Relationships between Mineral Nutrition and Plant Diseases and Pests

Abstract

Depending on the mineral nutrient (or beneficial mineral element), the nutritional status of the plants, host plant species, and type of pathogen and pest, mineral nutrition might affect resistance or tolerance. This chapter includes examples of the effects of mineral nutrition on both resistance and tolerance. In this context mineral nutrition of plants can be considered as an environmental factor that can be manipulated relatively easily. Although frequently unrecognized, this factor has always been an important component of disease control. The influence of mineral nutrition on plant resistance is relatively small in highly susceptible or highly resistant cultivars, but very substantial in moderately susceptible or partially resistant cultivars. The close correlation between nitrogen supply and leaf blotch, however, cannot be generalized to all fungal and parasitic diseases. The interactions between higher plants and parasites and pests are complex, and to provide a short outline of the role of mineral nutrients in these interactions requires considerable simplification. This chapter tries to highlight these interactions with a few representative examples in order to demonstrate both the potential possibilities and the limitations of disease and pest control by mineral nutrition and fertilizer application. Comprehensive reviews on this subject have been presented, either at a general level of micronutrients, or for particular mineral nutrients such as nitrogen, potassium, and manganese.