Nematode parasites of potato and sweet potato.

Abstract

This chapter describes the nematode parasites of potato (Solanum tuberosum) and sweet potato (Ipomoea batatas). Information is given on their origin and distribution, biology, symptoms of damage, spread, environmental factors affecting parasitism, other hosts, disease complexes, economic importance, and management measures, which include host resistance, cultural, chemical and biological control methods.

Current occurrence and prevalence of root-knot nematodes species, Meloidogyne spp. Goeldi, 1892 (Tylenchida: Meloidogynidae) in ware potato fields of Turkey

“…Depending on the nematode density and species, infested roots and tubers may have galls of varying sizes and shapes. Meloidogyne chitwoodi and M. hapla produced galls that are normally smaller than those induced by other species (Niere & Karuri, 2018). Even 5% necrotic spotting in the flesh of tubers makes them commercially unacceptable for the fresh market.…”

“…Considered one of the most promising products in the fight against hunger and poverty, potatoes are highly recommended by FAO as a food security crop due to the growing population and food demand (Thomas & Sansonetti, 2009). Potato crops are damaged by numerous pests and pathogens, including nematodes (Niere & Karuri, 2018). Plant-parasitic nematodes are one of the crucial factors restricting potato yield and quality in many potato-growing areas (Lima et al, 2018).…”

“…There are no reports of specific aboveground symptoms in potato associated with root-knot nematode infestation, however varying degrees of stunting, yellowing, and wilting under moisture stress can be seen in some of the infested plants. Root-knot nematodes reproduce on potato roots and tubers, but the size and shape of galls or knots could vary depending on the species and density of nematodes (Niere & Karuri, 2018). The economic threshold on potato cultivation in the USA and the Netherlands are 1 and 10 J2s/100 ml soil for M. chitwoodi, respectively (Brodie et al, 1993;Norshie et al, 2011) and 50 eggs/250 ml soil for M. hapla (Brodie et al, 1993).…”

Potato Cyst Nematodes: A New Threat to Potato Production in East Africa

“…In Kenya, the crop represents a source of income for around 2.5 million people across the value chain (Abong and Kabira, 2013), with between 500,000 to 780,000 people directly involved in potato farming activities (Janssens et al, 2013). PCNs are highly destructive pests of potato, resulting in major losses to production and incurring significant investment toward their management (Niere and Karuri, 2018). They are indigenous to South America but have since become established in various potato growing regions around the world (Brodie et al, 1993;Hodda and Cook, 2009).…”

“…The situation is not helped by the emergence of new pests and diseases, such as the recently detected potato cyst nematodes (PCNs) Globodera rostochiensis and G. pallida (Mwangi et al, 2015;Mburu et al, 2018). PCNs are subject to strict quarantine regulations in over 100 countries (EPPO, 2017) and are globally considered as the most important pests threatening potato production but are all too often overlooked in less developed countries (Coyne et al, 2018;Niere and Karuri, 2018). The quarantine status of PCNs is, in part, related to their ability to produce quiescent structures known as cysts that consist of the hardened body of the females measuring ∼0.5 mm in diameter enclosing ∼300-500 eggs each.…”