Released in 2004, Defender (A90586-11) is high yielding, lightly russeted, and most notable for having foliar and tuber resistance to late blight infection. Defender is suitable for processing into french fries and other frozen potato products directly from the field or from short term storage. Defender is very high yielding and may also be used for fresh markets.
Its resistance to late blight and other potato diseases make it an excellent candidate for organic production. It consistently produced greater total and US No. 1 yields than Russet Burbank. The specific gravity is consistently high, with values comparable to Ranger Russet and tuber Vitamin C levels are also high, with concentrations 69% greater than Russet Burbank.
In addition to late blight, Defender is also resistant to tuber early blight, PVX, and net necrosis. It has moderate levels of resistance to Verticillium wilt, pink rot, foliar early blight, corky ringspot and soft rot. Defender is susceptible to scab (common and powdery) and potato leafroll virus. It has moderate susceptibility to dry rot and PVY. Weaknesses include a relatively short tuber dormancy and susceptibility to common scab, blackspot bruise, and tuber greening. A release article for Defender was published in the American Journal of Potato Research in 2006, volume 83, p. 9-18.
The tuber type is considered long white with buff-tan skin and eyes that are intermediate in number and evenly distributed. Tuber set is low, with average size typically medium, although large tubers are common. It has relatively short tuber dormancy.