الفهرس 
1 . INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
was carried out during both 2009 and 2010
grown seasons on mango trees of two commercially important mango
varieties i.e., Keitte and Tommy Atkins grafted on mango seedling
rootstocks grown in a private farm located at El-Sadat region, Menoufiya
Governorate.
The
trees were 10 years-old and received the same cultural
practices in this farm.
In each variety 42 trees were selected for achieving
this study,
3 replicates for each treatment (fourteen treatments) were
arranged in a randomized complete block design. Each tree represented
one replicate.
The merit of this investigation was examining the effect of some
foliar application substances on some vegetative growth characters i.e.,
leaf chemical composition, fruit retention %, yield as well as fruit
physical and chemical characteristics of both Keitte and Tommy Atkins
mango varieties.
The trees received the following treatments:
1-
Arginine at 250 ppm.
2-
Aspartic acid at 250 ppm.
3- Glutam
ic acid at 250 ppm.
4-
Phenylalanine(2- amino -
3 phenylpropionic acid) at 250 ppm.
5- Gibberellic acid (GA3
) at 25 ppm.
6-
Naphthalen acetic acid (NAA) at 100 ppm.
7-
Amcotone (commercial mixture of 1-
naphthyl acetamide 1.2% and 1-
naphthyl acetic acid 0.
45% manufactured by Amvac, USA) at 500
ppm.
8-
Putrescine (1, 4 diamino butane) at 500 ppm.
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9- Spermidine (N-
[3-
amino propyl] butane 1, 4 diamine) at 500 ppm.
10-
Ascorbic acid at 500 ppm.
11-
Citric acid at 500 ppm.
12-
Yeast at 5000 ppm (5 g/L active dry yeast).
13-
Sea Algae extract at 2%.
14- Control treatment (sprayed with water containing Triton B
at 0.1%
which added to the spray solution as a wetting agent).
Selected trees were sprayed three times at the beginning of Spring
during growth flush (first week of February); at full bloom (first week of
April) and at just after fruit setting (third week of May). Another
agricultural practices such as irrigation, hoeing, pruning as well as pest
and fungi management were done as usual.
The following measurements were recorded during the two seasons:
1- Shoot length (cm)
2- Number of leaves per shoot
3- Leaf area in the spring growth cycle (cm2)
4- Total foliage area per shoot (cm2)
5- Percentages of N, P and K in the leaves
6- Photo pigments namely chlorophyll A and B (m
g/100 g FW) in the
fresh leaves
7- Total free amino acid content of leaf
8- The percentages of malformation
9- The length of both malformed and healthy inflorescences
10- Percentage of sex ratio
11- Fruit set; fruitlet abscission; fruit retention and number of fruits per
tree
12- Yield/tree (kg)
13- Average fruit weight (g) and volume (cm3)
14- Fruit dimensions (length and width) and shape index (length/ width)
15- Percentages of pulp, peels and seeds
16- Fruit firmness (Ib/inch2)
17- Percentage of soluble solids content (SSC)
18- Percentage of titratable acidity
19- SSC/Acid ratio
20- Ascorbic acid content (m
g/100 g pulp)
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21- Percentage of total sugars
22- Total free amino acids content of fruit
The obtained results during the two seasons could be
summarized as follows:
1-Vegetative growth:
1- The four evaluated growth measurements (Shoot length, No. of leaves,
leaf area and total foliage area per shoot) of Keitte and Tommy Atkins
mango trees followed to great extent the same trend of response during
both seasons. Herein, all foliar application substances used exceeded
statistically the control treatment. GA3 and Putrescine had the
significantly highest values and did not significantly differ from
Amcotone, Arginine, Glutamic acid, NAA and Yeast.
2- The opposite trend was observed with Citric acid where it gave the
significantly lowest values and there were insignificantly differed when
compared with other remaining treatments including the control.
2- Floral characteristics:
1- The lowest percentages of malformation were presented in the trees
treated with Gibberellic acid, Naphthalene acetic acid, Amcotone,
Putrescine or Spermidine, respectively. Similar results were obtained in
both seasons for both Keitte and Tommy Atkins varieties.
