Rating of the likelihood of pest freedom	Very frequently pest free (based on the median)
Percentile of the distribution	5%	25%	Median	75%	95%
Proportion of pest‐free tubers	9,549 out of 10,000 tubers	9,714 out of 10,000 tubers	9,856 out of 10,000 tubers	9,953 out of 10,000 tubers	9,996 out of 10,000 tubers
Proportion of infested tubers	4 out of 10,000 tubers	47 out of 10,000 tubers	144 out of 10,000 tubers	286 out of 10,000 tubers	451 out of 10,000 tubers
Summary of the information used for the evaluation	Possibility that the pest could become associate with the commodity N. aberrans is a currently regulated plant parasitic quarantine nematode that poses a high risk to EU agriculture when introduced either with infested plants (plants for planting) or with soil attached to plants. The nematode is widespread in oca and ulluco production areas (Bridge et al., 2005) and is considered the most common pest of potato and other Andean crops, including ulluco in the temperate Andean highlands (Manzanilla‐Lopez et al., 2002; Franco and Main, 2008). In the Andes it is associated with potatoes at temperatures of 15–18°C (Mai et al., 1981). Although ulluco roots can be severely attacked, information on the economic impact of N. aberrans as a limiting factor of ulluco production is poorly understood (Bridge et al., 2005). It is reported that N. aberrans causes damage to potatoes in Peru, but reports of such attacks are rare. It is uncertain how many fields in the potato‐, ulluco‐ and oka‐growing areas in Peru are affected by N. aberrans. The main pathways of this nematode are plants for planting, including tubers, water, soil and growing media attached to agricultural machinery, tools and shoes. This nematode may be present on ulluco plants or other host plants (e.g. oca) occurring in the environment and may infest the commodity mainly by human‐assisted dispersal.
	Measures taken against the pest and their efficacy The relevant proposed measures are: (i) Surveillance and monitoring, (ii) Sampling and laboratory testing, (iii) Use of healthy propagation and production material, (iv) Sorting/grading/tuber selection, (v) Removal of soil from tubers (brushing/washing) and vi) Pre‐consignment inspection. Interception records There are no records of interceptions from Peru, but see Section 4.3 above for details. Shortcomings of current measures/procedures Peru's answers to the questions raised by the working group state that the production areas of ulluco are located at high altitudes and therefore at low temperatures, which in their opinion means that the nematodes do not pose significant phytosanitary problems. The producers do not perceive the problems caused by pests and therefore do not apply specific phytosanitary measures against nematodes. In view of the process of inspection and phytosanitary certification developed by SENASA, a sample of 2% of the total quantity of ulluco tubers intended for export is taken. This sample is visually inspected and, if pests are suspected, it is destroyed at the laboratory analysis level. However, as there may be mobile stages of N. aberrans in the tubers, the visual inspection may not be sufficient for inspectors to identify infected tubers and send them for laboratory analysis. It is therefore uncertain to what extent this procedure is able to ensure the absence of N. aberrans in asymptomatic tubers. The undetected presence of this nematode during inspections may contribute to the spread of infection with N. aberrans. Main uncertainties No details are given on the distribution of N. aberrans and its frequency in the area of ulluco production. There is some uncertainty regarding the lack of data from official surveillance surveys and reports of problems caused by this nematode in the production of ulluco in Peru. There are uncertainties about the possible infestation with common weeds in the area, which is a good host for this nematode. The absence of nematode‐induced symptoms (bile) is possible in certain plants, so that the presence of N. aberrans in the ulluco tubers cannot be detected by visual inspection.