Planning eases heatwave burden for Mount Horrocks

Name: Stephanie Toole

The March heatwave that troubled many South Australian growers in the midst of the 2008 harvest was a 'blessing' according to Stephanie Toole, owner and winemaker of Mount Horrocks Wines, in Auburn, Clare Valley. Toole said her forward planning eased the pressure of the harvest that accelerated with the mid-vintage heatwave.

Most vineyards were scrambling to harvest their fruit before the heat took hold, and wineries were pressured to process the fruit quickly - forcing some producers to look outside their region for crushing services. Not so for Toole, who was revelling in the heat for her Cordon Cut Riesling vineyard. The cane cut fruit, reliant on dehydration and shrivelling on the vine, was cut just before the heatwave and resulted in concentration occurring much quicker than in normal years.

'Prior to every vintage, bunch weights and bunch numbers are recorded to determine how much fruit we are likely to pick from each vineyard. This enables us to work out exactly how much tank space is required, given normal picking times, when the fruit has been processed and then put to barrel to make space for the next fruit from the vineyard as it ripens,' Toole said.

'We have a high tank/wine ratio at the winery and while things got a little tight, we didn't run out of tank or winery space. At no time did we have to stop picking because the winery was full. Having enough space meant avoiding overload at the peak of vintage.'

Toole said after the drought year of 2006-07 it was important to put in place a comprehensive vineyard plan. This involved reducing bud numbers with initial pruning and following up with shoot thinning and crop thinning as the season progressed to keep yields down.

'It was obvious that the lack of water and insufficient winter rains was again going to be a problem for the 2007-08 season, so maintaining a healthy canopy and low yields meant the fruit ripened fully without any stress. This resulted in the majority of my fruit being picked before the heatwave hit.

'Unfortunately, water is severely restricted and irrigation is limited. It is important to make sure the vines do not stress during the important times of the season like flowering, rather than later in the season,' Toole said.

Although the 2007-08 vintage went according to plan for Mount Horrocks, Toole and her team are reviewing their management plans for 2009. This has involved spreading straw under-vine and organic mulch across rows to aid moisture retention and weed control. Bud numbers and lengths of arms have also been revised to allow for what Toole believes is most likely to be a 'water restricted year'.

Despite the challenging 2008 vintage, Toole was pleased with the end result.

'Up until the heatwave hit, the year had been reasonably cool. Low yields and healthy canopy cover in the vineyard meant that most of my fruit was picked before the heatwave. What fruit was left in the vineyard was well-protected by a healthy canopy. I hand picked everything, so adjustments had to be made during the heatwave by limiting the picking times from seven in the morning to midday and dealing with the fruit quickly, as soon as it arrived into the winery, to minimise oxidation. Of course, in the case of the Cordon Cut Riesling fruit, the conditions were perfect!'

Mount Horrocks is involved with Trees for Life, offsetting all its carbon emissions by counting its yearly carbon emissions (car, air travel, electricity/gas) and trading them off by planting an equivalent number of trees. Toole believes that climate change is a serious problem that affects everyone and Mount Horrocks' involvement with Trees for Life is a way for the winery to help combat salinity and restore biodiversity in its vineyard.

This article first appeared in the July/August 2008 issue of Australian Viticulture. To get your copy of the issue or to subscribe to the magazine contact Winetitles on +61 8 8292 0888 or email [email protected]

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