Two approaches (field sampling and miniculture) were used to identify vegetable and field crops and other plant species which regulate population levels of Burkholderia cepacia in organic soils cropped to onions, and for rotation with onions to reduce the occurrence of bacterial canker and sour skin of onions caused by the pathogen. It was found that crops such as corn and soybean may aggravate disease incidence if used in rotation to onion, whereas other crops such as radish, lettuce, beets, carrots, millet, and carrot and turnip may offer profitable and disease-ameliorating rotation alternatives. Furthermore, baseline trends are becoming apparent that allow the comparison of cropping strategies from one field to another as relating to the population levels of B. cepacia that the fields support.