Sustainable and diversified vegetable-based farming systems in highland regions of West Java

Highland areas of tropical countries have an air temperature range suitable for the cultivation of cruciferous plants throughout the year. However, this suitability and, therefore, subsequent adoption of cruciferous plants throughout the year has lead to severe clubroot damage. In Japan, vegetables are also often grown under continuous cropping and damage associated with continuous cropping is frequently observed. In this chapter, the experience of crop rotation and several cultural practices in highland areas to control clubroot damage in Indonesia and Japan are reported. Resting spores of P. brassicae can survive for long periods in soil; however, shortterm crop rotation with corn can alleviate the most severe damage. Recently, it was reported that clubroot damage to Chinese cabbage cultivation has been controlled using trap crops. A combination of resistant varieties of Chinese cabbage and endophyte inoculation also prevented yellows. Crop rotation in one year showed remarkable success in suppressing clubroot damage and with the addition of a fallow period in the dry season; the effect of the crop rotation became more stable for longer periods of time. Plant growth and yield were better in crop rotations than of continuous systems. Although the reduction of clubroot damage differed to some extent, all the non-host plants showed positive results. The combinations of plants in the cropping system are flexible and easily adjusted to farmer conditions.