http://www.engineeringnews.co.za
  SEARCH
Login
R/€ = 14.20Change: 0.11
R/$ = 11.08Change: 0.00
Au 1216.40 $/ozChange: -0.63
Pt 1339.00 $/ozChange: 4.00
 
 
Note: Search is limited to the most recent 250 articles. Set date range to access earlier articles.
Where? With... When?








Start
 
End
 
 
And must exclude these words...
Close Main Search
Close Main Login
My Profile News Alerts Newsletters Logout Close Main Profile
 
Agriculture   Automotive   Chemicals   Competition Policy   Construction   Defence   Economy   Electricity   Energy   Environment   ICT   Metals   Mining   Science and Technology   Services   Trade   Transport & Logistics   Water  
What's On Press Office Tenders Suppliers Directory Research Jobs Announcements Contact Us
 
 
 
RSS Feed
Article   Comments   Other News   Research   Magazine  
 
 
Nov 11, 2011

Portable pressure chambers successful in measuring vine water status

Back
Durbanville|Paarl|Philadelphia|Stellenbosch|Environment|Resources|Water|France|Spain|Too Much Water Stress|Water Stress|Cape Winelands|Water|Measuring Technology
|Environment|Resources|Water||||Water|
durbanville|paarl|philadelphia|stellenbosch|environment|resources|water-company|france|spain|too-much-water-stress|water-stress|cape-winelands|water|measuring-technology-technology
© Reuse this

Dry and windy conditions prior to the 2011 wine grape harvest are proving the merits of wine and spirits pro- ducer Distell’s recent investment in technology to more accurately measure vine water status, reports Distell senior specialist viticulturist Drikus Heyns.

He explains that the measuring technology comprises small portable pressure chambers, or pressure bombs, which gauge the leaf water potential in the vines as a basis for determining optimal irrigation strategies.

The technology was initially developed for research purposes, but it is now used in southern France, Spain and, to a limited extent, elsewhere.
Distell is piloting the technology not only to further enhance grape quality but, also to employ scarce water resources more strategically.

Heyns says although it is important to observe as many variables as possible in the vine’s environment, the most sensitive indicator of stress is the vine itself.

“Until now, we have had to rely mostly on soil water measurements to assess water stress in the vines.

However, the portable pressure chambers we are using in a range of vineyards across the Cape Winelands enable our viticulturists to measure water stress in the vines and to refine irrigation schedules more accurately than was possible in the past,” he adds.

Further, Heyns explains that vines actually benefit from some water deficit as too much water has a negative effect on grape flavour.

To gauge exactly how much water stress is enough is critical to the health of the vines and to the quality of the grapes they produce.

“When there is too much water stress, the stomatae, or pores of the leaves, close, inhibiting the daytime intake of carbon dioxide, slowing down photosynthesis and limiting growth and the production of the grapes,” he says.

Distell is, at this stage, focusing exclusively on testing the technology at red wine vineyards in the Durbanville, Philadelphia, Paarl and Stellenbosch areas in the Western Cape. Heyns and his team visit the vineyards weekly, testing the same vines each time to assess vine health and water needs.

In each instance, leaves are cut and bagged to limit evapotranspiration. The leaves are also covered with an aluminium sheet, which prevents light from opening the stomatae.
The petiole of the vine leaf, which is the stalk attaching the leaf to its stem, is cut and the leaf is quickly placed in the chamber with the cut end of the petiole protruding from the chamber. As the pressure in the chamber equals the pressure or tension in the leaf, the sap is forced out of the cut petiole surface.

A pressure gauge indicates the level of stress experienced by the vine. The degree of stress indicated by the vine is called stem water potential. The pressure reading enables the user to determine the irrigation required.

Allowing for the rooting depth of the vines, soil texture, soil moisture content and vine canopy size, as well as the type of trellising and row spacing, vine water requirements are determined by the extent of evapotranspiration that occurs in the vine and how far the vine is in the ripening of its grapes.

In addition, each wine grape varietal has its own particular water demands.

“The pressure chambers place us in a far better position to manage the health of the vines and ensure optimal-quality fruit to the cellars,” says Heyns.

