Agriculture Reference
In-Depth Information
are important in viticulture, rootknot nematodes, the citrus nematode, lesion nema-
todes and Dagger nematodes. Nematode infestation can result in a slow decline in
the productivity of the vineyard, vines can be stunted, unproductive and lacking
in vigour. Control measures largely involve using rootstocks that are tolerant to
nematode attack, although considerable research has been carried out on the use of
cover crops (companion crops) in the inter row area. A number of plants belonging
to the Cruciferaceae family (e.g. mustard, radish, canola etc) produce compounds
in their roots that can inhibit the growth of nematodes. These natural nematicides
are volatile, and so they may not remain in the soil. The technique is referred to as
biofumigation.
Rootknot nematodes include four species of
Meloidogyne
, the most important
being
M. javanica
. This nematode causes galls on grapevine roots which then be-
come stunted which impacts on root function.
Challenges and Opportunities in Viticulture
A range of challenges, but also opportunities are facing vineyard managers. Long
term climate change has the capacity to modify the fabric of an industry built on
traditions, perceptions and local education. On the other hand, the increasing mech-
anisation of vineyards and the use of precision viticulture management practices are
likely to offer further control over the component costs associated with the produc-
tion of grapes and wines for specific markets.
Climate Change
Recent global climate monitoring and modelling (AR4) indicates that anthropo-
genic climate change has the potential to increase global average temperature by
1.5-6˚ (IPCC
2007
) by 2100, with significant changes in the frequency and inten-
sity of temperature extremes. Suitable sites for viticulture would therefore shift pole
ward and in elevation (Hannah et al.
2013
; Hall and Jones
2009
; White et al.
2006
).
Global precipitation changes are less certain, although in general higher ocean and
atmospheric temperatures are likely to encourage more intense rainfall events, and
shift the distribution of rainfall. For example, strengthening of the mid-latitude high
pressure belt, linked to anthropogenic climate change, has caused reductions in
rainfall across much of southern Australian viticultural regions in recent decades
(Steffen et al.
2013
).
Significant atmospheric CO
2
enrichment should enhance biomass production
although this response varies between species and C3 and C4 photosynthetic path-
ways. Experimentation on the impacts of combined temperature/CO
2
increases
is still required to elucidate grapevine responses (Schultz and Stoll
2010
). For
improved modelling of grapevine responses to change, Global Climate Mod-
els (GCMs) need to be dynamically downscaled to resolutions more relevant to
