News VineFacts
THE
2017/18 SEASON
Photo Tiki Wines, Marlborough. SUPPLIED BY NZW.
If there was one story that kept occurring after vintage 2018, it was the impact of weather on all regions. As vintage figures show, many regions had a major increase in yields this year, with Central Otago seeing a jump of 36 percent when compared with last year. In contrast Marlborough saw a modest increase of just 4 percent. VINEFACTS WHICH monitors weather and phenology of six regions throughout the growing season, (September – April) shows best how much weather played a part in the final vintage figures. Firstly temperature. Every one of the six regions saw an increase in temperatures over the 2017/18 season, when compared with the long-term average, (figure 1). Yes it was a hot season – as the graph above shows. Marlborough and Central Otago had their warmest summer in at least 28 years. Wairarapa had its warmest season in at least 15 years. For Gisborne, Hawke’s Bay and Waipara – it was their second hottest summer in 28 years. Those temperatures added to the increase in growing degree days, particularly early on in the season, (figure 2). The most notable feature of the total GDD graph is that from late November 2017 through until early-February 2018 Central Otago was tracking with almost the same total GDDs as Gisborne. In a typical season Central Otago normally records the least total GDDs throughout the season and the line is the lowest on the graph. However, in mid-February 2018 the weather pattern in Central Otago changed markedly with much cooler temperatures and the slope of the GDD line was much flatter from that point onwards. When it came to rainfall, Hawke’s Bay and Gisborne were below the long-term average, but elsewhere it was a different story. The effects of two cyclonic events in February impacted especially on Marlborough and Waipara, (figure 3). As the graphs show – 2017/18 was a season that won’t be forgotten in a hurry. Warm, wet and a number of climatic events that impacted on yields throughout. For more information on VineFacts and how you can receive the information this coming season, visit vinefacts@ nzwine.com
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NZ WINEGROWER AUGUST/SEPTEMBER 2018
Figure 1
Figure 2
Figure 3