This study investigated the effects of Potato Golden Cyst Nematode (Globodera rostochiensis) on plant development and tuber yield in naturally infested fields with and without nematicides. The study was arranged in a randomized block design in the Alay district of Niğde province in 2021. In the study 4 varieties (PAE 13-08-07 clone, Ünlenen, Leventbey, Muratbey) developed by Niğde Potato Research Institute and two controls (Desiree and Bettina) were used. 50% emergence time, 50% flowering time, number of stems per plant, plant height, tuber maturation time, number of large tubers in total tuber and tuber yield per hectare were examined in potato varieties. No difference was detected in 50% emergence time, number of stems per plant and 50% flowering time in potato varieties in the nematicide-applied area and the nematode-infested area. Varieties were affected by nematicide application at varying rates in terms of plant height and tuber maturation time. The most significant increase in tuber size and tuber weight was observed as a result of nematicide application in the field infested with Potato Golden Cyst nematode.