Nematode problems in tuber crops and their sustainable management

Abstract

In many subtropical and tropical countries, the most significant food commodities produced are those that are grown from tubers and roots (R&T). The R&T include yams (Dioscorea spp. L.), cassava (Manihot esculenta Crantz), and sweet potato (Ipomoea batatas (L.) Lam.) and edible aroids such as Taro (Colocasia esculenta Schott.) and Tannia (Xanthosoma sagittifolium Schott.). These crops represent the second-largest global source of carbohydrates, after cereals, in the tropical world, with a projected two billion people in Asia, Africa, and Latin America relying on them for food, feed, and income. Around 45% of R&T crop production is used for human consumption, with the remaining 55% going to either the production of animal feed or industrial processing that results in products such as starch, distilled spirits, and a variety of other minor products. The R&T produce starchy-storage organs known as rhizomes, corms, or tubers, which are modified stems or roots. Their production is hampered by a variety of biotic and abiotic factors. Plant parasitic nematodes (PPNs) are one of the important biotic factors that reduce the yield or quality of tubers. This chapter discusses the major PPNs affecting R&T in the subtropical and tropical regions, symptoms and damages caused, long-term management measures to combat the threat posed by nematodes, and future prospects.