The effect of mixed cropping practice of chili bird (Capsicum frutescens L.) on crop yield and pest and disease occurrence

t. Field experiments were performed to compare the effectiveness of four different mixed cropping in reducing pest and diseases incidence and to compare crop yield on chili bird. The four mixed cropping were chili bird – lettuce – cauliflower – tomato, chili bird – cauliflower – tomato, chili bird – tomato and sole chili bird as a control. The experiment was conducted at the Indonesian Vegetables Research Institute (IVERGRI) Lembang - West Java from September 2013 to April 2014. The experiment was arranged as a split plot complete randomized block design with three replications. Result of this experiment revealed that six pest and diseases were recorded such as thrips, mite, white fly, cercospora leaf spot, phytophthora blight and anthracnose. Although the population and/or plant damage due to these pest and diseases were lower in chili bird mixed-crop, however, there were no significant difference in plant damage between chili bird sole crop and mixed-crop except for whiteflies. Among the test treatments, the highest suppression of thrips, whiteflies and mite were observed at conventional system (farmers practice) followed by ATECU at 10 mL/L and IPM treatments. Applications of ATECU and spinetoram in IPM system reduced used of synthetic insecticide 42.86 %. Yield of chili bird varied with different mixed cropping practice. Significantly the highest yields were obtained in chili bird sole crop (5.06 tha-1 ). Mixed cropping between chili-lettuce-cauliflower-tomato reduced marketable yield of chili more than 22.95% however provide additional net income compare to another treatment (Rp. 204.162.500,- per ha) and benefit cost ratio (B:C ratio) 2.53. The lowest net returns Rp. 88.772.500 and B:C ratio 2.01 were obtained in sole chilli. This obviously reflected the importance of mixed cropping to increase the productivity per unit area. Further, it also offers insurance against crop failure. This supports the point that mixed cropping may be an efficient ecological strategy to control pest and diseases and should be incorporated in sustainable agricultural management practices.