Fertilization and Susceptibility of Lettuce and Tomato Crops to Pests and Pathogens

The paper investigates the role of nitrogen fertilization in managing plant health and susceptibility to major bioaggressors in lettuce and tomato under commercial production conditions. It shows that splitting nitrogen inputs and accounting for soil reserves can limit lettuce exposure to Sclerotinia spp. and aphids without reducing yield. In tomato, low nitrogen levels increase susceptibility to Botrytis cinerea but decrease powdery mildew attacks. The PILazo® tool for greenhouse tomato enables at least a 30% reduction in nitrogen use without compromising yield or increasing disease risk. In soilless culture, adjusted nutrient solutions likewise preserve production potential and plant health. These findings support lower-risk integrated strategies combining rational nitrogen management, biological control, and varietal choice.