Relationship between mineral nutrition, plant diseases, and pests

Abstract

Mineral nutrient supply or tissue concentrations affect plant diseases and pests in various ways. The supply of nutrients changes the resistance of plants to pathogens and pests by altering growth and tissue composition (e.g., concentration of soluble compounds or defense compounds), the expression of plant defense and pathogen/pest virulence genes, and the interactions with beneficial soil microorganisms. Depending on the pathogen or pest and nutrient, adequate nutrient supply for optimal plant growth may increase or decrease disease incidence. This chapter discusses the effects of nutrient supply on foliar and soil-borne fungal and bacterial diseases as well as on pests. Calcium and B inhibit pathogen invasion via their stabilizing effect on cell walls and membranes. Silicon and Mn play important roles in defense reactions to pathogen infection or pest attack, whereas N and K exert their effects mainly via modulating the concentrations of soluble compounds in plant tissues. The effects of crop management (e.g., timing and form of fertilizers, liming, and/or biological agents) on disease incidence are outlined.