Potato Cyst Nematode: Resistance, Management, and Quarantine Perspectives Across the Globe

One of the most prevalent and commercially relevant nematode species connected to potatoes is the potato cyst nematode (PCN). In a majority of the world’s potato-growing regions, PCNs have become a major pest. They are known to be present in more than 80 countries with temperate climates. They are also known to infest potatoes grown in cooler regions of subtropical and tropical countries and can bring about yield losses of up to 70%. PCNs are members of the genus Globodera, which includes two species, Globodera rostochiensis (Woll) and Globodera pallida (Stone), as well as eight pathotypes (Ro1-Ro5 of G. rostochiensis and Pa1-Pa3 of G. pallida). The host root leachate induces juveniles to emerge from cysts, and second-stage juveniles (J2s) penetrate the apex of the elongation zone in potato roots and migrate intracellularly into the cortex surrounding vascular tissue. Mature cysts separate from the roots and can remain in the soil for several years. In general, evidence of mineral deficiencies, spotty yellowing of plants, withering of plants in the sun, and stunted plants with weak root systems are symptoms of advanced PCN infection. In many parts of the world, strict quarantine measures are in place to regulate and prevent the spread of PCN, as this pest is extremely challenging to eliminate once ensured in the field. Apart from nematicides, cultural methods such as rotation of host crops with non-host agriculture, inter-cultivation with antagonist crops, cultivating resistant cultivars, and the warmer months ploughing help prevent and reduce the damage caused by PCNs. However, many cultural management strategies are rendered ineffectual due to the persistence of cysts in the soil, even in the absence of host crops. Growing environmental concerns limit the use of hazardous pesticides for PCN control. Therefore, the most desirable and efficient management approach is an integration of different management strategies.