International breakthrough for kiwifruit control
New Zealand research is on the verge of delivering a new biological control agent to keep in check one of the most
troublesome diseases affecting kiwifruit.
The new remedy is being developed as a replacement for the current fungicide which is used but is under increasing
threat internationally of being withdrawn, as the worldwide fruit industry strives to reduce persistent chemicals from
the supply chain.
Without an effective replacement control for the disease, Sclerotinia, kiwifruit growers could face losing up to
one-third of their crop each year. Sclerotinia infects the flower, stopping fruit development, and is the single biggest
disease threat to kiwifruit growers.
The biological control breakthrough is the result of the combined efforts of specialist horticultural products
manufacturer, Gro-Chem NZ Ltd, HortResearch, Amberley Management Services Ltd and government research and development
funding agency, Technology New Zealand that provided $175,000 towards the three year project. Zespri New Zealand is also
supporting the research.
“There is huge potential for the product to change the industry. It’s a major step forward and will have huge impact,”
says Gro-Chem Project Manager, Iain Latter.
“It will maintain New Zealand’s strong market access and reputation as a leader in minimizing hard chemical use,
enabling growers to achieve premium prices on international markets,” he says.
There is also scope to license the new biological control agent (BCA), ‘EPICURE’, to supply overseas growing areas once
chemical registration and commercialisation is completed in New Zealand.
HortResearch identified the new BCA but the chance to develop it commercially could easily have been lost.
“We wouldn’t have taken on this project without the support of Technology New Zealand.
“We’re a rapidly growing New Zealand company but without that assistance this wouldn’t have occurred because the
development of BCAs is a reasonably risky project and our resources are limited. It wasn’t a certainly although we have
had a high success rate with other BCA development,” says Iain Latter.
Test results show EPICURE to be effective, if not more so, as conventional chemical control, and Gro-Chem is now in the
process of registering it for commercial use in New Zealand next season.
The EPICURE is delivered to flowers using conventional spray systems. It was hoped, as part of the project, that a more
efficient method of delivery could be used instead of conventional spraying.
BeeFORCE technology, which involves a mechanism attached to hives that delivers the BCA to bees as they move in an out
of the hive, appears promising. However, testing had to been confined to cages as there is no way to control bees in an
open environment. Any crop touched by bee carriers during the testing phase of the product before registration would
have had to be destroyed.
More work will be done to assess the use of the BeeFORCE equipment once registration is gained. Bees may be more
efficient carriers because they penetrate the crop canopy more effectively, and less product would be required.
Technology New Zealand Investment Manager, Hamish Campbell, said the project stretched the capabilities of Gro-Chem and
involved a high value, high return product.
“New Zealand has more than 11,000 hectares of planted kiwifruit and a successful result will enhance the global
marketing opportunities for growers, with the prospect of improved export returns,” he said.
Kiwifruit is among New Zealand’s top four horticultural exports. Net global sales topped the $911 million mark in the
latest season, with more than 65 million trays being sold into around 65 different countries.