.
''Our island climate keeps summers not too hot and winters not too cold, perfect for apples.''
- by Guy Williams