Host-Pathogen and Pest Interactions: Virus, Nematode, Viroid, Bacteria, and Pests in Tomato Cultivation

Several pathogens and pests damage tomato plants, and only one and/or more pathogens and pests can coexist in the same plant at the same time. As several numerous pathogens are found in the same plant, the damage to the tomato plants is higher. Pathogens such as nematodes, viruses, viroids, bacteria, and insects adversely affect the growth and development of tomato plants. They may infect roots or upper part of the plant and can cause not only slow down the growth of plants, but also crop losses and their death. Damaging of plant caused by pathogens and pests reduces the market value of plant products. Those pathogens and pests are also called biotic stress agents. The damage, mode of infection, and the mechanism of infection in each tomato plant and pathogens might be different. This situation is crucially important to understand plant pathogen relationship in detail in terms of controlling pests and pathogen. The effect of each pest/pathogen on tomato plants during the cultivation, the type of damage, and new developments and perspectives on morphological and molecular aspects in tomato-pathogen interactions will be discussed in this chapter.