The present study was conducted during two successive seasons 2002 and 2003 on Mit Ghamer peach trees to investigate the effect of paclobutrazol (trade name Cultar), spraying at different concentrations (0, 250, 500, 750, 1000, 1500 ppm), three weeks after full bloom, on shoot growth, yield, maturity and fruit quality, as well as leaf characters and their NPK contents. Spraying paclobutrazol highly significant decreased shoot extension at all concentrations used. The highest concentration recorded the lowest values of shoot length during the two growing seasons. The reduced shoot growth rate in the paclobutrazol treatments before pit-hardening stage, resulted in obtaining larger fruits, with a consequent increase in yield and earlier fruit maturity. The highest yield/tree (48.33 and 45.67 kg/tree) was recorded with spraying paclobutrazol at 750ppm in the first and second seasons respectively, while the lowest yield/tree (38.33; 36.33 and 36.67; 37.33 kg/tree) was obtained with spraying paclobutrazol at 1500ppm or control treatment during the tow seasons of study, respectively. Spraying paclobutrazol at 750ppm achieved the highest values of fruit weight (127.33 and 121.67 gms); volume (123.33 and 118.33 cm³); diameter (6.39 and 6.13 cm) and red skin color (76.00 and 71.67 %), during the two seasons respectively. Moreover, spraying pacloputrazol at all concentrations used increased fruit content of anthocyanin and TSS % but reduced acidity % in fruit juice in the two seasons of study. The results also showed that, leaf area and dry weight were reduced as a result of paclobutrazol spraying, the reduction was linearly with paclobutrazol concentration. No clear effect on nitrogen leaf content was noticed, but phosphorus and potassium leaf content were decreased in paclobutrazol treatments in both seasons of study.

1. EFFECT OF PACLOBUTRAZOL ON
SHOOT GROWTH, YIELD AND
FRUIT QUALITY OF MIT
GHAMER PEACH TREES.
Prof. Dr./ Galal Ismail Eliwa
Head Of Pomology Department
Faculty Of Agriculture
Damietta University
E. mail/ geliwa2002@du.edu.eg

2. INTRODUCTION
• The principle commercial
peach cultivar grown in
Dakahlia Governorate is Mit
Ghamer.
• Trees of this cultivar were
resulted from sexual seedlings.
• producing strong vegetative
growth during fruit growth
phases .
• Trees require much pruning
and hand labor would be
considerably high.

3. INTRODUCTION
• A reduction in the competition between Shoots
and fruits growth for nutrients should result in
an improvement in fruit size and quality.
• Also, exists to control tree size and
consequently simplify management operations
such as fruit thinning and harvesting .
• Many techniques have been used in an attempt
to control vegetative growth of stone fruit,
cincturing, regulated deficit irrigation and
pruning.

4. INTRODUCTION
• However, most of these techniques
have been only partially successful in
controlling tree growth
• The growth retardant, paclobutrazol
has shown promise in ;
• controlling the growth of extension
shoots
• increased floral bud initiation ,fruit
numbers per tree and fruit size .

5. THE AIM OF THIS STUDY
• To investigate the exact concentration of
paclobutrazol which can be control
vegetative growth and improve yield and
fruit quality of Mit Ghamer peach trees.

6. MATERIALS AND METHODS
• Treatments:
• Spraying PLZ at 0 ppm (control).
• Spraying PLZ at 250 ppm.
• Spraying PLZ at 500 ppm.
• Spraying PLZ at 750 ppm.
• Spraying PLZ at 1000 ppm.
• Spraying PLZ at 1500 ppm.
• The application was at approximately
three weeks after full bloom

7. The following parameters
were determined :
• Shoot growth
• Yield and Maturity
• Fruit characteristics
–Physical fruit characteristics
–Chemical fruit characteristics
• Leaf characteristics
–Leaf area and dry weight %
–Leaf nutrients

8. RESULTS
Shoot growth

9. Effect of different concentrations of
paclobutrazol on shoot growth of peach
trees (data are the mean of 2002 and 2003 seasons).
Shoot growth (cm)
Treatmen
ts
1 Oct.
15
Sept.
1
Sept.
15
Augs
.
1
Augs
.
15
July
1 July
15
June
1
June
15
May
1
May
15
Apri
l
1
Apri
l
15
Mar
ch
68.33
57.07
48.00
48.43
42.57
38.57
67.00
56.73
47.77
48.43
42.57
38.57
67.33
55.83
47.00
48.33
42.37
38.20
65.67
54.90
46.33
48.00
42.23
37.67
64.00
57.17
45.00
47.50
41.73
36.93
63.17
52.27
44.33
47.17
41.40
36.67
61.50
52.00
43.50
46.67
40.90
36.00
59.67
51.17
43.00
45.33
40.57
35.00
57.67
47.17
41.33
43.67
40.07
33.67
55.67
45.07
40.00
42.67
38.57
32.80
51.33
44.07
39.83
40.60
36.17
30.43
46.17
39.70
36.00
36.00
31.17
27.33
36.00
33.17
28.33
29.57
25.37
23.70
17.67
17.83
17.73
15.70
15.07
14.50
Contrl
250 ppm
500 ppm
750 ppm
1000 ppm
1500 ppm
11.33
16.11
11.38
16.19
11.22
15.96
11.26
16.01
11.40
16.21
11.03
15.69
10.85
15.42
10.65
15.14
9.27
13.18
7.73
11.0
7.22
10.27
7.81
11.11
7.73
---
NS
L.S.D.at1
%
L.S.D.at5
%

10. 0
10
20
30
40
50
60
70
80
15M
ar.01-Apr15-Apr01-M
ay15-M
ay
01-Jun
15-Jun
01-Jul
15-Jul1
Aug.15
Aug.1
Sept.15
Sept.1
O
cto.
Date
Shootlength(cm)
Control
250ppm
500ppm
750ppm
1000ppm
1500ppm
Effect of paclobutrazol spray on shoot growth of
peach trees

