South Africa’s wine grape crop for this year increased slightly, albeit at lower levels than expected, owing to significant fluctuations in weather conditions, besides other factors.
The 2011 wine grape harvesting and growing seasons were subjected to harsh climate fluctuations, such as drought and heat, reports viticulture, oenology, soil science, agroeconomy and general management consultation services organisation VinPro.
The organisation notes that a larger crop was initially expected, but cold and windy conditions during the flowering season contributed to a systematic reduction in the crop.
Nevertheless, nonprofit industry body South African Wine Industry Information and Systems (Sawis) in August indicated that the 2011 wine grape crop had grown by 3.1% year-on-year to about 1.3-million tons, compared with about 1.23-million tons in 2010.
The 2010 crop harvest declined by 8.6% on 2009’s crop, which was estimated to be just over 1.3-million tons.
With the exception of the Orange River, Breedekloof and Worcester districts, all cultivation districts had bigger crops this year.
At the start of the 2011 growing season, regular showers resulted in a prevalence of fungus, necessitating the implementation of preventive spraying programmes.
Further, cold and inclement weather conditions resulted in an uneven and weak set of cultivars and grapevines that are prone to later bud burst; this impacted considerably on the crop size, reports VinPro.
Hardly any rain was recorded from mid-November 2010 and the unrelenting heat from January onwards made it tricky for producers to implement suitable irrigation.
Further, during the ripening period, dryland vines suffered as a result of a lack of supplementary rain, while persistent thunderstorms and high humidity led to problematic rot control challenges in certain regions.
In addition, VinPro reports that, during the warm, dry ripening period, several cultivars ripened simultaneously, thereby placing severe pressure on cellar capacity at times.
Orange River Crop Decline
The Orange River district’s crop was particularly hard-hit, with estimates showing a 23% year-on-year decline in the district’s crop to 128 671 t in 2011.
The decline is a result of extensive flooding and rot. Initial estimates indi- cated that the 2011 crop would be smaller than 2010’s because all wine cultivars, including Sultana and Merbein, had smaller crops.
Following the floods, a survey under- taken by wine producer Orange River Wine Cellars, indicated that 366 ha of wine grapes was destroyed, while a further 640 ha of wine grapes suffered indirect flood damage.
Carbon footprint research project Confronting Climate Change project manager for the Fruit & Wine Industry Initiative Shelly Fuller says wine producers are concerned about the unusual seasonal weather changes.
She says seasonal fluctuations have become more prominent in recent years, and wine farmers have had to adapt their production operations to remain profit- able and produce high-quality wine.
“The seasonal fluctuations affect every aspect of their production, from increased pest and disease problems to early or late flowering and budding. Harvest periods, as well as the quality and quantity of wine, are impacted,” she adds.
Fuller highlights that wine farmers are looking at ways to adapt their busi- nesses to keep up with changing weather conditions. “Depending on the growing regions, some farmers are changing their grape varieties to more drought-resistant and heat-tolerant cultivars,” she says.
In addition, others have bought farms in coolers regions, such as the Grabouw valley, in the Western Cape, to grow their white wine varieties there. Vineyards are also moving farther up mountain slopes to reach cooler microclimates.
The major issues for the farmers are the longer, warmer summers and drier winters, which result in less water for irrigation in summer.
Further, she notes that the problem of fluctuating weather patterns and climate change will not be resolved any time soon.
Confronting Climate Change’s three-year carbon footprint research project, which started in 2008, aims at enabling South African growers and service pro- viders to determine their carbon footprint and identify carbon hotspots with the objective of finding creative measures to reduce carbon emissions.