الفهرس 
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Abstract
Experiment was carried out throughout two successive seasons of 2020 and 2021on Ruby Seedless grapevines grown at the Experimental Orchard of Assiut University, Faculty of Agriculture thirty-tow uniform grapevines (8 treatments x 4replications).
Treatments:
1- Spraying Ascorbic acid (AA) at 400 ppm
2- Spraying Ascorbic acid (AA) at 600 ppm
3- Spraying Citric acid (CA) at 400 ppm
4- Spraying Citric acid (CA) at 600 ppm
5- Spraying Abscisic acid (ASA) at 400 ppm
6- Spraying Abscisic acid (ASA) at 600 ppm
7- Spraying Ascorbic acid (AA) at 600 ppm + Citric acid (CA)at 600 ppm + Abscisic acid (ABA)at 600 ppm
8- Control (untreated vines).
Yield components and cluster measurements:
Clusters per vine were collected and weighed at harvest date in both seasons to estimate yield weight (kg/vine). Three clusters were taken at random from each vine to obtain the average cluster weight, which was then used to assess the following attributes:
Cluster dimensions:
• Cluster length (cm) and cluster width (cm).
• Cluster length/width (L/W ratio).
• Cluster rachis weight (g).
Berry measurements:
• 100 berries weight (g).
• 100 berries juice weight (g)
• Berry length (cm) and berry diameter (cm).
• Berry L/D ratio
Chemical constituents:
• Total Anthocyanin’s content (mg/100 g fresh wt.).
• Total soluble solids percentage (TSS %).
• Total acidity (%) was determined by the direct titration method.
• TSS / acid ratio was then calculated.
• The reducing sugars percentage.
The obtained results can be summarized as following:
Yield components and cluster measurements:
Yield weight (kg/vine):
All treatments led to a significant increase in the yield weight.
Cluster weight (g):
Most of the treatments led to an increase in the cluster weight, and the best treatments were (T7) Ascorbic acid (AA) at 600 ppm + Citric acid (CA)at 600 ppm + Abscisic acid (ABA) at 600 ppm.
Cluster dimensions:
Cluster length (cm):
Two seasons of average data demonstrated that none of the treatments had a significant effect on this trait compared the control.
Cluster width (cm):
The treatment had no significant effect on cluster width over the control, although some treatments were higher than the control.
Cluster length/width (L/W ratio):
The cluster L/W ratio in the 1st increased significantly as a result of the treatment, with the exception of T3 (citric 400 ppm). The combined analysis over the two years of study showed that all treatments had no significant effect on this trait compared the control.
Cluster rachis weight (g):
The treatment T6 (ABA 600) significantly increased the cluster rachis weight compared with the control during the 1st season of study. As for the rest of the treatments, they had no significant effect. The results of the second season show what the results of the first season showed. Two seasons of average data demonstrated that the vines which were subjected to ABA at 600 ppm recorded the highest values. As for the rest of the treatments, they had no significant effect compared to the control.
Berry measurements:
100 berries weight (g):
In lisnt season, the vines treated with abscisic acid at(400ppm) produced the highest berry weight. The effect of the tested remainder treatments on berry weight was not significant. During the second season of studies,all treatments significantly exceeded the control. The highest values were obtained from the vines treated with Ascorbic acid at (600ppm). two seasons of average data showed that some treatments were un significant on berry weights the best treatments were T6 (Abscisic 600 ppm).
100 berries juice weight (g):
All treatments had no significant effect on this trait during the 1st season. The 2nd season results demonstrator that. The best treatments were T2. The combined analysis over the two years of study revealed that the treatments T3 and T7 had not a significant effect on Berries juice weight. most of treatments significantly exceeded the control. The most effective treatments in this respect were T2.
Berry dimension:
Berry length (L) (cm):
The majority of treatments had no significant effect on berry length in the 1st season. The treatment T4 (citric 600 ppm) significantly increased the yield compared with the control. During the 2nd season, the treatment T3(critic 400) achieved the highest value and had a significant effect. As for the rest of the treatments, they had no significant effect compared to the control. The analysis over the two years of study showed that most treatments had no significant effect on this trait over the control. The treatment T3 (critic 400) achieved the highest value and had a significant effect.
Berry diameter (D) (cm):
All the treatments had not significantly increased the berry diameter compared with the control in the 1st season. During the 2nd season, the treatment T1 (ascorbic 400 ppm) achieved the highest value and had a significant effect. most treatments had not a significant effect on this trait over the control. Two seasons’ average data demonstrated that most treatments had not a significant effect on this trait over the control. The vines which were subjected to ascorbic at 400 ppm (T1) recorded the highest values.
Berry L/D ratio:
No significant differences between the treatments on berry length/ diameter ratio in the 1st season. During the 2nd season, most of the treatments did not significantly exceed the control. The highest ratios were taken from treatment T3 (citric 400). It is the treatment that achieved a significant increase only. Two seasons average data show that the treatments had no a significantly exceeded the control. The highest ratios were taken from treatment T3 (citric 400).
Chemical constituents:
-Total soluble solids percentage (TSS %):
The results showed that most of the treatments did not have any significant effect compared to the control. Treatment (citric 400ppm) gave the highest results.
-Total acidity percentage:
During the two seasons of study, all tested treatments significantly decreased total acidity compared to the control, with no significant differences between them. Two seasons of average data demonstrated that abscisic 600 ppm gave the least value.
-Total soluble solids/acid ratio:
The treatments significantly increased the in the total soluble solids/ total acidity ratio1st,2nd and Two seasons average of study. During the ”1” season, the best treatment in that respect was T3 (citric400ppm). The 2nd season results demonstrate that the best treatments were T1. The combined analysis over the two years of study revealed that all the treatments exceeded the control. The best treatments in this respect were T3.
-Reducing sugars percentage:
During the ”1” season most of the treatments significantly increased the Reducing sugars with the exception of T4, T6 and T7. The 2nd season showed that the all treatments significantly increased the reducing sugars. that the best treatments were T7 and T6. Two seasons of average data showed that most of the treatments significantly increased the Reducing sugars with the exception of T4. The best treatments in this respect were T3, followed by T5.
-Total Anthocyanins content of Ruby Seedless grapes:
All the treatments significantly exceeded the control Especially treatments that contain ABS the 1st and 2nd seasons of stud. The treatment ascorbic 600ppm +citric 600ppm +abscisic 600 ppm gave the best results.
Conclusion and recommendation:
On the light of obtained results of this study, it could be concluded that the best treatments were citric acid (400 ppm) and Ascorbic acid (600 ppm) + Citric acid (600 ppm + Abscsic acid (600ppm).