Agriculture Reference
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Fig. 7.6  Cordon trained 10 years old Riesling vine in the process of spur pruning to two bud spurs.
Spurs are numbered to help visualise the process. From left to right, spurs 3, 4 and 5 were reduced
from two canes to one cane, itself reduced to 2 buds. The lower cane is retained in order to control
the excessive growth of the permanent spur over time
distribution within the canopy (in order to optimise carbohydrate production; pro-
mote colour development and promote fruitfulness) as well as air flow within the
canopy to reduce the severity of diseases and facilitate spray deposits. The desired
overall canopy shape, and in particular the permanent parts of the architecture is
referred to as “training”. In mechanised areas, the shape of the canopy is limited
by its compatibility with machine operations, and in particular (but not limited to)
machine harvest.
Pruning is required annually for most training systems and is greatly reduced in
vines grown in a mature “minimum pruning” system. Pruning is the action of re-
moving unwanted woody material to prepare the vine for the onset of the vegetative
growth of the subsequent year (Fig. 7.5 ). Pruning activities may range from hand
pruning to totally mechanised hedge pruning. It is an important component cost in
vineyard budgets and can occur over several months on large vineyards (Fig. 7.6 ).
Clearly, pruning is an important aspect of yield control. The number of buds left
behind after pruning represents a permanent constrain on yield formation in a given
year. For example, a 3 m row spaced vineyard, pruned at 15 buds per metres, with
a historical fruitfulness of 1.8 bunch per shoot and historical fruit weight at 120 g
per bunch will theoretically yield a maximum of 10.8 t per ha. Interestingly, yield
components such as bunch and berry characteristics will have adaptive behaviour
if the canopy architecture is modified from 1 year to another or even during a given
season. As a result a change in bunch weight in the example above (after a par-
ticularly heavy or light pruning) may lead to a different yield. Similar, a change in
bunch primordia initiation due to a departure from a canopy management practice
may lead to a change in bud fruitfulness 2 years later.
The Ideal Canopy
Smart (Smart and Robinson 1998 ) characterised canopies to create the “Winegrape
canopy ideotype”. The score card clearly demonstrates the need to grow enough
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