Environmental Engineering Reference
In-Depth Information
(a)
(b)
(c)
(d)
FIGure 28.6
(a) Uredinia on an
S. cordata
×
S. eriocephala
hybrid, (b) giant willow aphid
(
Tuberolachnussalignus
) on shrub willow, (c) Japanese beetle (
P. japonica
) damage on
S. dasyclados
, and
(d) potato leaf hopper (
Empoascafabae
) damage on an
S. viminalis
×
S. miyabeana
hybrid.
broad effect on bioenergy plantation yield, but may reduce cutting yield in nursery plantations. Fungal
pathogens,
Colletotrichum
spp.,
Dothiorella
spp.,
Botryosphaeriadothidea
,
Cytospora
spp., and
Leucostoma
spp., associated with stem cankers have been identified (S. Kenaley, G. Hudler, Cornell
University, unpublished data) in biomass plantations, but these slow-growing diseases localized to the
upper portions of stems are regularly removed by harvest on a short rotation. As long as stem canker
or tip dieback diseases do not penetrate into the stool, they typically have only a minor impact because
buds just below the affected area will rapidly break dormancy and emerge to continue growing.
Leaf-feeding and stem-sucking insects can have a significant negative effect on the yield of
short-rotation coppice willow (Kendall et al. 1996; Björkman et al. 2000, 2008; Kreuger and Potter
2001; Bell et al. 2006; Björkman et al. 2008). Partial defoliation, as occurs with beetle feeding,
is the most common problem and is usually due to both generalists that can feed on a range of
hosts, such as the Japanese beetle (
Popillia japonica
Newman; Figure 28.6) and specialists that are
