New Zealanders adopt dwarfing rootstocks
Apple growers hope to revitalize their industry with new varieties and intensive plantings.
Good times led to complacency, says Craig Hornblow.
In the last few years, New Zealand apple growers have been planting trees on the dwarfing Malling 9 rootstock in an effort to improve the efficiency of their orchards.
Traditionally, New Zealand orchardists have used the larger Malling 106 or M.793 rootstocks, which are resistant to woolly apple aphid. A typical Braeburn planting in the past had trees spaced 3 meters (10 feet) apart with 5 meters (16-1/2 feet) between rows.
Craig Hornblow, a consultant with AgFirst in Nelson, New Zealand, said that about 90 percent of recent plantings in the Nelson area have been on the M.9 rootstock and the rest on new rootstocks from New York's fireblight-resistant Cornell-Geneva series.
"We were very slow picking up on the M.9 trend," Hornblow said. "We didn't start planting M.9 on a large scale until six years ago.
"The enemy of great is good," he added. "We had a good time in the 1990s with Royal Gala and Braeburn. We could not do anything wrong with M.l06. There was no real reason to strive and get more efficient and get better."
But times have changed. Although yields are high in New Zealand's conditions, growers are having difficulty growing large fruit on old Royal Gala trees and are struggling to get good returns on Braeburn from Europe. "That really was our catalyst to change," he said.
Growers learned how orchardists in other parts of the world, such as the South Tyrol area of northern Italy, revitalized their industries with more intensive plantings.
Apple production in the Nelson area has declined over the past few years by about 20 percent from a peak of 6 million boxes annually, but it is still the South Island's major apple-producing region, producing about 30 percent of the national crop. About 65 percent of New Zealand's 17-million-box crop is produced in the Hawkes Bay area on the North Island.
The Nelson area, situated at 42°S on the north coast of the South Island, has a temperate climate. Summer temperatures are generally between 18 and 20°C (64 and 68ºF) and rarely exceed 30°C (86ºF). Though it boasts that it is the sunniest place in New Zealand, it receives almost 1,000 millimeters (40 inches) of rain annually. It has heavy soils with good water-holding capacity.
Hornblow said the Nelson area's first commercial orchards were planted at Motueka in the late nineteenth century, and commercial apple production began in about 1910 when syndicates were formed to buy large tracts of land. These tracts were divided up into small blocks that were offered to people who wanted to start growing apples to export to the United Kingdom, "the Mother Country," as Tasmanian orchardists were already doing.
By 1937, the region was producing a million cartons annually. In the 1980s, tobacco was the main crop around Motueka, but a number of farmers switched to kiwi or apples.
Gala and Braeburn make up more than 75 percent of the district's production, but are declining in importance, along with Cox. Some Fuji is being grown, though growers struggle to get good finish.
Although the district grows the majority of New Zealand's Jazz, that's only about 333,000 boxes so far, Hornblow said. "Even though there's a lot of talk, it's only a little profit to the region."
There have been recent plantings of Delbush (marketed as Tentation), which is a managed variety from France. "What we're looking at is an integrated approach to new varieties, with someone to take it to the consumer," Hornblow added.