Kiwifruit Good News
January 17, 2011
The kiwifruit disease, PSA, is never far from kiwifruit growers’ minds but Katikati orchardist Peter Hope believes he already had the best insurance in place before the threat came to light.
For the last five years Mr Hope and wife Barbara, who manage two kiwifruit orchards as well as their own, have used the New Zealand-made biological spray Agrizest to boost vine health.
Healthy and vigorous vines have paid dividends in greater productivity, Mr Hope says.
On one established, 2ha orchard growing gold kiwifruit he expects production to top 20,000 trays per hectare this year, a harvest that will be at the high end of the industry scale.
A green kiwifruit orchard that’s just producing its fourth crop is carrying an estimated 15,000 trays a hectare.
“You can’t get that sort of production unless they are healthy,” he says. “Once you’ve got healthy plants all the other things start to happen for you.”
Agrizest, a certified organic agricultural compound, strengthens a plant’s defence system and enhances its ability to repair damaged cells. It was just what some of Mr Hope’s vines needed five years ago when a failed experiment with trunk girdling left the plants weak and their leaves small and yellowing.
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It was late October when the leaves should have been big, glossy and pouring goodness into the plant that Mr Hope had a chance conversation with Te Puna grower and horticultural consultant Mike Muller about the ailing vines. Mr Muller suggested they might benefit from Agrizest.
“We put it on and within five days the leaves turned from yellow to a nice deep, dark green and the orchard hasn’t looked back since,” Mr Hope says.
The benefits from Agrizest continued in the following and subsequent years. “We had big leaves right at the beginning of the season and it was especially noticeable in the second and third years. The orchard matured really quickly.”
Mr Hope applies Agrizest four times a season, twice before and after flowering, as recommended by Agrizest inventor and marketer, horticultural scientist Nathan Balasingham.
The regime is “well and truly” a good investment at $300 per hectare, Mr Hope says. “We may cut out other things but not Agrizest, especially with PSA around. The healthier your vines are the less likely you are to pick up disease.”
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Agrizest works by suppressing bacterial diseases, of which PSA is one, by switching on the plant’s own defence mechanism contained in its essential oils or phenylpropanoids.
The benefits of Agrizest are not just confined to kiwifruit, says Mr Hope who has used it to good effect on avocado trees, young fruit trees, the family vegetable garden and even on Mrs Hope’s roses.
“It had a big effect on the roses. It just makes everything start to hum along. Everything just looks healthy and has good vigor.”
Mr Balasingham, a former DSIR scientist with a Master of Horticultural Science with first class honours in biochemistry and more than 30 years in research and development, said Agrizest enhances the plant’s ability to resist pests and reduce disease damage.
Agrizest is one weapon in growers’ armoury against disease, Mr Balasingham says.
“Agrizest will give growers a payback whether they have PSA in their crop or not. The improved fruit quality and quantity will deliver improved returns. All our independent trials show an increase of more than $5000 per hectare.”
Agrizest can be used in conventional and organic orchards (if approved by Biogro).