Key to Poplars and Willows
in New Zealand

'Toa'

• 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 light in colour with pronounced V pattern at regular intervals on the trunk, crown squat with dense dark foliage, leaves round with darker green colouring than 'Kawa', trunk broader than 'Kawa' -> 'Toa'

(Populus deltoides x P. nigra) x P. yunnanensis NZ 5007

‘Toa’ is a NZ-bred PVR-licensed tree that was first released commercially in 1996. It originates from a 1982 cross between a P. x euramericana hybrid and the Chinese balsam poplar P. yunnanensis.

Identification

‘Toa’ leaves are round with a straight to shallowly heart-shaped leaf base. The leaves are dark green on the upper surface and grey-green below, with a pink tinge on the midrib. Similar to ‘Kawa’, the leaves remain on the tree until early winter, much longer than the P. x euramericana hybrids due to the P. yunnanensis parentage.

‘Toa’ has a narrow-medium sized crown, and is heavier in the trunk than ‘Kawa’. ‘Toa’ is female.

Typical uses, site requirements, pest and disease resistance

‘Toa’ is suited to moist and fertile sites, even more so than the variety ‘Kawa’, however it will withstand some wind. ‘Toa’ is recommended for soil conservation in wet sheltered valley systems.

‘Toa’ is typically rust resistant, and the balsam parentage confers good possum resistance.

Performance in trials

At a Fan Nelder trial on a moist but exposed site in Manawatu (ann. rainfall 1200 mm), age 7 ‘Toa’ had an average height of 10.2 m and diameter (dbh) of 17 cm for trees spaced at 4 - 11 m apart. However this trial had been badly damaged by stock.

At a spacing trial near Wairoa (ann. rainfall 1250 mm), age 9 ‘Toa’ had an average height of 17.8 m, and a dbh of 34 cm for trees spaced from 5 x 5 m – 10 x 10 m.