Brassicas pest control

Non-crop plants associated with the crop species offer possibilities for allelopathic weed control. In this study Brassica campestris (wild mustard), which is an important weed in Santa Cruz County, and broccoli, a common crop, were intercropped, The allelopathic potential of both species and the changes in this potential throughout their life cycle were demonstrated with experiments in the laboratory. Effects of different planting densities and sowing time of canpestris on the crop yield are analyzed. Preliminary steps to separate the physiologically active compound(s) are described. The possibilities for the use of Brassica campestris in agroecosystem design as a non-crop plant that promotes pest control are described. 

This is the practice of growing related vegetables in different areas of the garden in consecutive years. If crops from the same family—the lettuce family, the brassica family, and so on (see pp.234-253)—are grown in the same place year after year, related soilborne pests and diseases may become established. In small plots, moving vegetables just a few yards may not have much effect on pest and disease control, but it is still worth doing for other benefits. 

The main reason for this rotation method is to avoid the build-up of pests and diseases, which attack plants that are botanically related. Crop rotation also helps to keep a balance of nutrients in the soil—legumes, for example, release nitrogen into the soil and so are good crops to grow before brassicas, which need high levels of nitrogen. The rotation system also helps to control weeds some crops, such as pumpkins and potatoes, have lots of leafy cover that suppresses weeds others, such as carrots, allow weeds to germinate easily. 

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