Abstract: This investigation was
carried out at the Experimental
orchard, Faculty of Agriculture,
Assiut University, Egypt, to
study the effect of CPPU
spraying and pinching on cluster
and berry traits of Roomy Red, as
well as, effect of berry thinning
and GA3 application on cluster
and berry traits of Ruby Seedless
grapes during 2007 and 2008
seasons. The experiment was set
up as complete randomized block
(CRB) with four replicates, one
vine per each. Pinching of both
shoots and flower clusters as well
as brushing and spraying
solutions were performed at full
bloom. The obtained results
could be summarized as follow.
GA3 at 1.5 or 3.0 ppm
spraying, brushing flowers
cluster or 1% Urea vine foliage
spraying at full bloom
significantly decreased the
berries number, weight and
compactness coefficient of
clusters compared to untreated
one.
All berry thinning reduced the
berries number and increased the
length of clusters, hence induce a
pronounced decrease in
compactness coefficient and
produced losse clusters.
GA3 at 1.5 to 3.0 ppm and
Urea at 1% spraying and
brushing the flowers cluster at
full bloom significantly increased
the berry weight, total soluble
solids, reducing Sugars and
anthocyanin in berry skin
compared to untreated ones
On the other hand, CPPU
spraying of shoots and flower
clusters at full bloom
significantly increased the berries
number, weight and compactness
coefficient of clusters compared
to untreated ones. CPPU spraying
at full bloom gave the highest
there cluster traits compared to
pinching ones.
CPPU spraying and pinching
either shoots or flower clusters at
full bloom significantly increased
the berry weight and improved
the chemical constituents of juice
and skin anthocyanin of berries
compared to untreated ones.
It could be concluded that, the
best methods for berries thinning
of Ruby Seedless grapevines that
whether GA3 at low
concentration, 1.5-3 ppm or
brushing the flower cluster at full
bloom to overcome the adverse
effects of GA3 at high
concentration. Furthermore, to
overcome the unfavorable
phenomenon's of Roomy Red
grapevine clusters, must using
either CPPU 2.5 to 5.0 ppm
spraying or pinching the shoot
tips alone or along with flower
cluster tipping at full bloom.