Introduction

Abstract

The development of horticultural production systems is thought to have had a major influence on human history. Von Hagen (1957) speculated that ‘the transition of human communities from nomadic hunter-gatherers to sedentary or semi-sedentary horticultural communities’ was partly determined by the start of crop cultivation on a small scale around human dwellings. Horticulture is a sector of agriculture in which plants are primarily grown to serve as food (fruits and vegetables), herbs or medicinal plants (cannabis, garlic) or for hedonistic pleasure (ornamental plants). Horticulture comes from the Latin words hortus (= garden) and cultura (= managing). Nowadays, horticultural production is often extremely intensive and highly concentrated in certain areas. Examples of these regions are California (USA), Andalusia (Spain), the Netherlands or the Shandong province in China. The horticultural and medicinally produced goods are mostly highly perishable. Reasons for this are, for example, the high surface-area-to-volume ratio of, for example, leafy greens (Watada et al. 1996). Processing and/or distribution should therefore take place as quickly as possible and may require extra cooling in the 0–10 °C range (Watada et al. 1996). This maintains freshness and preserves health-promoting characteristics of certain substances. Otherwise, the nutritive value and/or activity and amount of pharmaceutically active substances might decrease because of time delays, transport distance or postharvest temperature. Important attributes that determine the nutritive value (inner quality) of vegetables are the amount and nature of carbohydrates, proteins, lipids, fibres, vitamins, minerals or other secondary metabolites (◘ Fig. 1.1). Secondary metabolites have several functions and important for the stress response of plants to environmental factors (see ► Chap. 3). As many of these secondary metabolites are phytochemicals, they can sometimes be used to modulate human health. This textbook focuses on horticultural strategies to enrich these compounds within vegetables and medicinal plants without decreasing their yield. The inner quality of crops can also be affected by a plant’s uptake of drug residues or agrochemicals. Factors determining the outer quality of horticultural crops are size, shape and colour (◘ Fig. 1.1). These outer quality features will not be discussed in this book.