Summer heat good for grape quality
Marlborough vineyard owners are happy that warmer conditions experienced in recent weeks point towards quality grapes for the 2015 vintage.
The hotter weather has helped growth following on from cooler patches last year that slowed vine and grape development.
The owners are now trimming their vines to make the most of the developing grapes.
Jane Hunter, owner of Hunters Wine, was reluctant to make predictions this far out from the 2015 harvest, which would take place around late March, early April. But she was encouraged by the warmer conditions for her Rapaura Road, Wairau Valley operation outside Blenheim.
Operators of Giesen Wines are also happy with the weather.
To help with the 2015 harvest the winery has invested in new equipment, including spending around $250,000 on an Italian-made "crawler" and associated equipment, to help maintain and replenish the soil in its vineyards, allowing for healthier vines and, high quality fruit.
The Geier machine would perform a multitude of tasks in its organic vineyards including under vine weeding, crop spraying, and trimming, viticulture manager Mike Poff said. The Geier tractor unit alone was $130,000 to $150,000.
The crawler replaced the hefty 2.5 tonne tractor Giesen previously used at the organic Clayvin and Ridge vineyards toturn out pinot noir, syrah and chardonnay wines.
Some of the wine from the specialist vineyards retailed for $50-$70 a bottle and was also exported, so the investment was worth it, Poff said. Another couple of Geier units would be imported in the next year or two.
The crawler, which weighs just over a tonne, and with an overall width of 1.1 metres, has less downward pressure than a human footprint, Poff said. "It is the start of a minimal compaction approach to the company's high-density viticulture."
These Giesen Marlborough vineyards had up to 5500 vines per hectare, more than double the typical planting of 1850 to 2000 vines a hectare. "The rows in these vineyards are only 1.5m wide and the bulkier tractors run right beside the grape vines which can damage the plant's roots. The surface area of the crawler's tracks means a significantly better displacement of weight," Poff said.
Poff says vineyards such as Clayvin and Ridge Block are higher density, with a lower yield of high quality fruit.
"These sorts of vineyards usually produce a bottle of wine per vine. High density means that the vine is putting all its energy into a much more focused crop. The vines are competing against each other, which decreases the vigour of the vine. This competition means that there's less fruit and the vine is smaller with a more concentrated style of fruit."
Following cooler weather at the start of the season, recent higher temperatures had seen a "a huge increase in growth". The grape crop was not as big as in the last couple of years, "but the quality will be great", Poff said.
Hunter said she did not like to predict sauvignon blanc vintages particularly as the 2015 harvest was still a long way out. There might be a lighter crop than anticipated, but signs were promising. "We had the cold weather up until just before Christmas . . . it was not overly concerning because I always think the sauvignon blanc ripens better if it's a bit cooler . . . Now of course we're into quite a hot period and so everything is flourishing, and the grapes are really (good), the timing has caught up . . . I guess now we're keeping an eye on water levels."
New Zealand Winegrowers chief executive Philip Gregan said it was too early to say how the 2015 harvest would pan out. "[But] the warm weather at the moment is exactly what the grapes need at this time of the year. We are still 10 weeks away from harvest, pretty close to that."
- The Dominion Post