Drip on Wine Grapes: Less Water, More Control

Innovate. Adapt. Overcome

Whether driven by drought, research or vineyard experience, the wine grape industry continues to learn the need to continually adjust to not only overcome the challenges thrown at it, but to stay ahead of the game.

“The most important lesson the industry has learned and continues to learn, is that the same results can be achieved with less water,” Briaan says. “We’ve learned this from experts such as Dr Phillip Myburgh and Vink Lategan, but also from near­debilitating droughts.”

The regulated deficit irrigation (RDI) trend in the wine grape industry was one of the driving factors for important irrigation management lessons. “In the late ’90s and early 2000s we started with RDI trials and it became an important concept in the industry,” Briaan says.

The philosophy of RDI is to manage irrigation to place the vine under controlled stress between the berry set and vé raison stages, Leon says. The aim is to limit berry size for a better skin­to­pulp ratio. “This is, of course, under intensive irrigation and the application of the philosophy differs for supplementary irrigation where the first round of irrigation may just be delayed.”

The impact of this concept on our understanding of water management in wine grape production has been massive, Briaan says. “Today, we’re not necessarily practising textbook RDI, but rather the lessons learned from it. A world of controlling when and how water is applied, managing water application at certain phenological stages and doing the job with less water has opened up for the industry.”

The right amount at the right time

The biggest mistake most wine grape producers still make is to use a too high delivery rate for irrigation, Jaco says. “The industry has made important strides when it comes to using narrower spacing and lower dripper flow rates.

This has had a massive impact on our water-use efficiency and results in the vineyard.” Data collection also plays an important role in the final success. "It's important that producers monitor soil moisture to ensure that the root zone is correctly wetted,” Jaco says. “You must also monitor test dripper flow rates to ensure you’re delivering exactly the amount of water you think you are. Use the modern tools available to help you make informed irrigation decisions.”

Leon’s most important advice to producers is to not over­irrigate. “Apply only the exact amount of water the vine needs, and your soil profile can handle. Don’t waste water. According to Leon, one irrigation strategy will help you reach a maximum yield goal, while another will help you reach a grape quality goal. Start with what you want to achieve given your conditions and resources and shape your irrigation strategy accordingly.”

At your service

When wine grape industry experts are asked what they expect from the irrigation industry now and in the future, they agree it has a responsibility to help producers stay ahead of their challenges. “The industry must ensure that we keep up with the latest irrigation technology and methods,” Jaco says. “Producers must be able to rely on the irrigation systems made available to them.”

“We’ve seen a massive development of technology in the irrigation industry,” Briaan says. “These technologies make drip irrigation adaptable to a wider range of circumstances and open up new possibilities in the vineyard.”

The focus should be on innovation, Leon says. “Irrigation companies that continue to innovate will help the wine grape industry to use less water and achieve better results. This will ensure that the industry remains sustainable.”

Irrigation seminar

It’s important that the entire irrigation industry, whether at producer, designer or supplier level, does its part to ensure that continuous innovation takes the industry forward. If we don’t continue to find new ways to apply water and develop new technology that increases water­use efficiencies, producers won't be able to keep up with the demand for food with the limited resources at their disposal.

“The industry has developed rapidly and circumstances have changed,” Netafim South Africa marketing manager Willem Botha says. “It’s important that knowledge is transferred to the next generation. Netafim is planning to host a seminar in partnership with Vinpro and other role players later this year. Important topics that will be discussed include soil mapping, terroir definition, viticultural planning, the impact of climate, water and soil in fertigation, water budgeting and scheduling, soil preparation and system design. Case studies will include the Welgevallen Training and Research Vineyards (supported by the Gen­Z project). The seminar dates will be announced soon.