الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The experimental work was carried out at the Experimental Farm in the Faculty of Agriculture at Moshtohor , Benha University during the two successive seasons of 2005/2006 and 2006/2007. The experiment included one item with aimed to study the effect of some growth retardants (paclobatrozol , uniconazole, and cycocel) on Tecoma stans and Cestrum elegans shrubs for feasibility of growing those genera plants as pot flowering plant production and to determine their ability to flower from seedlings at early juvenile stage.
Stem cutting of two shrubs (one year old) of each shrubs were chosen from vigorous plants and disease free and cultivated on lst September for both seasons. After five months , healthy and uniform succeeded seedlings were chosen and planted in 20 cm plastic pots filled with a 1:1:1:1 (by volume) mixture of clay , sand , peat moss and old organic manure. On
lst March the treatments were starting as follows:
1-Control (treated by distilled water)
2-Paclobutrazol at 5Oppm 3- Paclobutrazol at 100ppm 4- Paclobutrazol at 200ppm 5- Cycocel at 1000ppm
6- Cycocel at 2000ppm 7- Cycocel at 3000ppm
8- TJniconazole at 5Oppm 9- Uniconazole at 100ppm
10-Uniconazole at 200ppm
All concentrations of the three growth retardants with two shrubs were applied three times per season at 21 day
interval.
The obtained results can be summarized as follows:
V.1.Vegetative growth measurements:
V.1.A. Tecoma stans:
1-Plant height was significantly reduced due to using all growth retardant treatments in both seasons , especially PP333 at 200 ppm gave the shortest plants in both seasons.
2-Number of branches per plant was significantly reduced due to using all growth retardant treatments in both seasons , especially paclobutrozol at 200ppm gave the highest number of branches per plant in both seasons.
3-Fresh and dry weights of branches per plant was increased by control plants in both seasons. But PP333 at 200 ppm and CCC at 3000 ppm gave the least fresh and dry weights of branches/plant in both seasons.
4-Number of leaves per plant was significantly increased by using PP333 at 200 ppm in both seasons.
5-Increasing the fresh and dry weights of leaves per branch with using PP333 at 200 then with uniconazole at 100 ppm.
V.1.13 Cestrum elegans:
1-The shortest plant height resulted with. PP333 at 200 ppm. then uniconazol at 200 ppm and CCC at 3000 ppm.
2-The greatest number of branches was statistically produced with using high rate of PP333 at 200 ppm, CCC at 3000 ppm and uniconazole at 200 ppm in the first season , while in the second season CCC at 3000 ppm gave the maximum number of branches per plant, then uniconazole and PP333 at 100.
3-The least fresh and dry weights of branches per plant was obtained by PP333 at 100 ppm and CCC at 3000ppm while control plants gave the maximum fresh and dry weight of branches.
4-The highest values of number of leaves per branch were obtained by spraying cestrum plants with PP333 at 200 and 100ppm in both seasons.
5-The heaviest fresh and dry weights of leaves were obtained by PP333 at 100ppm also PP333 at 200ppm gave the next value.
V.2. Flowering measurements:
V.2.A. Tecoma stans
1- All the three used PP333 , CCC and uniconazol resulted in significant increasing the days until flowering. However, the application of PP333 at 200ppm proved to be the most effective concentration for increasing the number of days for flowering then using CCC at 3000 ppm in both seasons..
2-All the three growth retardants treatments used had enhancing effect on the number of flowers/branch in both seasons of this study. The maximum number of flowers/branch was statistically induced by PP333 at 200ppm
3- The heaviest fresh weight of flowers/branch was obtained by treating the plants with PP333 at 200ppm in the first and second seasons followed by using uniconazole at 200 ppm, while the heaviest dry weight of the flowers per branch was recorded by spraying PP333 at 200 and uniconazol at 200 ppm in both seasons.
V.2.13 Cestrum elegans:
1- PP333 at 200ppm was the most effective concentration for increasing the number of days until flowering, then using CCC at 3000 ppm in both seasons.
2-The biggest number of flowers per plant was statistically
indicated by spraying CCC at 3000ppm in both seasons, then using PP333 and uniconazol at 200 ppm.
3-The maximum fresh weight of flowers per plant was obtained by spraying the plants with PP333 at 200ppm in the first and second seasons,then with CCC at 3000 ppm. While the
heaviest dry weight of flowers per plant was recorded by CCC at 3000 ppm in both seasons.
V.3-Root measurements:
V.3.A. Tecoma scans
1-The number of roots was greatly influenced by growth retardants treatments as compared with control in both seasons. The highest number of roots per plant was recorded
with PP333 at 200 ppm, then PP333 at 100 ppm and uniconazol at 100 ppm
2-The fresh weight of roots per plant was greatly increased by using all the three growth retardants in both seasons especially PP333 at 200ppm, then using PP333 at 100 ppm followed by uniconazol at 100 ppm while the dry weight of
roots per plant was greatly increased by using PP333 at 200 ppm in both seasons.
V.3.8 Cestrum elegans:
1-Spraying the plants of estrum with PP333 at 200ppm produced the maximum number of roots per plant while
addition the treatment of CCC at 3000ppm gave the next value in both seasons.
2-The heaviest fresh and dry weights of roots per plant were obtained by spraying the high rate of PP333 (200ppm).
V-4-Chemical composition measurements:
V.4.A. Tecoma stans
1-NT’K , total carbohydrates % and total chlorophyll contents were increased in the Tecoma stans leaves when treated with PP333 at 200ppm
2-Total indoles increasing with untreated plants (control) but significant decrease by P13333 at 200ppm, CCC at 3000ppm and uniconazol at 200ppm gave the minimum total indoles
3-The greatest total phenol content was obtained by using PP333 at 200ppm and uniconazol at 200ppm in the both seasons.
V.4.13 Cestrum elegans:
1-PP333 at 200ppm (high rate) gave the maximum nitrogen, phosphorus and potassium percentages and total carbohydrates . While CCC at 3000ppm (medium rate) produced the next value . But , PP333 and uniconazol at high rate (200ppm) gave the maximum total chlorophyll.
2-Control plants gave the maximum total indoles per leaves but all the concentrations of three growth retardants showed significant decrease in leaf total indoles content of leaves in both seasons .
3-The greatest total phenol content was obtained by spraying PP333 at 200ppm. Uniconazol at 1 0Oppm gave the next value
RECOMMENDATION
*To obtain a pot flowering plants of .Tecoma stars seedlin
(five months old) from stem cutting gs
, it is recommended to
treat the plants with PP333 at 200ppm. 3 times from 13t March with 21 days interval.
* To obtain a good pot flowering plants of Cestrum elegans
seedlings ((five month old) we can safely recommend by
spraying the seedlings with PP333 at 200ppm 3 times from 1’
March with 21 days interval.