Members projects

Sustainable growing of potatoes for the processing industry in South Africa focuses on management practices to limit the cost of production and risks due to adverse climatic conditions, limited water resources, emerging diseases (brown spot, PVYNTN and powdery scab) and losses due to common scab and nematode damage.

The focus of this project is profitable production of potatoes in ways that are more environmentally friendly. To attain this objective, crop management practices are guided by decision support systems to improve resource use efficiencies and thus reduce greenhouse gas emissions into the atmosphere. The following decision support systems are used:

- The Cool Farm Tool is used to determine a baseline of CO2 emissions and to identify the main contributors which drive the project. Data of six growers showed that “Crop Management” contributes 51% to the total CO2 emissions per ha while “Field Energy Use” and “Cooling and Storage” contribute 41% and 6% respectively. The high percentage of “Field Energy Use” is the result of one grower who has fields relatively far apart leading to high transport inputs. The largest impact can therefore be made by focussing on the contribution of “Crop Management”.

- The production of seed potatoes is intensive due to the threat of aphids and the resultant virus infection of the seed tubers. A network of Rothamsted suction traps in the major seed growing areas is used to determine the periods of peak aphid flights and therefore the increased risk of virus infection of potatoes. This information together with the number of aphids caught in yellow bucket traps, guides optimum dates for planting and killing of foliage. Lessons learned clearly show that the dependence on chemical control alone has limited success in the control of insects and often leads to over-application of pesticides.

- The Dacom Agri Yield Management (AYM) system, utilising soil moisture content, temperature, leaf wetness, solar radiation, rainfall and wind speed and wind direction data collected through telemetry is used in various models to supply the grower with guidelines to make informed decisions regarding irrigation, pesticide application and nitrogen needs of the crop. McCain Foods SA has a history of success with the Dacom systems in various environments.

A culture of working towards sustainable production, demands leadership and trust between processor and suppliers. A forum for technology exchange was established where extension officers and growers learn from each other's experiences but also where the growers can be exposed to the latest developments in technology and information to empower them to make better management decisions. The objective is to focus on success stories to convince more growers to utilise decision support systems, instead of relying solely on traditional practices based on scheduled applications without taking the situation in the field into consideration. This will result in improved profit margins and secure the competitiveness of the industry in the international arena. The consumer at the end of the value chain will benefit by knowing that the product was grown with the best interests of the environment and people involved at heart.

These decision support systems have been established over the past 3 years. The objective for 2011/2012 is to start integrating these systems in order to improve on production cost and the established baseline of CO2 emissions.