DEFENDER: A HIGH-YIELDING, PROCESSING POTATO CULTIVAR WITH FOLIAR AND TUBER RESISTANCE TO LATE BLIGHT

Authors: Novy, Richard - Rich; LOVE, S. - UNIV OF ID, ABERDEEN; CORSINI, D. - RETIRED USDA/ARS ABERDEEN; PAVEK, J. - RETIRED USDA/ARS ABERDEE; Whitworth, Jonathan; MOSLEY, A. - OR STATE UNIV CORVALLIS; JAMES, S. - OR STATE UNIV REDMOND; HANE, D. - OR STATE UNIV HERMISTON; SHOCK, C. - OR STATE UNIV ONTARIO; RYKBOST, K. - OR STATE UNIV KLAMATH FAL; Brown, Charles; THORNTON, R. - RETIRE WA ST UNIV PULLMAN; KNOWLES, N. - WA STATE UNIV PULLMAN; PAVEK, M. - WA STATE UNIV PULLMAN; OLSEN, N. - UNIV OF ID, TWIN FALLS; INGLIS, D. - WA STATE UNIV, MT VERNON

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2005
Publication Date: 1/1/2006
Citation: Novy, R.G., Love, S., Corsini, D.L., Pavek, J.J., Whitworth, J.L., Mosley, A.R., James, S.R., Hane, D.C., Shock, C.C., Rykbost, K.A., Brown, C.R., Thornton, R.E., Knowles, N.R., Pavek, M.J., Olsen, N., Inglis, D.A. 2006. Defender: a high-yielding, processing potato cultivar with foliar and tuber resistance to late blight. American Journal of Potato Research. 83:9-19

Interpretive Summary: The potato cultivar ‘Defender’ is high-yielding, white-skinned, and notable for having foliar and tuber resistance to late blight infection caused by Phytophthora infestans. It was released in 2004 by the USDA-Agricultural Research Service and the Agricultural Experiment Stations of Idaho, Oregon, and Washington. Defender is suitable for processing into French fries and other frozen potato products directly from the field or from storage. Defender also may be used for fresh markets in regions such as California, where cultivars with long tubers and white skin are traditionally grown. Resistances to late blight and other potato diseases make Defender an ideal candidate for organic potato production. Starch and Vitamin C content of tubers of Defender are consistently high. In addition to late blight, Defender also is resistant to tuber early blight, potato virus X, and net necrosis; it has moderate levels of resistance to Verticillium wilt, pink rot, foliar early blight, corky ringspot, and Erwinia soft rot. Defender is susceptible to scab (common and powdery) and potato leafroll virus; it has moderate susceptibility to dry rot and potato virus Y. Susceptibilities to internal necrosis, tuber greening, and blackspot bruise also have been noted, but may be minimized through cultural and harvest practices.

Technical Abstract: The potato cultivar ‘Defender’ is high-yielding, white-skinned, and notable for having foliar and tuber resistance to late blight infection caused by Phytophthora infestans (Mont.) de Bary. It was released in 2004 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington. Defender is suitable for processing into French fries and other frozen potato products directly from the field or from storage. Defender also may be used for fresh markets in regions such as California, where cultivars with long tubers and white skin are traditionally grown. Resistances to late blight and other potato diseases make Defender an ideal candidate for organic potato production. Defender consistently produced greater total and U.S. No. 1 yields than ‘Russet Burbank’ in Idaho trials. In early harvest trials conducted in the western U.S., average total yields of Defender were 17% and 23% greater than yields for Ranger Russet and Shepody, respectively. In full-season trials conducted in the western U.S., Defender averaged 10% and 15% higher yields than Ranger Russet and Russet Burbank, respectively. Specific gravity of Defender is consistently high, with values comparable to those of Ranger Russet; ascorbic acid (Vitamin C) levels are also high in the tubers. In addition to late blight, Defender also is resistant to tuber early blight [Alternaria solani, (Ellis & G. Martin), L.R. Jones & Grout], potato virus X, and net necrosis; it has moderate levels of resistance to Verticillium wilt (Verticillium dahliae, Kleb), pink rot, foliar early blight, corky ringspot, and Erwinia soft rot. Defender is susceptible to scab (common and powdery) and potato leafroll virus; it has moderate susceptibility to dry rot (Fusarium spp.) and potato virus Y. Susceptibilities to internal necrosis, tuber greening, and blackspot bruise also have been noted, but may be minimized through cultural and harvest practices.