الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
v- SUMMARY AND CONCLUSIONS
The present study was conducted during two successive
seasons, 1983-1984 and 1984-1985 to investigate
the effect of some growth regulators foliar sprays,
applied in November, on vegetative growth, flowering,
fruiting and fruit quality of ”BaLady” mandarin trees.
The major aim was to induce a shift in vegetative growth,
flowering and fruiting activities of the Balady mandarin
trees in favor of reducing the alternate bearing habit
known to be a chronic problem facing the producers of
Balady mandarin in Egypt.
Twenty ei.qht; bearing Balady mandarin trees grown
on sour orange rootstock in a private orchard at shubra--
Bakhum, Menofia Governorate were devoted for this study.
All trees were healthy, nearly uniform in size and vigor
and selected to be at the same state of bearing at the
time of treatments (all were bearing a rather heavy
crop at the time of spray).
Foliar spray treatments were applied in November
in a compLet,e randomized design using the whole tree
as a single replicate, with four replicates for each
treatment. The!spray treatments included:
1- Control (water spray) on both Nov. 7th and 21st.
2- NAA at SOD PPm applied Nov. 7th.
3- NAAat 750 PPm applied Nov. 7th.
4- NAAat 500 PPm applied Nov. 21ll’
5- NAAat 750 PPm applied Nov. 21st.
6- SADHat 2000 PPm applied Nov. 21st.
7- CCC at 2000 PPm applied Nov. 21st.
The obtained results could be summarized as follows:
A- Vegetative growth:
1- Spring flush of growth, following the application
of spray treatments showed a significant effect of the
date of foliar spray treatment on shoot growth of the
following spring. Nov. 7th sprays with 500 or 750 PPm
NAA induced the formation of taller shoots with higher
number of leaves early during the spring flush over
the control. However, such differences disappeared
toward the end of the spring cycle. Application of NAA
at the same concentrations but later on Nov. 21st. caused
an opposite trend resulting in shorter shoots with less
number of leaves than the control that persisted until
the end of the growth cycle for both seasons of study.
2- In response to foliar spray treatments on Nov.
21st. CCC at 2000 PPm induced the most retardation of
spring oyoLe shoot growth, in both seasons of study,
followed by SADH at 2000 PPm, then NAA at 500 PPm.
(95)
However, 750 PPm NAA failed to induce the degree of
retardation showed by the lower concentration of NAA
sprays (500 PPm).
3- Seasonal changes in dry matter content of both
leaves and shoots revealed that Nov. 7th sprays with
NAA showed generally the same trend for leaf and shoot
dry mptter % as the control indicating a decrease from
June till Nov. followed by a gradual increase till March
for both seasons. However, Nov. 21st. sprays with NAA,
SADH and CCC all showed a different trend than the control
where a steady gradual increase in
matter % took place from June to
with minor interruptions.
leaf and shoot dry
the following March
4- In the untreated trees leaf nitrogen % dropped
gradually from June till August followed by a sudden
but limited rise in N level till Nov. ,followed by a
gradual decrease till March. In response to foliar spray
treatments in Nov. 21st with NAA, SADH and CCC leaf
nitrogen content differed significantly in values and
trend during the season than the control. This may be
a reflection of the shift in nitrogen consumption during
the season in different growth activities in” response
to the treatments used.
(96)
5- Leaf and shoot N % differed significantly in trend
and actual values between the control trees and those
sprayed on Nov. 21st. such differences were highly
significant for both SADH and CCC sprays but not significant
for NAA sprays on Nov. 7th. such differences may
reflect the shift in vegetative growth and/or fruiting
in response to those spray treatments.
6- Seasonal changes in leaf P and K contents in
response to early Nov. sprays with NAA were similar
to that of the control. However, in June, following
late Nov. sprays with 2000 PPm SADH, 2000 PPm CCC and
750 PPm NAA, both P and K levels in leaves were significantly
lower than those of the control. These findings
could be a reflection to the more vigorous vegetative
growth showed by the control trees, resulting in a shift
in consumption activities of these nutrients. As the
season progressed, growth regulators foliar sprays on
Nov. 21st. continued to induce a change in trend and
actual values of leaf P and K contents of Balady mandarin
trees, in the two seasons of the study, than the control
trees. Such differences were highly significant throughout
the season except those of January for P levels and
these of March for K levels.
