Strategies for minimizing pesticide residues in red currant (Ribes rubrum)

A heavy reliance on synthetic fungicides has been necessary to control postharvest decay of fruits, including soft fruit. Recently, there is an ongoing concern about pesticide residues on fruits. Consumers increasingly prefer fruits without pesticides, and this is used by supermarkets as a selling strategy (residue free fruit). Research is started at Applied Plant Research (WUR-PPO) in order to find strategies for minimizing chemical pesticide use and residues in fruit crops. In the Netherlands soft fruit growers store their red currants for several months in order to obtain good prices. However, post-harvest rots can lead to significant losses. The most important post-harvest diseases are Botrytis cinerea and Penicillium expansum. Evaluation of spraying schedules revealed that red currant growers apply up to 16 spray applications in order to control Botrytis, powdery mildew, aphids and leaf drop disease. The majority of the spray applications during the season are focused on controlling Botrytisinfections. Residue assessments showed that all applied active ingredients will be detected at harvest, and the number of different active ingredients measured is 6 to 10. In 2012 a project was started to develop strategies to decrease the number of spray applications and different chemical products applied. The results of the different strategies on residues, storability and quality of red currant in long storage will be presented.