Comparison of the Injury of Potato Tuber Moth, Phothorimaea operculella (Zeller), on Nine Potato Cultivars and the Effect of Hilling up and Changing the Harvest Date on the Control of the Pest

Potato tuber moth, Phothorimaea operculella (Zeller), is one of the most damaging pests of potato especially in the tropical and sub-tropical regions of the world. Management of this pest is commonly based on chemical control, but due to activity of the pest larvae inside the tubers chemical control of the pest is usually unsatisfactory. Therefore, the use of alternative and more efficient methods are necessary. In this study, the potato moth injury on nine cultivars of potato including Marfona, Sprit, Fontane, Agria, Jelly, Bamba, 82-10, S-12, and S-16 was assessed in the farm and greenhouse conditions. The effect of two important cultural factors including re-hilling of the soil and four different harvesting times were also evaluated against the potato tuber moth damage. The lowest and highest numbers of larval entry holes were observed on the cultivars Jelly and Marfona respectively. Also the samples taken from the plots that had been re-hilled displayed that there was significant differences in the contamination values (percentage of larvae holes) and there was less contamination for treatment groups. Also, the results obtained from samples taken on different harvesting dates showed that the lowest and highest percentages of infested tubers were in the harvesting dates of August 23 and October 7, respectively. Based on the results of present study, along with utilization of the Jelly and S-12 cultivars, the re-hilling of the plant and early harvesting of the tubers in late August are recommended to reduce potato tuber moth damage.