Agriculture Reference
In-Depth Information
V. vinifera
is the dominant species for wine, fresh fruit or
drying. This species is thought to originate in the Caucasus
Mountains. Of the N. American species, some are used for
juicing, some for rootstock and some interspecific hybrids
for wine or dessert usage (Jackson & Looney 1999). The
selection of sports and hybridisation has traditionally been
the only methods of breeding
V. vinifera
, but they are slow
because the grape has a long life cycle and high inbreeding
depression (Gray
et al
. 1992). Over the past decade, a wide
variety of molecular techniques have been developed to
improve the identification, breeding and the study of
genetic relationships among cultivars (Lefort & Roubelakis-
Angelakis 2000; Reisch
et al
. 2000) and the grape genome
sequencing (Jaillon
et al
. 2007) is leading to intense works
in the grape research community.
The vine has deep roots and is drought tolerant although
irrigation is necessary in some production areas. It is also
tolerant of many soil types provided they are deep and well
drained. Over-fertilisation, especially with nitrogen can
lead to too vigorous growth (which may adversely affect
wine quality). The vine and developing fruits are suscepti-
ble to a number of pests and diseases (Pearson & Goheen,
1988). Some recent concerns have emerged about salt
concentrations rising in soils of irrigated vineyards, and
their effects regarding the choice of rootstocks and fruit
quality have been studied (Walker
et al
. 2007). In Europe
and the United States, it is normal to use root stock resist-
ant against the aphid
Phylloxera vastarix
which has caused
large losses in these regions. Nematode-resistant root stock
is also recommended. Fungal diseases can dramatically
affect production. During wet weather, grey mould
(
Botrytis cinerea
), downy mildew (
Plasmopora viticola
),
anthracnose (
Elsinoë ampelina
) and phomopsis
(
Phomopsis viticola
) can be serious. Powdery mildew
(
Uncinula necator syn. Erysiphe necator
) can occur in
both wet and dry regions. Crown gall (
Agrobacterium
spp.)
is the most serious bacterial disease, and there are a num-
ber of viruses that damage the vine (Jackson & Looney
1999; Patil
et al
. 1995).
Classic texts on vine cultivation include Winkler
et al
.
(1974) and Mullins
et al
. (1992). Other textbooks include
Huglin and Schneider (1998), Jackson and Looney (1999),
Reynier (1999) and Jackson (2000).
Approximately half of the grapes are transformed into
wine. The world production of wine was about 27 MT (rep-
resenting around 36 MT of grapes) with the main producer
countries being (in order of decreasing productivity): Italy,
France, Spain, the United States, China, Argentina,
Australia, South Africa, Chile, Germany and Portugal
(FAO 2009). Of this production, about a quarter is exported.
Leading exporters were: France, Italy, Spain, Chile,
Australia, the United States, Germany, Portugal and South
Africa. Only 0.5 million MT of unfermented grape juice
was exported world-wide, with the main exporters being
Italy, the United States, France, Spain, Argentina, Germany,
South Africa and Chile (FAO 2002).
The remaining 32 MT of grapes are either table grapes or
raisins (detail unknown). World export volumes of table
grapes were in the order of 2.73 million MT with the main
exporter countries being Chile, Italy, the United States,
South Africa, Mexico, the Netherlands, Greece and Turkey
(FAO 2002).
World export volumes of raisins were in the order of 0.6
million MT. The main exporters are Turkey, Iran, the
United States, Greece, Chile and South Africa (FAO 2002).
MORPHOLOGY AND PHYSIOLOGY
Introduction
Grape berry physiology and biochemistry was last reviewed
in detail by Conde
et al
. (2007) and formerly by Ollat
et al
.
(2002). The mature grape berry is a nonclimacteric fruit
with a low rate of post-harvest physiological activity.
Grapes must therefore be harvested after they have reached
optimum levels of colour development and of important
solutes such as sugars and acids. Ripening changes occur
in a relatively dramatic fashion during the development of
the berry on the vine. These changes resemble, in a number
of respects, those seen in climacteric fruit after harvest
(see section on 'Berry development').
In the last decade, there has been considerable research on
the molecular biology of berry development and maturation
(Robinson & Davies 2000). The biochemical changes and
their control systems that underpin fruit ripening, and thus
final fruit quality are gradually being elucidated.
Fruit morphology
Grape fruit develop as clusters (bunches) with each berry
attached to the bunch stem (rachis and branches) via a
pedicel which contains vascular bundles (also known as the
cap stem). There is much variation between cultivars in
stem structure (i.e. length of parts, toughness and adherence
to berries) (Winkler
et al
. 1974). Impact or shaking of
Product statistics
World production of grapes in 2009 was estimated to be
about 68 million metric tonnes (MT). The main producer
countries were, in order of decreasing production volumes,
Italy, China, the United States, France, Spain, Turkey,
Chile, Argentina and India (FAO 2009).