11. Effect of spraying Paclobutrazol on
yield and precocity of peach trees
during 2002 and 2003 seasons.
First picking before
control (Days)
Yield (kg/tree)
Treatments 2003200220032002
--
3.0
5.3
5.5
5.3
2.0
--
4.3
6.0
6.0
6.3
3.3
37.33
41.00
43.67
45.67
42.00
36.33
36.67
43.33
45.00
48.33
43.33
38.33
Control
250 ppm
500 ppm
750 ppm
1000 ppm
1500 ppm
----
3.83
5.44
4.12
5.86
L.S.D. at 5%
L.S.D. at 1%

12. Effect of spraying paclobutrazol on
physical fruit characteristics of peach
trees during 2003 and 2003 seasons.
Red skin
color %
Firmness
(kg/cm2)
Fruit
length
(cm)
Fruit
diameter
(cm)
Fruit volume
(cm³)
Fruit weight
(gms)
Treatmen
ts
2003200220032002200
3
200
2
200320022003200220032002
38.33
50.00
64.00
71.67
70.67
45.67
40.67
49.33
67.33
76.00
76.00
44.67
4.09
5.00
5.27
4.37
5.37
4.97
4.49
4.78
5.27
4.38
5.51
5.08
5.53
6.13
6.02
6.02
5.67
5.82
5.63
6.09
6.02
6.20
5.89
6.03
5.47
5.77
5.93
6.13
5.67
5.88
5.69
5.90
6.03
6.39
5.79
6.07
90.67
102.33
107.67
118.33
97.67
103.00
94.67
104.67
109.33
123.33
98.67
110.00
94.33
105.33
114.00
121.67
103.33
110.67
96.67
109.33
115.33
127.33
106.67
113.33
Control
250 ppm
500 ppm
750 ppm
1000 ppm
1500 ppm
5.86
8.34
8.32
11.83
0.73
--0.75
--
NS
0.28
---
0.26
0.36
0.18
0.26
4.39
6.24
7.14
10.16
5.11
7.26
8.90
12.66
L.S.D. at
5%
L.S.D. at
1%

13. Effect of spraying Paclobutrazol on
chemical fruit characteristics of peach
trees during 2002 and 2003 seasons.
Acidity %TSS %
Anthocyanin
(optical
density)
Treatments 200320022003200220032002
1.206
1.021
1.070
1.071
0.960
0.855
1.224
0.947
1.114
1.114
0.891
0.835
10.03
11.07
10.70
11.30
12.13
10.07
10.13
11.27
10.87
11.57
12.33
10.33
0.130
0.184
0.192
0.200
0.209
0.159
0.120
0.181
0.190
0.210
0.225
0.150
Control
250 ppm
500 ppm
750 ppm
1000 ppm
1500 ppm
0.080
0.114
0.115
0.163
0.77
1.10
0.77
1.09
0.020
0.029
0.015
0.022
L.S.D. at 5%
L.S.D. at 1%

14. Effect of spraying Paclobutrazol on
peach leaf characteristics and NPK
contents during 2002 and 2003 seasons.
K%P%N%
Dry weight
%
Leaf area
(cm2)
Treatments 2003200220032002200320022003200220032002
1.97
1.88
1.87
1.87
1.87
1.75
2.19
1.91
1.88
1.88
1.86
1.70
0.23
0.20
0.20
0.19
0.19
0.18
0.24
0.21
0.20
0.19
0.19
0.18
2.29
2.31
2.17
2.17
2.30
2.30
2.26
2.32
2.18
2.17
2.29
2.29
45.20
42.70
44.17
43.77
42.96
42.67
46.27
43.76
44.78
44.28
44.24
43.35
39.29
37.92
37.29
35.11
34.76
30.56
40.57
40.29
39.33
36.73
36.04
32.95
Control
250 ppm
500 ppm
750 ppm
1000 ppm
1500 ppm
0.07
---
0.18
0.25
0.03
---
0.03
0.04
NSNS
0.41
---
0.77
---
4.10
5.83
2.05
3.56
L.S.D. at 5%
L.S.D. at 1%

15. SUMMARY
Spraying paclobutrazol highly significant
decreased shoot extension at all
concentrations were used.
 The highest concentration recorded the
lowest values of shoot length during the
two growing seasons.
The reduction in shoot growth rate before
pit-hardening stage, resulted in obtaining
larger fruits, with a consequent increase
in yield and earlier fruit maturity .

16. SUMMARY
Spraying paclobutrazol at 750ppm achieved the
highest values of yield/tree (48.33 and 45.67
kg/tree) ,fruit weight (127.33 and 121.67 gms);
volume (123.33 and 118.33 cm³); diameter (6.39
and 6.13 cm) and red skin color (76.00 and
71.67 %), during the two seasons respectively.
Moreover, spraying pacloputrazol at all
concentrations used increased fruit content of
anthocyanin and TSS % but reduced acidity %
in fruit juice in the two seasons of study.

17. SUMMARY
The results also showed that, leaf area
and dry weight were reduced as a
result of paclobutrazol spraying .
No clear effect on nitrogen leaf content
was noticed, but phosphorus and
potassium leaf content was decreased
in paclobutrazol treatments in both
seasons of study.

18. Conclusion & Recommendations
Conclusion & Recommendations
It could be concluded from this study
that spraying Mit Ghamer peach
trees with paclobutrazol at 750 ppm
was more effective in controlling
shoot growth, eliminating the need
for summer pruning, increasing
yield, advancing in fruit maturity
and improving fruit quality.

19. Bon appétit

20. Thanks for your attention!