Sustainable Management of Soilborne Diseases of Horticultural Crops

Soilborne diseases pose significant challenges in maximizing the yield potential of improved cultivars across various horticultural crops. Managing these diseases is particularly challenging due to the pathogens’ ability to persist in the absence of a host for extended periods, a broad host range encompassing weeds, limited efficacy or impracticality of chemical control, difficulties in developing resistant plant varieties, the heterogeneous incidence of these diseases, and a lack of awareness regarding the epidemiological aspects of soilborne pathogens. These pathogens can endure for several years by forming persistent structures such as microsclerotia, sclerotia, chlamydospores, or oospores in the absence of a host plant. Accurately diagnosing soilborne diseases proves challenging, compounded by the microscopic size of the organisms and the nonspecific symptoms of infection. The difficulty in in vitro culturing further complicates accurate identification. Given their inconspicuous nature and the absence of visible symptoms, soilborne organisms often escape the attention of growers and plant protection workers. Although cultural practices have been employed to reduce losses from soilborne and above-ground diseases based on observations and generational experience, claiming absolute “control” over these diseases in agriculture remains rare. As agriculture diversifies its crop portfolio, there is an increasing need to extend methods that effectively mitigate soilborne illnesses. Comprehensive research into the persistence and dissemination of soilborne diseases, the impact of environmental factors, the role of cultural practices, and understanding host resistance and susceptibility becomes paramount for effective disease control. This chapter aims to consolidate the latest insights on diverse practices for managing soilborne diseases, encompassing strategies such as crop rotation, soil solarization, soil amendments, hydroponics, soilless growing systems, grafting, biological control, utilization of natural compounds, and chemical control.