Faiza Salah, Abdin Zein Elabdien, Hayder Abdelgader:
Varietal Susceptibility of Potato to the Black Cutworm, Agrotis ipsilon (HFN) (Lepidoptera: Noctuidae)

FAIZA SALAH¹, ABDIN ZEIN ELABDIEN², HAYDER ABDELGADER^3
1University of Gezira, Crop Protection Department, Sudan
²University of Khartoum, Crop Protection Department, Sudan
³Agricultural Research Corporation, Crop Protection Research Center, Sudan

The black cut worm (BCW) Agrotis ipsilon (HFN) (Lepidoptera: Noctuidae) is a highly polyphagous pest of several wintery crops and became a major potato pest on lighter soils in Karari, Khartoum state, Sudan. The black cut worm inflicts serious damage on the tubers, resulting in drastic yield losses. Despite its economic importance, little attention has been directed to this pest in Sudan.

Field experiments were conducted during two seasons in Karari, to evaluate 10 potato varieties (lines/accessions: Desiree, Spunta, Alpha, Draga, Mondial, Lesita, Ajax, Famosa) for resistance to BCW damage. The percentage of damaged tuber numbers (% DTN) and weight (% DTW) were used as parameters for evaluation. Differences in both parameters were very highly significant, between varieties and seasons (p < 0.001 for both parameters). The interaction between the varietie (lines/accessions) and seasons was also highly significant (p < 0.001). Two parameters were found to correlate strongly and significantly (r = 0.83).

The 10 potato varieties (lines/accessions) were also subject of a series of no-choice tests in the laboratory during two seasons. The tests included testing the larval and pupal developmental rates on potato tubers. Significant differences were noted in larval weight gains (LWGs), due to differences in potato varieties across the various feeding tests. Alpha, Lesita, Bright varieties showed higher levels of resistance both in the field and in the laboratory, while Desiree and Spunta showed highest level of susceptibility. Factors governing the causes for resistance are discussed.

Keywords: Agrotis, black cut worm, potato, Sudan

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Contact Address: Faiza Salah, University of Gezira, Crop Protection Department111, 111111 Wad Medani, Sudan, e-mail: faizarubayahoo.com