http://www.engineeringnews.co.za
  SEARCH
Login
R/€ = 14.17Change: 0.03
R/$ = 11.07Change: 0.01
Au 1238.28 $/ozChange: -4.47
Pt 1258.00 $/ozChange: 3.00
 
 
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 Brewery and Winery News
Rapid and accurate in-line measurement of alcohol is importantin the distilling industry to ensure successful and profitable management of the process. This applies equally to modern and traditional plants, particularly in the current economic climate states liquid...
Economic consultation firm Econometrix completed a study regarding the Control of Marketing of Alcohol Beverages Bill and found contradictory evidence of the results of the country’s proposed alcohol advertising ban. The study was conducted locally and...
South Africa’s wine consumption grew from 6.1% in 2011 to 7.2% in 2012, owing to increased consumption by black South Africans, states CEO of official wine education body in South Africa the Cape Wine Academy and Cape wine master Marilyn Cooper. “Consumption...
More
 
 
Latest News
A former employee of the Manufacturing, Engineering and Related Services Sector Education and Training Authority (Merseta) and his accomplice have each been sentenced to 20 years imprisonment after being found guilty of fraud by the Specialised Commercial Court, in...
The Richards Bay Bulk Terminal, in KwaZulu-Natal, loaded 1.49-million tons of cargo in September, exceeding its monthly target of 1.32-million tons, Transnet Port Terminals (TPT) said on Monday. TPT said the reaching of vessel targets ahead of deadline created...
Judge Dennis Davis
The revenue implications for South Africa of ‘base erosion and profit shifting’ by corporate taxpayers are firmly in the crosshairs of the Davis Tax Committee (DTC) and Judge Dennis Davis hinted on Monday that recommendations were being considered to “detect and...
More
 
 
Recent Research Reports
Defence 2014: A review of South Africa's defence industry (PDF Report)
Creamer Media’s Defence 2014 report examines South Africa’s defence industry, with particular focus on the key participants in the sector, the innovations that have come out of the sector, local and export demand, South Africa’s controversial multibillion-rand...
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.
 
 
 
 
 
This Week's Magazine
The broad-based black economic-empowerment (BBBEE) alignment process in the con-struction sector has begun, dur-ing which the sector codes of the Construction Sector Charter Council (CSCC) will be aligned with the revised Codes of Good Practice (CoGP), which come...
It is second time lucky for Toby Venter. Ten years ago he negotiated to buy the Kyalami racetrack, but “the deal did not materialise”.
Environmental solutions company I-Cat started construction work on its R22-million, 1 949 m2 environmentally sustainable office and warehouse facility, commissioned by I-CAT Environmental Solutions, at a launch event in October. The new sustainable I-CAT campus,...
IAN EVANS AirWatch file synchronisation and sharing system was initially designed for a large airline company
Effective file synchronisation and sharing across an organisation’s structures can provide the basis for robust mobile-device and document management while maintaining proper backup, version control and content distribution. These are the lessons learned by complex...
Hotel group Carlson Rezidor currently holds the largest hotel pipeline in Africa with 30 hotels and 6 300 rooms under development. The hotel group develops and operates Radisson Blu in the upper upscale segment and Park Inn by Radisson in the mid-market segment. With...
 
 
 
 
 
 
 
 
 
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