Edited by: Chanel de Bruyn
© Reuse this Comment Guidelines (150 word limit)
 
 
 
 
 
 
 
 
Other Equipment News
IMPROVING SAFETY Strip curtains can assist with safety, health, environment and quality compliance in industrial applications
Modderfontein-based Apex Strip Curtains & Doors has announced that all its products earmarked for use in the food and beverage industry are now compliant with the latest international food safety system.
FARMING KNOWLEDGE Knowledge and information flows improve farming, land use diversification and more robust agricultural value chains
The World Economic Forum New Vision for Agriculture initiative is helping to develop support for small-hold farmers and larger farmers along existing infrastructure corridors in Africa to stimulate efficient agricultural value chains to support growth in local...
Specialist vibrating equipment provider Joest added US-based particle separation and size reduction solutions company Sweco’s full range of equipment to its product range in June, says Joest MD Kim Schoepflin. The full Sweco range comprises Gyramax gyratory sifters,...
More
 
 
Latest News
President Jacob Zuma would next month officially launch the Dube Tradeport, in Durban, as an industrial development zone (IDZ), the Department of Trade and Industry (DTI) announced on Friday. At the launch event, which was scheduled to take place on October 7, the...
JSE-listed York Timber Holdings on Friday said it expected its operating profit for the year ended June 30 to be between 25% and 30% lower than that of the prior year. As a result of the lower operating profit, combined with a 1% increase in the company’s biological...
Engineering solutions provider ELB Group has reported an 18% increase in turnover for the year, boosting overall income, from R1.9-billion in 2013, to R2.3-billion for the 12 months ended June 30. Describing this as “a satisfactory result, given the current difficult...
More
 
 
Recent Research Reports
Road and Rail 2014: A review of South Africa's road and rail infrastructure (PDF report)
Creamer Media’s Road and Rail 2014 report examines South Africa’s road and rail transport system, with particular focus on the size and state of the country’s road and rail network, the funding and maintenance of these respective networks, and the push to move road...
Real Economy Year Book 2014 (PDF Report)
This edition drills down into the performance and outlook for a variety of sectors, including automotive, construction, electricity, transport, steel, water, coal, gold, iron-ore and platinum.
Real Economy Insight: Automotive 2014 (PDF Report)
This four-page brief covers key developments in the automotive industry over the past 12 months, including an overview of South Africa’s automotive market, trade figures, production and the policies influencing the sector.
Real Economy Insight: Construction 2014 (PDF Report)
This five-page brief covers key developments in the construction industry over the past 12 months. It provides an overview of the sector and includes details of employment in the sector, infrastructure and municipal spending, as well as insight into companies’...
Real Economy Insight: Electricity 2014 (PDF Report)
This five-page brief covers key developments in the electricity industry over the past 12 months, including details of State-owned power utility Eskom’s generation activities, funding and tariffs, independent power producers and prospects for the sector.
Real Economy Insight: Road and Rail 2014 (PDF Report)
This six-page brief covers key developments in the road and rail industries over the past 12 months, including details of South Africa’s road and rail network and prospects for both sectors.
 
 
 
 
 
This Week's Magazine
MANUFACTURING CAPABILITY Reliable Transformers designs and manufactures dry-type and oil-filled power and distribution transformers up to 3.5 MVA
While Ekurhuleni-based transformer manufacturer Reliable Transformers currently designs, manufactures and tests its products according to the SANS 780 specifications for distribution transformers and other applicable transformer specifications, it is working towards...
GHAREEB SAAD Kaspersky Lab products contain strong heuristics engines that monitor suspicious file execution to detect attacks
Global endpoint security solutions company Kaspersky Lab has introduced new measures to prevent cyber criminals from accessing sensitive data, alongside its malware-signature and heuristic device analysis detection methods. Threats to mobile devices have increased...
MICHAEL FLETCHER Real-time information available to government when citizens use publicly funded Wi-Fi networks will enable it to communicate with citizens and provide services
To ensure uptake and a positive impact, Wireless Fidelity (Wi-Fi) networks in cities must be provided at schools, community centres and commercial centres to enable citizens and government to access information that will improve access to and delivery of services....
Eco-estate Monaghan Farm, located near Lanseria airport, north-west of Johannesburg, has taken a new approach to modern living and sustainability with its 517 ha development, dedicated to farm living.
Forklift and lift-truck distributor Goscor Lift Hi-Reach launched the Genie SX-180, the tallest self-propelled super boom in Africa, in Johannesburg last month. “As the official distributor of the well-known Genie range of equipment in Southern Africa, we are pleased...
 
 
 
 
 
 
 
 
 
Alert Close
Embed Code Close
content
Research Reports Close
Research Reports are a product of the
Research Channel Africa. Reports can be bought individually or you can gain full access to all reports as part of a Research Channel Africa subscription.
Find Out More Buy Report
 
 
Close
Engineering News
Completely Re-Engineered
Experience it now. Click here
*website to launch in a few weeks