(97)
7- Total carbohydrates content and carbohydrates
nitrogen ratio in shoots of Balady mandari.n trees was
affected by late Nov. foliar sprays with growth regulators
in June, the untreated control trees showed a significantly
higher level of shoot carbohydrates over sprayed
trees. Such higher level continued throughout the season
in both seasons of study. Vigorous spring cycle vegetative
growtQ on the control trees may have induced higher
total carbohydrates and higher C/N ratio in shoots starting
from June and continued throughout the season.
On the other hand, late Nov. foliar sprays with growth
regulators induced much limited spring cycle vegetative
growth. This condition may be responsible for the lower
total carbohydrates levels as well as lower C/N ratio
in shoots of such treated trees than the untreated
controls.
B- Flowering, fruit set and yield:
Flowering, fruit set and yield were not appreciably
affected by early Nov. foliar sprays with 500 PPm or
750 PPm NAA. However, NAA foliar sprays on Nov. 21st.
appreciably enhanced flowering and fruit set of Balady
mandarin trees in the expected off-year. 500 PPm NAA
sprays were even more promising in this respect than
the higher concentration (750 PPm). But total yield,
(98)
showed an opposite trend where 750 PPm NAA developed
higher yield per tree than the 500 PPm level.
Concerning SADH sprays at 2000 PPm on Nov. 21st
it significantly enhanced flowering, increased percentages
of fruit set and resulted in the production of higher
yield/tree whether as number of fruits or Kgs. of fruits
per tree. Generally SADH sprays surpassed all other
growth regulators in promoting higher percentages of
fruitset and yield.
spraying Balady mandarin trees on Nov. 21st. with
2000 PPm CCc significantly promoted flowering in the
expected off-year, increased percentages of fruit set
and yield over the control. Generally we may conclude
that in both seasons of study the highest yield was
born on trees sprayed on 21~. Nov. with 2000 PPm SADH . followed by 2000 PPm CCC, 750 PPm NAA and’ 500 PPm NAA
in a descending order.
Corioe rLnq the number of developing fruits remaining
on the tree after fruit-set, SADH foliar sprays at 2000
PPm in late November was the most promising treatment
in reducing fruit DROP and maintaining a higher number
of developing fruits of Balady mandarin trees in the
expected off-year. Both CCC and NAA sprays induced higher
number of remaining fruits than the control but were
less than SADH sprays in this respect.
(99)
c- Fruit quality:
Study of fruit physical characteristics in response
to NOV. foliar sprays with NAA, SADH and CCC revealed
that such regulators had reduced fruit weight and size
as compared with the control. Such effect could be
attributed to the increased number of fruits produced
on the sprayed trees. Accordingly, fruit dimensions
were also reduced under such treatments. In the mean
time, all treatments had no effect on fruit index. Late
Nov. sprays with NAA, SADH and CCC induced a reduction
in fruit juice volume below that of untreated control
trees.
Generally, fruit chemical properties were only
slightly affected by the
T.S.S. in fruit juice was
foliar spray treatments. The
decreased and juice acidity
was increased (except 2000 PPm CCC) in response to growth
regulator foliar sprays. The T.S.S./acid ratio indicated
that late Nov. NAA sprays induced the production of
late maturing fruits, while 2000 PPm CCC sprays induced
earlier maturing fruits. The ascorbic acid content in
fruit juice was singificantly increased in response to
Nov. 21st. sprays with 2000 PPm SADH, 2000 PPm CCC,
750 PPm NAA and 500 PPm NAA over the control. However,
early Nov. sprays with NAA failed to show such response.
~------~ _._ ... _._._-_._._._.-
(100)
Finally we may conclude that alternate bearing
in Balady mandarin trees could be reduced by the application
of growth requlator, foliar sprays, in late November,
on trees bearing a rather heavy crop. Specifically,
2000 PPm SADH, 2000 PPm CCC and 500 PPm NAA showed
promise in this respect. Beneficial results
tree status and a
may be
obtained only if a healthy balanced
nutritional condition could be maintained. The obtained
results also indicate the importance of proper timing
of growth regulators application in determining the
kind of response displayed by the tree according to
its physiological condition and stage of development
in relation to factors of the environment.