Management of and future perspectives on plant parasitic nematodes associated with Narcissus grown in the UK

Plant parasitic nematodes (PPNs) have a negative impact on a broad range of UK-grown ornamental crops, including Narcissus. As a consequence of direct damage through infection and feeding, the nematodes Ditylenchus dipsaci, Pratylenchus penetrans, and Aphelenchoides subtenuis can cause a reduction in the viability, quality, and marketability of bulbs and flowers. Management practices such as lifting after two, three, and four years, limited rotations, and bulk handling predispose Narcissus to nematode attack. To mitigate the impact of PPNs, growers rely on pre-planting methods such as hot water treatment, quarantine/field sanitation, and nematode-free bulbs, as there are no available nematicides with label permission for use on Narcissus. However, these management options, coupled with the legislative removal of synthetic nematicides, are insufficient to manage PPNs of Narcissus. Furthermore, hot water treatment can damage bulbs, and the lack of available land for Narcissus production leads to constrained rotations. Plant parasitic nematodes and associated diseases infecting UK ornamental crop production are generally an understudied area. Here, we review the current status of nematodes associated with Narcissus in the UK, their pathogenicity and management, and highlight areas of potential research towards sustainable management of nematodes in Narcissus.