Growing Futures

Predicting grape production

Predicting grape production

Early knowledge of grapevine production allows growers to manage their vines for optimal harvest

The New Zealand wine industry is recognised for its high quality products. Producing only 1% of the world’s grape harvest, New Zealand is ranked as the tenth largest exporter of wine by value and exports are valued at $1.2 billion each year.

Meeting market demand, while delivering a consistent high quality product, is vital in preserving the position of New Zealand wine in the global marketplace. Reduced export volumes can result in loss of shelf space in retail stores and reduces visibility with consumers, while increased supply can reduce prices and grower returns. Estimating the volume of wine for sale on an annual basis can allow the industry to fine-tune its production and marketing efforts to maximise profitability.

Managing the yield

Grape production can vary by 50% year on year, making it difficult to estimate wine production. Research has demonstrated that potential grape production can be estimated based on meteorological data 15 months before harvest. This information is now used by Sauvignon blanc growers to manage production.

By estimating production early, vines can be managed through pruning and mechanical thinning, a more cost-effective process than traditional hand thinning at later developmental stages. It is estimated that, in high yield years, the wine industry can save upwards of $5 million by managing crop harvest early.

Maintaining harvest volumes

The New Zealand wine industry has estimated that harvests between 310,000 and 340,000 tonnes match the industry’s current market position and supports growth of exports based on delivering premium products. Meteorological activity in 2012 suggested that the 2013 harvest would be significantly lower than the long term average, and growers managed their vines accordingly during the winter-pruning season. The 2013 harvest subsequently produced 345,000 tonnes of grapes, about 30% higher than the previous year and slightly above the long-term average.

Development of the grapevine yield calculator was funded by Lincoln University, New Zealand Winegrowers and the Sustainable Farming Fund with support from vineyard and wine companies.

Created: September 2013

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