HortNews
	New Version Of Kiwifruit Variety A Sweet Little Number

TAURANGA 17/12/1999 - A sweet little number, called Actinidia arguta, is being grown at HortResearch's Te Puke plant breeding centre where kiwifruit species are under development.

But the latest variations of actinidia arguta are not yet ready for commercialisation although there are two selections that look likely candidates for development, according to plant breeder Dr Mark McNeilage.

One of these could perhaps add to the three commercial varieties, hayward, early start and zespri gold that already make up New Zealand exports.

Plant material is being bulked up and should be available to orchardists in about 18 months.

About the size of a large cherry and completely hairless, the actinidia arguta species comes in red or green, and has previously been marketed under names such as "kiwigrape".

In the South Island, Kotinga Kiwifruit Partnership, of Golden Bay, started marketing red, pink and green arguta fruit from the species -- rather than the scientifically bred commercial selections --in 1991, at more than double the price of larger, traditional varieties. Initially they were labelled as "cocktail kiwifruit", but in 1995 year the labels were changed to "baby kiwifruit" for the Japanese market.

The arguta plants were introduced into New Zealand in 1955, but commercial interest was aroused only in the 1980s through HortResearch's plant breeding efforts on behalf of the Kiwifruit Marketing Board.

Cross-breeding has since corrected a number of deficiencies, and high-quality selection had been propagated for orchard trials around New Zealand, so that the best cultivars could be recommended for release, with data on the best harvest maturity and storage conditions on each selection, along with advice on vine management.

The fruit's taste varies between selections, with some reminiscent of grape and feijoa flavours.

The Hortresearch breeding programme has sought ways to carry the thin green skin, high sugar content and superb flavour over into new cultivars.

Researchers had also discovered peculiarities such as early bud break, fruit softening on the vine, seasonal variations, different packaging requirements to "standard" kiwifruit, and some factors contributing to low yields despite adequate fruit production.

Crosses with bigger fruiting species such as the ordinary kiwifruit, actinidia deliciosa, have produced hybrids with comparatively large fruit with a green hairless skin, and crosses with actinidia melanandra produces large crops of small but very sweet fruit with very good flavour and, on some vines, red flesh.

The arguta species is hardy, able to resist temperatures below minus 30degC in winter, and capable of growing from Kerikeri to Clyde in New Zealand.

It ripens from late February to early March and some new selections can be cool-stored for at least two months and still have a shelf life of more than a week.

That made them suitable for both export and domestic markets, Dr McNeilage said.

Small quantities are already grown in other countries in Europe, the USA and Canada.

But the selections being cultivated by Hortresearch should provide an edge for New Zealand growers -- especially when they are protected by plant variety rights (PVR).

The species were grown from actinidia crosses first made in the late 1980s and development now was focused on commercial trials in different regions of the country in the search for arguta's perfect growing conditions.