Role of cultural practices for the management of soilborne pathogens in intensive horticultural systems

Management of soilborne diseases should be holistic; it should address all sources of the inoculum and should be implemented before, at and after planting. Soilborne diseases are especially severe in intensive systems due to frequent cropping. Therefore, sanitation of the inoculum surviving between crops is essential. Cultural practices should play a role in the management of soilborne diseases, particularly because of the ban on methyl bromide use. Cultural practices can be used alone or as components of pest-management programs. There are three categories of practices for the management of soilborne pathogens: 1) Practices for regular agricultural purposes which can also be used for disease control, e.g. irrigation. 2) Practices which are used solely or mainly for pest control, e.g. sanitation. 3) Practices which can be used for both agricultural purposes and pest control, e.g. crop rotation. The following principles should be followed: 1) Any potential control method may be considered, providing that the method is environmentally, technologically and economically feasible. 2) Combining with other chemical or nonchemical methods, while minimizing pesticide use, should be the goal. 3) Priority should be given to diseases that are difficult to control, or those which involve problematic pesticides, e.g. methyl bromide. 4) Economic considerations should be adopted. Cultural practices for disease management are: crop rotation, flooding, soil solarization, adjusting planting date, irrigation, fertilization, composting, sanitation and others. Physical methods, e.g. heating the soil or propagation material and UV - irradiation of contaminated water, should also be considered when applicable. The emphasis should be placed on practices which can be easily adapted to the crop management of intensive horticultural systems.