Occurrence of Potato Cyst Nematode (Globodera spp.) as a Threat to the Potato Crop in Yemen

Abstract

The potato cyst nematode (PCN) (Globodera spp.) was previously regarded as the most detrimental pest to potatoes, causing serious crop losses worldwide. Despite the significance of PCNs, there is currently no data available on their prevalence or the extent of their impact on Yemeni potato cultivation. Therefore, this investigation was conducted to investigate the distribution and population density of this pest in the major potato production regions in Yemen and assess potato yield loss caused by it. During the 2023 production season, a total of 455 soil samples were collected from 145 fields located in 30 regions in Amran, Dhamar, and Ibb governorates. Cysts were extracted using the Fenwick can technique. The results obtained showed that PCNs were detected in all surveyed regions, except for the Daaf region in the Dhamar governorate. This nematode was recovered from 121 fields (83.4%) with densities ranging from 3 to 1,340 cysts/200 g of soil. The highest mean frequency of occurrence (100%), population density, cyst viability, and soil infestation level (SI) were recorded in the Ibb governorate, whereas the lowest mean frequency of occurrence (21.8%), population density, and soil infestation level were recorded in Dhamar governorate. The results obtained also showed significant variation in the mean SI levels of PCN across most of the surveyed fields within regions, in addition to their differences between regions within the governorates. Mean SI levels ranged from 1.4 to 190.3 eggs and juveniles/g soil, resulting in an estimated average yield loss ranging from 0.2 to 26.2 t/ha. The results of soil infestation levels with potato cyst nematodes recorded at seven sites in Ibb Governorate and one site in Amran Governorate revealed levels far exceeding the economic damage threshold, leading to severe yield losses and the failure of potato cultivation in these areas. Thus, there is an urgent need to provide farmers with an appropriate strategy for PCN management.

Keywords:

Globodera, PCNs, distribution, density, yield loss.