2- Present results confirmed the concept that the phenomenon of
malformation decreases the length of inflorescences. It was found that for
all treated and untreated trees, the healthy inflorescences were always
longer than the malformed ones and this statement applies for both Keitte
and Tommy Atkins varieties during the two seasons of study. GA3 gave
the highly significantly increased in length of both healthy and
malformed inflorescence followed by Putrescine and Amcotone in
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descending order. On the contrary, the control trees showed the least
value of the length of both healthy and malformed inflorescences.
3- Sex ratio was observed to be highest in flowers that appeared in
panicles of control trees, while the lowest value was observed in flowers
of panicles that appeared in foliar GA3 application. Sex ratio in flowers
that appeared in panicles of other treatments came in between. These
results were true during the two seasons in both healthy and malformed
inflorescences for both Keitte and Tommy Atkins varieties.
3- Leaf chemical composition:
1- Putrescine and Glutamic acid treatments were the superior for raising
leaf chlorophyll A and B content for both Keitte and Tommy Atkins
mango varieties during both seasons. The least values of leaf chlorophyll
A and B content were observed in control trees.
2- Putrescine and Glutamic acid increased significantly leaf N, P and K
contents in the leaves of Keitte and Tommy Atkins mango varieties
during 2009 and 2010 seasons. On the other hand the lowest percentages
of N, P and K in the leaves were observed in the untreated trees.
3- All treatments increased significantly leaf content of total amino acids
than that of untreated trees. The data for Keitte variety in both seasons
showed that Glutamic acid significantly affected by treatments tested.
4- Fruit set percentage:
1- The maximum values of fruit set percentage were detected on the trees
sprayed with Putrescine and Amcotone for both Keitte and Tommy
Atkins mango varieties during the two seasons of study, the minimum
percentage of fruit set was recorded on the control trees.
5- The percentage of fruitlet abscission:
1- Fruitlet abscission significantly affected by foliar application
treatments used. As for Keitte cv. Treated with Putrescine was the most
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effective, by exhibit
ing the minimum fruitlet abscission (98.24 and
98.37%) compared to control (98.77 and 98.96%) in the two seasons,
respectively. Also, Tommy Atkins cv. Sprayed with Putrescine had the
significantly lowest value (97.88 and 98.01%) and it did not significantly
di
ffer Amcotone (97.94 and 98.08%) and Spermidine (98.02 and 98.13%)
in the two seasons, respectively.
6- Fruit retention and number of fruits per tree:
1- Fruit retention and number of fruits per tree took a similar trend where
polyamines (Putrescine & Spermidine) and Amcotone were significantly
increased fruit retention and number of fruits compared to control
treatment. Putrescine was better than Amcotone and Spermidine, similar
results were recorded for both Keitte and Tommy Atkins varieties during
the two seasons of study.
7- Yield per tree:
1- All treatments increased significantly the yield of both Keitte and
Tommy Atkins varieties during the two seasons of study than those of
untreated ones. Putrescince treatment was more effective in increasing
tree yield as compared to other treatments. On the contrary, the least
value of tree yield was closely linked with control trees. However, tree
yield of other investigated foliar substances treatments came in between
the aforesaid two extremes.
8- Fruit physical proparties:
1- Putrescine treatment had the significantly highest value of fruit weight
and size compared to other different treatments for both Keitte and
Tommy Atkins varieties during the two seasons.
2- Fruit dimensions (length and width) showed similar trend like that of
fruit size. Nevertheless, both fruit dimensions (length & width) and fruit
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index, data obtained during both seasons displayed that the former one
(width) followed to some extent the some trend previously detected with
fruit length, while the later one (fruit shape index) had specific trend
regarding the response to various foliar application substances. The
variances in rates of response of two fruit dimensions (length & width) to
a given Putrescine treatment directly reflected on the absence of firmer
trend representing the response of fruit shape index.
3- In Keitte mango variety, the percentage of fruit peels was not
significantly affected by treatment tested herein in both seasons.
