Two new computer programs designed to help Hawke's Bay grape-growers interpret weather data could transform how they
manage their vineyards, improve the quality of their crop and reduce environmental damage.
The programs are the result of a three-year research project by 15 growers and wine companies.
"The project aimed to improve growing methods by monitoring the weather better - which dictates use of sprays - and
managing pests more intelligently," project manager Campbell Agnew says.
Technology New Zealand - part of the Foundation for Research, Science and Technology - helped to fund the research.
"The new programs were developed because winegrowers wanted data about how weather helped cause disease," Mr Agnew says.
"We looked overseas for the data and fed it all into the computer. The programs were designed around that data."
The system involves national or local forecasters supplying weather information to growers, which is entered into their
computer. The programs contain objective measures that help growers decide when to spray against pests.
"The usual way of doing things has been to spray regularly - say, once a fortnight - whether you need to or not," Mr
Agnew says. "Sometimes up to 14 times a season. Now we can manage pests more intelligently. We can evaluate the use of
spraying and target pests better.
"For example, some of the sprays control the natural predators rather than the pest, which is not what we want. A new
wasp that targets the leafroller grub lays eggs in the grub and as the eggs hatch they eat the grub. We want to
encourage that.
"And ladybirds are a natural predator of the mealy bug, which lives on vines then moves to the bunch and excretes a
honey dew on it. We want to protect the ladybirds, not kill them."
Mr Agnew says the project will help growers achieve better-quality fruit, reduce spray costs and the impact on the
environment, and let natural predators do their work.
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