As is so often the case in agriculture, what you lose on the swings you gain on the roundabouts. This seems to be the case in the Orange River wine valley where harvest 2014 has been characterised by a potentially disastrous natural occurrence leading to a set of positives.
The grape-growing region along the banks of the Orange River between Blouputs to the west and Groblershoop to the east was hit by a bout of frost in September of the likes the region has not experienced before. Table grape and raisin farmers suffered huge losses due to the extensive frost caused by night-time temperature plummeting to -8°C.
According to Henning Burger, Manager of Viticulture Services at Orange River Cellars, the frost was the worst the region had seen since records were kept, with many areas that had never seen frost experiencing damage for the first time.
“Table grapes and sultanas suffered as the frost hit between bud break and flowering,” says Burger. “Fortunately for wine production, wine grape cultivars were not that far developed, so when the frost hit us we did not see the extent of the damage incurred by table grape and raisin grape farmers.”
Not that wine grapes in the region got off scot free – with some vines suffering frost damage, Orange River Cellars’ harvest is expected to be 20% lower this year. The harvest began two weeks later than usual this year due to cold, windy conditions in the flowering period, but the fruit is of a high quality and Burger is especially excited about the expected pH levels.
“I expect better pH’s in our fruit due to the cool temperatures experienced between berry-set and veraison when most of your malolactic and tartaric acids are formed,” says Burger. “This extended cool period also gave the plant more time for the production of acidity.”
Burger says that the smaller harvest with fewer bunches will allow the plant to inject more nutrients into the bunches which is conducive to grapes of better quality.
“We just have to hold thumbs that the heat-waves stay away as heat breaks down acids when sugar conversion sets in,” he says. “But at this stage I am predicting wine grapes with naturally high acidity and better pH levels than last year.”
Burger says that temperatures of above 38°C leads to the vine shutting down as a defence mechanism which means that photosynthesis cannot take place.
“But this is the nature of grape farming – you can’t predict nature, or tell it what to do!”
Asked on the challenges of farming in the Northern Cape, Burger says each year he is seeing a greater variance between day and night temperatures.
“One of our farmers’ greatest challenges is to get a newly-planted vine through its first year,” he says. “The past winter and spring saw temperatures going from an average of -2°C at night to 25°C at daytime and this variance puts a lot of pressure on the young vine, often causing it literally crack open.