Screening of Potato Varieties for Resistance to Potato Tuber Moth, Phthorimaea operculella (Zeller) in Meghalaya, India

Fifteen commonly grown potato varieties in Meghalaya, consisting of nine local and six commercial varieties, were screened for their susceptibility against potato tuber moth, Phthorimaea operculella. Based on four parameters, oviposition preference, feeding preference, percentage of survival and number of mines, the varieties were categorised into highly susceptible (HS), moderately susceptible (MS), slightly susceptible (SS), and slightly resistant (SR). Among the 15 varieties, two varieties, Kufri Jyoti and Kufri Megha, were highly susceptible (HS) and only one variety, Lah Ksain, was slightly resistant (SR) based on all the tested parameters. Number of eggs laid had a significantly positive correlation with number of eyes and number of mines. The varieties preferred for feeding had more mines compared to the less preferred ones as indicated by the high positive value of the correlation coefficient between penetrating larvae percentage and number of mines. Overall, the results indicated that the local varieties performed comparatively better than the commercial varieties in terms of the parameters studied.