Effects of aldicarb and oxamyl in peaty loam soil on potato cyst-nematode, Globodera rostochiensis, and on resistant and susceptible potatoes

Summary Potato cyst-nematode, Globodera rostochiensis, was controlled in peaty loam by growing the resistant potato cultivars Cara and Maris Piper, or by incorporating aldicarb or oxamyl granules in the seed bed before planting susceptible cultivars. In heavily infested soils, aldicarb or oxamyl increased tuber yields of susceptible cultivars and Maris Piper but did not increase tuber yields of Cara, which suggests that it is tolerant as well as resistant. Yield responses to oxamyl varied greatly among susceptible cultivars. In the top 20 cm of untreated soil, the nematodes increased twice as much on Bang Edward as on five other susceptible cultivars.