By Diane Silcock
WITH the recent heavy rainfall experienced in the Western Cape, it’s easy to lose sight of the drought that plagued the province in 2018. However, it remains fresh in the minds of fruit farmers in particular, with South Africa being one of the five biggest exporters of apples globally.
“South Africa being a water-scarce country, the 30th driest in the world, and having 98% of its available freshwater resource already allocated, and with over 60% of this water used in agriculture, the Water Research Commission (WRC) commissioned the Council for Scientific and Industrial Research (CSIR) to develop a tool that guides apple farmers to use water more efficiently,” says Dr Luxon Nhamo, research manager at WRC.
CSIR senior researcher, Dr Mpumi Mobe, says that the WRC’s mandate was for the CSIR to develop a smartphone app that forecasts the water requirements of apple orchards from one to seven days in advance. Farmers want to know that if they reduce the amount of water they apply, that it will not affect production. The app ensures that they do not under-irrigate or over-irrigate their crops, thus saving water, without affecting production.
Dr Nhamo expressed that with apple cultivation you have huge water losses through virtual water. The app guides farmers on when to/not to irrigate and with how much water. “This water use efficiency app has become an integral part of irrigation scheduling in apple production, besides being critical for saving nutrients and energy.”
Dr Sebinasi Dzikiti, now senior lecturer in the department of horticultural science at Stellenbosch University, was involved in the developmental phase of the pilot project where he worked with Riverside Farm in Villiersdorp and Oak Valley farm in Grabouw.
“Over the years, researchers from the CSIR in collaboration with fruit industry partners have conducted research aimed at measuring the actual water use of orchards using state-of-the-art techniques. This app is a culmination of those efforts as it pulls this data together to develop a tool that is both accurate and simple. Currently the app is designed to forecast the water requirements in apple orchards only. Other crops will be added in future.”
Dr Dzikiti says that the number of tools available to farmers to optimise their irrigation is growing, mostly by harnessing modern technologies, therefore the CSIR water use app adds to the existing products.
Dr Mobe confirms the CSIR’s plans to commercialise the app, and that research is currently under way to assist vegetable small-holder farmers, in a similar way, especially in Limpopo province.
Western Cape farmer, Shawn Spinnler, who participated in the pilot project on Riverside Farm in Villiersdorp, gives insight into the benefits of the app. “In apple orchard farming, determining our irrigation schedule is very important. The roots need to stay in contact with the soil through the water. If there’s too much water, there’s no oxygen.
“The CSIR water app is helping us to accurately determine a reference statistic with water per day scheduling based on climatic responses. Measuring radiation, temperature and wind, and taking all those crop factors into the equation, gives you more or less a baseline of what the tree will require water-wise per day, in order to keep the functions active within the tree. It’s much easier having it all on a one simple app rather than in multiple spreadsheets.”
