BACKGROUND The European Union requires growers to implement the principles of integrated pest management ( IPM) by 2014. This paper provides a quantitative overview of the costs and effectiveness of voluntary IPM measures in 15 crops in the Netherlands. The authors will focus on aquatic risks and define effectiveness as the potential to reduce the risks posed to aquatic organisms. They further identify which of these measures have actually been adopted by growers and why certain measures have not been adopted. RESULTS Of the 105 measures evaluated, the most effective measures with respect to risk reduction were emission reduction and replacement of high-risk pesticides (each up to 80% reduction). IPM measures directed towards lowering pesticide use generally showed a smaller risk-reducing potential. However, 40% of these measures reduced the overall cost of pest management. About 60% of all 105 measures were voluntarily implemented by growers. The most commonly adopted measures were pest prevention, low-dose spraying and spray drift reduction. Cost appeared to be an important incentive for adoption; however, other factors such as risk perception, education and practicability were equally important. CONCLUSIONS Voluntary IPM measures have significantly contributed to reducing aquatic risks (15-50% risk reduction, depending on crop type). Further risk reduction could be achieved if more growers were to adopt the most effective measures, such as spray drift reduction and replacement of high-risk pesticides. However, IPM has hardly reduced the number of pesticide applications, and therefore the dependence on chemical crop protection continues to be high. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]