Ulmus americana 'Iowa State'

Ulmus americana 'Iowa State'
SpeciesUlmus americana
Cultivar'Iowa State'
OriginIowa State University, US

The American Elm cultivar Ulmus americana 'Iowa State' was cloned in the 1980s from a tree discovered by Professor Alexander (Sandy) McNabb of Iowa State University as the sole survivor in 40 acres (16 ha) of diseased elm at Burlington.[1]

Description[edit]

The tree is possessed of a fastigiate, thickly-branched habit, but has relatively weak branch unions owing to acute angles of attachment leading to bark inclusions.

Pests and diseases[edit]

'Iowa State' was reported in the American Horticulturist News Edition, 63(5):4, 1984, as "a natural selection from southeastern Iowa, highly resistant to Dutch elm disease when inoculated". The species as a whole is highly susceptible to Elm Yellows; it is also moderately preferred for feeding and reproduction by the adult Elm Leaf Beetle Xanthogaleruca luteola,[2] and highly preferred for feeding by the Japanese Beetle Popillia japonica [3][4] in the United States. U. americana is also the most susceptible of all the elms to verticillium wilt.[5][6]

Cultivation[edit]

The cultivar was trialed in Minneapolis.[1] One of the original plantings (1978) in the Dean Park area of Minneapolis had to be felled in 2012, 34 years later, after serious defects developed.[7]

References[edit]

  1. ^ a b Santamour, Frank S.; Bentz, Susan E. (May 1995). "Updated Checklist of Elm (Ulmus) Cultivars for use in North America". Journal of Arboriculture. 21 (3): 122–131. Retrieved 20 June 2016.
  2. ^ Miller, Fredric; Ware, George (2001-02-01). "Resistance of Temperate Chinese Elms (Ulmus spp.) to Feeding by the Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae)". Journal of Economic Entomology. 94 (1). Oxford University Press (OUP): 162–166. doi:10.1603/0022-0493-94.1.162. ISSN 0022-0493. PMID 11233108. S2CID 42980569.
  3. ^ Miller, Fredric; Ware, George; Jackson, Jennifer (2001-04-01). "Preference of Temperate Chinese Elms ( Ulmus spp.) for the Adult Japanese Beetle (Coleoptera: Scarabaeidae)". Journal of Economic Entomology. 94 (2). Oxford University Press (OUP): 445–448. doi:10.1603/0022-0493-94.2.445. ISSN 0022-0493. PMID 11332837. S2CID 7520439.
  4. ^ "Elm Leaf Beetle Survey". Archived from the original on 2011-07-19. Retrieved 17 July 2017.
  5. ^ Pegg, G. F. & Brady, B. L. (2002). Verticillium Wilts. CABI Publishing. ISBN 0-85199-529-2
  6. ^ "Elm Leaf Beetle Survey". Archived from the original on 2011-07-19. Retrieved 17 July 2017.
  7. ^ Blair, (2013). Goodbye to 'Iowa State'. Elm Archives - Trees. University of Minnesota. [1]