The Soil & Health Association is calling for Sustainable Wine Growing to lift its game, as close to 70% of Marlborough’s grape growing area is currently herbicide sprayed said Soil and Health spokesperson Steffan Browning.
The current practice of complete herbicide burning every second path as well as the under-vine strips, or frequently 100% of the surface area, to assist in frost protection, is making Marlborough’s Wairau Valley, a Herbicide Valley with an estimated 70% of vineyards sprayed with herbicide, he said.
He said many operators say it is ‘just Roundup or glyphosphate’, but Monsanto agreed 10 years ago to discontinue the use of terms such as "biodegradable" and "environmentally friendly" in all advertising of glyphosate-containing products in New York state.
Carcinogens and endocrine disruptors
Some surfactants and glyphosphate break down products, and also Amitrole another widely used herbicide, are known carcinogens or endocrine disruptors, said Mr Browning.
“Denmark has restrictions on glyphosphate to prevent groundwater contamination and local authorities there are being proactive to encourage more sustainable management.”
The economic convenience of harmful herbicides and pesticides is creating areas such as Hawkes Bay and Marlborough as potential health risks.
In Marlborough the main population areas of Blenheim, Renwick and Seddon are surrounded or downwind of the spray zone.
Organic grape growing
Organic options, like green crop cultivation, mulching, compost application and the use of effective micro-organisms, not only reduce frost damage, but also improve soil health and take carbon dioxide out of the air to be stored as soil carbon.
Nicole Masters of biological soil consultants EcoAgriLogic said herbicide use is proven to reduce vine health through protein disruption, and because beneficial soil and plant organisms are killed, there is an increased susceptibility to pest and disease.
“Herbicides also reduce grape storage life, and natural flavours can also be expected to be rounder without their use.”
Wine Growers says S & H figures inflated
"Meanwhile, the Marlborough Express reports that New Zealand Wine Growers chief executive Philip Gregan has defended wine growers use of sprays. Mr Gregan said Soil and Health's figures were "grossly inflated" and that some growers had little option to broad acre spraying as there was a huge amount of money at stake, he said.
Spraying in the Awatere and Wairau is declining sharply and the industry is looking at other options, such as mulching with paper, hay or even mussel shells for frost protection, he said.
Sustainable Wine Growers national coordinator Sally van der Zijpp said any grower using year-round blanket spraying would be excluded from the programme. SWG was trying to get growers to move away from blanket spraying during the frost season and look at other options but some found it a little difficult if they had no other means of frost protection, she said.