The material and labor costs (USD/ha) were recorded for pesticides and other pest-management inputs used during the growing season for each plot in both IPM and non-IPM treatments. Mean cost of production, head yield (t/ha; t ¼ 1000 kg), total returns, net returns and costs of pest management were compared between treatments using t-tests (SPSS version 9.0). Benefit: cost ratios, defined as the total returns: cost of production, were calculated for each treatment, in each year.