Turmeric

Turmeric (Curcuma longa L.) is an ancient spice and a traditional remedy that has been used as a medicine, a spice, and as a dye. It is a rhizomatous herbaceous perennial plant belonging to the family Zingiberaceae, which is believed to be native to tropical South Asia. It grows in tropical and subtropical regions throughout the world. India is the main producer and exporter of turmeric in the world. Curcuminoids, a group of polyphenolic compounds present in the turmeric rhizome, are responsible for the yellow color and its medicinal properties. Turmeric rhizome contains 2–8% curcuminoids, and the variation in phytoconstituents is attributed to differences in genotype, climate, and soil condition of different agroclimatic zones. Good genetic variability exists in the crop, and cultivars vary in yield, cropping duration, and quality. More than 70 turmeric types are known to be under cultivation in India. Most of these cultivars go by local names, derived mostly from the place of cultivation. Crop improvement programs in turmeric were limited to clonal selection and mutation breeding for many years, mainly to identify turmeric types with high yield potential, high curing percentage, and high curcumin content. Recombination breeding in turmeric is attempted in a very limited extent to develop improved genotypes. The research achievements of biotechnology and genomics that may result in the development of promising cultivars are highlighted. Turmeric is grown both under rainfed and irrigated conditions. It can also be grown as a component and intercrop with other crops. To meet the increasing world demand for turmeric, it is of utmost importance to increase the productivity with the desired quality parameters at an affordable cost. Different production systems, viz., organic, controlled, and vertical farming, are gaining importance in turmeric cultivation. The crop is harvested 7–9 months after planting, depending on the cultivar, soil, and growing conditions. The scope of this chapter includes the various aspects of botany, taxonomy, cytology, genetic diversity, crop improvement, chemistry, production aspects, and postharvest processing of turmeric. This chapter discusses the turmeric crop holistically under the major headings of origin and distribution; taxonomy; botany; morphology of plant and rhizome; rhizome developmental anatomy; cytology; genetic resources; crop improvement; varieties developed and released; biotechnological interventions; chemistry; curcumin and its derivatives (curcuminoids); various aspects of crop management, crop nutrition, harvesting, processing, and products; functional properties; medicinal uses; culinary uses; and safety issues. The plant protection aspects are discussed in separate chapters.