5. How to change the amounts of compounds with nutritional value in plants?

In this chapter a general explanation of effects of cultivation practices on plants is provided (§5.1). In §5.2 the effects of fertilizers are discussed with the focus is on the minerals: potassium, calcium, iron, zinc, and selenium; and in §5.3 information on the impact of soil health is discussed followed by a discussion on the impact of §5.4 biological farming on the nutritional value of crops. In §5.5 the relation between secondary metabolites: carotenoids (pro-vitamin A), Tocopherols (vitamin E), key phenolic compounds (e.g. flavonoïds), phytate (Phytic acids) and Vitamine C and light is covered. This is followed by a section (§5.6) with examples of the impact of cultivar choice on the nutritional value for humans and a general section (§5.7) on the effects of post-harvest conditions on nutritional value.

As a rule of thumb, if growers moderately stress crops several physiological responses will follow. Examples are the synthesis and accumulation of bioactive metabolites (ascorbate, carotenoids, glucosinolates, phenols, polyamines and phenols) which can enhance the tolerance to abiotic stresses (Orsini et al. 2016).