Investigation of the effect of potato golden cyst nematode, Globodera rostochiensis on potato yield

Potato golden cyst nematode Globodera rostochiensis (Wollenweber) Skarbilovich (Tylenchida: Heteroderidae) is one of the most economically important potato pests in the world. Usually, surveys are routinely carried out for these nematodes to determine their distribution and density in potato growing areas. Morphological and molecular analysis are used to make identification of this nematode and to create control strategies. In this study, it was shown that 96% of the soil samples taken during the potato growing seasons in Bozdağ and Ödemiş locations of İzmir province in 2017 and 2018 were infected with G. rostochiensis. The average number of cysts in the contaminated areas ranged from 0.01 to 3.70 cyst/g soil. The observation of the morphological and morphometric characters of the second stage juvenile and cysts of Globodera rostochiensis revealed differences between the populations obtained from Bozdağ and Ödemiş area. Molecular identification of nematodes was made based on the ribosomal gene region. As a result of morphological measurements and phylogenetic analysis, it was determined that there are small differences between the populations collected from Bozdağ and Ödemiş area. In this study, the impact of G.rostochiensis on the potato yield from the plots treated with different nematicide were also investigated. As a results, the highest yield increase, with 34.35% were achieved from the nematode controlled plots from Ödemiş population treated with combination of Fostiazate 900 g/L pre plant plus 45 days after that application, followed with 31.51% yield increase treated with Fluopyram 400 g/L pre plant application, and with 27.13% yield increase from the nematode controlled plots from Ödemiş population treated with Fosthiazate 900 g/L preplant application. The results of this study will help to better understand the physiology, ecology and biology of the nematode in order to cope more effectively under farmer conditions.