Naphthalene acetic acid treatment and Sea Algae treatment had the
significantly highest value (10.93 and 10.84%). In the first and second
seasons, respectively while Citric acid and Glutamic acid treatments had
the lowest value (10.44 and 10.32%) during first and second seasons,
respectively. In Tommy Atkins mango variety, Yeast and Sea Algae
treatments had significatly highest value, in both seasons while control
recorded the lowest value (11.0 and 11.15%) in the first and second
seasons, respectively.
4- As for percentage of fruit seed, for Keitte mango variety, in the first
seasons Yeast treatment had the signification highest value (7.82%) while
control as well as Citric acid treatments had the lowest values (7.36 and
7.38%) respectively. On the contrary, percentage of fruit seed weight in
the scorned seasons was signification affected by foliar application tested.
NAA treatment had the significantly highest value (7.64%) while control
treatment recorded the lowest value (7.20%). As for Tommy Atkins
mango variety, the trend of fruit seed was not clear in both seasons. The
results in the first seasons showed that, Phenylalanine treatment had the
significantly highest value (8.45%) and it did not significantly differ from
Ascorbic acid (8.93%), Citric acid (8.90%) and Aspartic acid (8.89%).
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The opposite trend was observed with Glutamic acid where it gave the
significantly lowest value (8.43%) and the difference were insignificant
differences when compared with other remaining treatments including the
control. In the second season, foliar applications used caused a
significantly influence on percentage of fruit seed. Ascorbic acid
treatment gave the highest significantly value (9.0%). On the contrary,
Glutamic acid treatment had the lowest significantly value (8.59%).
5- In both seasons for both Keitte and Tommy Atkins varieties, foliar
application substances used coursed significantly influence on percentage
of fruit pulp. As for Keitte mango variety, in the first seasons, Citric acid
treatment gave the highest significantly value (82.17%), while in the
second season, Glutamic acid treatment gave the highest significantly
value (82.24%) and it did not significantly differ from Putrescine
(82.17%) and Spermidine (82.16%) treatments. On the contrary, NAA
and Sea Algae treatments had the lowest significantly va
lue (81.27 and
81.57%) in the first and second seasons, respectively. As for Tommy
Atkins mango variety in both seasons, foliar application substances used
caused a significant influence on percentage of fruit pulp. In the first
season, control treatment g
ave highest significantly value (80.35%) and it
did not significantly differ from Glutamic acid (80.21%) and Putrescine
(80.05%) treatments. In the second season, Glutamic acid treatment gave
the highest significantly value (80.16%) and it did not significantly differ
from control (80.05%), Arginine (79.77%), Phenylalanine (79.75%) and
Putrescine (79.68%) treatments. On the contrary, Yeast and Sea Algae
treatments had the lowest significantly value in both seasons of study.
6- Polyamines (Putrescine and Spermidine) treatments gave the highest
significantly fruit firmness and it did not significantly differ from
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Arginine, Glutamic acid, GA3 and Amcotone treatments. On the contrary,
Citric acid treatment had the least significantly fruit firmness.
9- Fruit chemical properties:
1- All treatments significantly were preferable than the control in
improving fruit chemical characteristics of the fruits in terms of
increasing percentages of SSC, SSC/acidity ratio, total sugars, vitamin C
content and total free amino acids content but decreasing preceding of
total acidity. These results were nearly the same during the two seasons
for both Keitte and Tommy Atkins mango varieties.
2- The best results with regard to quality of the fruit were obtained with
spraying the tre
es with Putrescine at 500 ppm. The application of
polyamines (Putrescine and Spermidine) significantly induced the SSC/
acid ratio, but they decreased acidity. The higher SSC/ acid ratio in
polyamines treated fruit is due to the relatively lower acidity values
compared to the control.
Recommendation
According to statistical analysis of obtained results in the present
work it could be recommended that the best treatments were polyamines
(Putrescine and Spermidine), Ascorbic acid and Citric acid as organic
acids and safe to human health and environment, amino acids (Arginine,
Glutamic acid, Aspartic acid and Phenylalanine) and Yeast as abiocontrol
agent.
However, it could be recommended that spraying Keitte and
Tommy Atkins mango varieties with Putrescine a
t 500 ppm three
equal doses for stimulation vegetative growth, fruit set, yield as well
as fruit quality under similar conditions of our study.