Key to Poplars and Willows
in New Zealand

'Otahuao'

• 0. Poplar or Willow?
• Looks like a poplar -> Poplar - 1. Crown shape
• Narrow crown (or uncertain) -> 2. Bark
• Bark is rough -> 4. Bark and form
• Bark coarsely ribbed, ribs not parallel. Apical dominance, often with a heavy asymmetrical branch(es), leaves with green upper surface, light green lower surface, leaves hang down from stem -> 6. P. x euramericana hybrids
• Medium sized crown, occasionally heavy branches, smoother bark than other <i>P. x euramericana</i> hybrids, little rust -> 'Otahuao'

Populus deltoides x P. nigra NZ 5020

‘Otahuao’ is a P. x euramericana hybrid, resulting from a 1980 NZ cross between P. deltoides and P. nigra ‘Italica’. It was first released commercially in 1993.

Identification

‘Otahuao’ leaves have a straight base and a distinctive undulating or wrinkled leaf margin. The leaves are dark green above and light green below. As a young tree ‘Otahuao’ has smoother bark than the other P. x euramericana hybrids.

‘Otahuao’ has a medium sized crown, a heavy stem and occasionally a few heavy branches. ‘Otahuao’ is female.

Typical uses, site requirements, pest and disease resistance

‘Otahuao’ is suitable for soil conservation, particularly in eastern regions. It has good wind and drought tolerance and can be used in the lower slopes, below ‘Argyle’ and ‘Veronese’.

‘Otahuao’ is less susceptible to rust than varieties ‘Dudley’ and ‘Selwyn’ - it was the only clone that stayed rust-free in Wairarapa in 2003-04. ‘Otahuao’ is possum palatable.

Performance in trials

In a Wairarapa trial (ann. rainfall 850 mm) of 15 hybrids, ‘Otahuao’ at age 12 had an average dbh of 34 cm (c.f. Weraiti 36 cm, ‘Kawa’ 27 cm), and an average height of 16.1 m (c.f. ‘Weraiti’ 17.9 m, ‘Kawa’ 15.4 m). This resulted in the fourth highest volume index, behind ‘Weraiti’, ‘Argyle’ and ‘Margarita’. At age 12 in Manawatu (ann. rainfall 1200 mm) ‘Otahuao’ dbh averaged 27 cm, and at age 13 in Otago (ann. rainfall 600 mm), average dbh was 21 cm.