Theuns Rabie won the 2009 Hex River Valley Table Grape Block competition with 1,3ha Crimson Seedless, which yielded 5 700 cartons of export grapes. No stranger to accolades, he believes a winning block is established within the first year or never. Wouter Kriel visited the farm Buffelsrug and heard about Theuns’s particular brand of grape TLC.
THEUNS RABIE OWNS 34HA TABLE grapes and 10ha wine grapes on his two farms, Buffelsrug and Môreson, in the upper Hex River Valley, and rents another 16ha of table and wine grapes. He recently won the 2009 Hex River Valley Table Grape Block competition for the fourth time since 1993, with a 1,3ha block of Crimson Seedless on Buffelsrug.
The 2009 winning block was established in 2002 on a factory-style trellis, with vine spacing of 3m between and 1,8m in the rows. During the 2008 season it yielded 5 700 cartons of export grapes and Theuns expects 6 000 cartons in 2009.
Tending the winning vines
“We pruned the vines into eight long bearers with 10 to 12 buds per shoot and with two short bearers with two buds on the back,” Theuns explains.
“All bunches on weak shoots were removed. We kept one bunch per shoot, but if bunches were well-spaced and on a strong shoot, we kept two. On average, that gave us 25 bunches per vine.”
He sprayed a thinning spray on 50% of the set. The first enlargement spray, consisting of Gibb, CPPU and Kelpak was applied when berries were between 8mm and 10mm in diameter. “On 5% véraison (change of colour of the grape berries), we sprayed Ethapon for colour, followed by a KDL spray, which was followed with another Ethapon spray seven days after the first,” he explains.
Soil and irrigation
“My soil is a mixture of heavy clay and loam – the old people used to say it contains a fine coffee-bean stone grit,” says Theuns. A rock bed 1m to 1,5m deep enhances drainage, while the heavy topsoil retains moisture for long periods. This has various advantages if managed correctly. “Unlike modern pulse irrigation, which provides frequent short applications of water, we irrigate once a week for deep penetration,” Theuns says. “In early summer we’ll irrigate 21mm per week and as the season heats up we’ll increase it to 56mm per week.”
Theuns believes in microjet irrigation, but admits he’s experimenting with drip irrigation because of its water-efficiency. Seedless cultivars are prone to berry burst from too much water too quickly, but Theuns says this doesn’t happen when there’s rain during harvest season, because water uptake is delayed by the heavy soil.
Soil moisture is checked once a week, using the Diviner 2000 system. “I use the measurements as a guideline, but make my final irrigation decisions based on vine growth, berry size and various other factors.”
Theuns believes in resting soil before establishing new vines. When an old block is removed, the land is ripped in one direction to between 1m and 1,5m deep, depending on the soil. Triticale is sown for one year, and the land is cross-ripped before new vines are established.
Whether or not to establish vines on ridges is an important decision, says Theuns. “Vines in shallow soil will benefit with ridges, as roots can penetrate deeper. Ridges tend to be hotter than a flat land, so you can expect ridged grapes to ripen earlier.”
He established vines on a gable system, splitting the vines. “Many farmers prefer flat-roofed structures for seedless varieties such as Crimson, but I prefer the slanted factory structure as I believe the construction is stronger. The leaf surface per hectare is the same, but there’s still a gap for air and sun penetration,” he says. If a new block doesn’t grow uniformly, Theuns cuts it back, preferring to sacrifice one year’s yield than have to deal with an uneven production unit later on.
Ongoing maintenance
Theuns applies 1 000kg/ha of Cormorant Gee, a mixture of guano and chicken manure, after each harvest. Triticale is sown in the rows, receiving a 100kg LAN application at five-leaf stage. At blossoming another 300kg/ha Cormorant Gee is applied. All fertiliser is applied by hand, to compensate for soil variation. Spots with weak growth will receive additional LAN. When berries reach pea size, 100kg/ha calcium sulphate is applied.
“We do all vine work as quickly as possible after pruning in the winter,” Theuns explains. “This includes suckering, anchoring, tying shoots, removing leaves around bunches, and trimming and eliminating bunches. The vineyards are weeded as much as possible. The balance between foliar growth and light penetration is crucial – too much shade hurts vine fertility, but grapes should also be shaded enough to prevent sunburn.”
Theuns follows a preventative chemical spray programme. “I spray for downy mildew and even in favourable weather conditions. From a shoot length of 20cm, we apply two to three yellow sulphur sprays weekly, and three to four copper sulphur sprays up to a week before harvest. “We do a post-harvest spray against downy mildew and white rust. White louse-infected vines are treated individually.”
Relying on labour
Many farmers were forced to reduce their permanent labour force, due to the labour legislation, and they started using external contractors instead. Theuns, however, persevered and still employs a permanent on-farm labour force of 60 men and women.“Some of these families have been with me for 20 years and their loyalty towards the business shows in their work which is of a very high standard,” Theuns says.
Contact Theuns Rabie on (023) 356 2303. |fw
Combating water problems
The upper Hex River Valley is known for its heavy Karoo soils and former water problems. Farmers here used to depend on winter rain draining from the Matroosberg Mountain, which fed into two open furrow systems and was stored in on-farm dams, before government constructed the Roode-Els and Lakensvlei dams in the lower valley in the 1960s.
The government dams improved water security tremendously, but during dry years farmers from the upper valley didn’t have sufficient water. Recently this problem was addressed by the construction of the Osplaas Dam, which is filled during the evenings from the Roode-Els and Lakensvlei dams. This significantly enhances the upper valley’s water security.
Two pipe systems recently replaced the furrow system of the Matroosberg and Bovenstewater irrigation schemes, improving Theuns’s water allocation from these systems from 20 000m³ to 85 000m³. Four years ago, before these improvements, Theuns was forced to use saline borehole water in a dry spell. “We applied gypsum to counter the salinity, and rehabilitated the soil afterwards with Nemacur to kill all non-beneficial soil microbes. We followed this up with an organic product, Bio-Terra, which stimulated healthy soil organisms to multiply again. We also applied two to three Herbali foliar sprays to help restore plant health.”
Today, thanks to the improvements, Theuns has water for 90ha of grapes. “But I’ll only establish up to 60ha, as from now on I always want a water buffer,” he says. Theuns is also continuing with annual Bio-Terra and Herbali applications.
