GEM was also a high-yielding variety that could be planted at a higher density than Hass and was easier for growers to manage. The variety, which had a tear-drop shape, was well-accepted in international markets. And it matured a little later in the season, meaning the fruit would help fill the post-Christmas/New Year gap in the market.
Seeka growers and marketing general manager Annmarie Lee said GEM would give growers a competitive advantage in the marketplace.
"The Australian market is usually very strong in January and February, and this will allow us to spread supply more effectively and maximise returns for our growers."
Seeka chief technical officer Dr Jonathan Dixon first became aware of GEM 16 years ago when he was working for the Avocado Industry Council, and he saw the variety growing in California while working for the California Avocado Commission.
GEM was discovered in the 1980s, and the cultivar acquired by Seeka came out of the University of California Riverside avocado breeding programme. Seeka acquired the New Zealand rights in 2014 from the master licence holder, Westfalia.
"Our focus over the past couple of years has been to get mother trees established and build those numbers up so we have a good supply of budwood for grafting," Dr Dixon said.
Seeka had licensed two nurseries, Lynwood Nursery in Whangarei and Riversun Nursery in Gisborne, who were building up the stock to supply growers.
Further planting of source trees by Seeka began in September. By early next year 90 GEM trees would be in the ground or top-worked on Seeka-leased orchards, with the first major planting of between 6000 and 9000 trees going into the ground in spring 2017, and a further 6000 and 9000 trees in 2018.
The first commercial quantities are expected in 2019-2020, with volumes increasing from then.
New Zealand Avocado chief executive Jen Scoular said it was a good thing that a new variety was being introduced to the industry.
"It isn't something we could take on as an industry body. Seeka have taken it up," she said.
The variety's attributes of more even production year-on-year were something the industry was looking for, said Ms Scoular.
The main plantings of GEM were also likely to coincide with greater knowledge on how to mitigate the big swings in volumes of the Hass variety.
GEM Avocado key characteristics:
* Less prone to alternate bearing. GEM trees have an alternate bearing index of 0.23, about half the 0.43 for Hass trees.
* Higher yielding. The trees average more than 20 tonnes per hectare in South Africa, and are yielding 10 to 15 per cent greater than Hass in Chile.
* Higher density. The trees are more compact. Seeka is recommending 300 to 400 trees per hectare, with 3m or 4m spacing along a row and 6m spacing between rows. By contrast, Hass typically is planted out at about 184 trees per hectare.
* Later maturing. The GEM variety is expected to mature at least a month later than Hass.
* GEM. The name comes from the initials of the original variety breeder Gray E Martin.
