الفهرس 
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Abstract
This investigation was initiated during two consecutive seasons of 2007 and 2008 on 73 cane trained 8 years old Crimson seedless grapevines. The selected vines are visually uniform in vigour and are grown in sandy soil at 2 × 3 meters apart in a private vineyard situated at El-Tale El-Keber district, Esmailia Governorate. Vines were irrigated with drip irrigation system. In each season, the selected vines were pruned at the second week of January by using cane pruning method with Gable shape supporting system by leaving 84 eyes/vine (on the basis of 6 fruiting canes × 12 eyes + 6 renewal spurs × 2 eyes).
The scope of the present study was examining the effect of some antioxidants as possible means to improve berry setting and the yield quantatively and qualitatively of Crimson seedless grapevines. The effect of the investigated treatments on alleviating the problem of uneven colourating of berries in clusters was also concerned.
The present work included the following twenty – four treatments from four antioxidants namely ascorbic acid, citric acid, vitamins B complex (B1, B2, B6 and B12) and salicylic acid and their combinations.
Control treatment (sprayed with water).
Spraying the vines with ascorbic acid at 250 ppm.
Spraying the vines with ascorbic acid at 500 ppm.
Spraying the vines with ascorbic acid at 1000 ppm
Spraying citric acid at 250 ppm
Spraying citric acid at 500 ppm.
Spraying citric acid at 1000 ppm
Spraying vitamins B complex at 25 ppm
Spraying vitamins B complex at 50 ppm.
Spraying vitamins B complex at 100 ppm.
Spraying salicylic acid at 25 ppm.
Spraying salicylic acid at 50 ppm.
Spraying salicylic acid at 100 ppm.
Spraying ascorbic acid + citric acid each at mid. Conc.
Spraying ascorbic acid + vitamins B complex each at mid. conc.
Spraying ascorbic acid + salicylic acid each at mid. Conc.
Spraying citric acid + vitamins B each at mid. Conc.
Spraying citric acid + salicylic acid each at mid conc.
Spraying vitamins B + salicylic acid each at mid. Conc.
Spraying citric acid + ascorbic acid + vitamins B each at mid. Conc.
Spraying citric acid + ascorbic acid + salicylic acid each at mid. Conc.
Spraying citric acid + vitamins B + salicylic acid each at mid. Conc.
Spraying ascorbic acid + vitamins B + salicylic acid each at mid. Conc.
Spraying all antioxidants each at mid. Conc.
Each treatment replicated three times, one vine per each. Therefore, this experiment contained 72 Crimson seedless grapevines. The four antioxidants were sprayed four times on growth start (1st week of March), just after berry setting (2nd week of May) and at two weeks intervals (Last week of May and 2nd week of June).
For evaluating the effect of these antioxidants on growth, vine nutritional status and fruiting of Crimson seedless grapevines, the following measurements were recorded during both seasons:
Some vegetative growth characters namely main shoot length (cm.) and leaf area (cm2).
Percentages of N, P, and K in the leaves.
Percentage of berry setting.
Yield per vine expressed in weight (kg.) and number of clusters per vine .
Weight (g.), length (cm.) and width (cm.)of cluster.
Percentage of berry colouration in cluster.
Some physical characters of the berries namely weight (g.), longitudinal (cm.) and equatorial (cm.).
Some Chemical characters of the berries namely total soluble solids, total acidity and total sugars.
The nearly same obtained data in both seasons could be summarized under the following main items:-
Some vegetative growth characters:-
Single or combined application of ascorbic acid at 250 to 1000 ppm, Citric acid at 250 to 1000 ppm, Vitamins B complex (B1 + B2 + B6 + B12) at 25 to 100 ppm or Salicylic acid at 25 to 100 ppm considerably stimulated the two growth characters namely leaf area and main shoot length rather than the check treatment. The stimulation was depended on increasing concentrations. In most cases, there was a slight promotion was observed on such two growth traits among the medium and high concentrations for all the investigated antioxidants. Increasing number of antioxidants applied for the vines was accompanied with a gradual promotion on growth aspects. The maximum values were recorded on the vines received all antioxidants at the medium concentrations (500 ppm for both ascorbic and citric acids and 50 ppm for both vitamins B complex and salicylic acid). Untreating the vines produced the minimum values.
Percentages of N, P and K in the leaves.
Percentages of N, P and K were positively affected by application of the four antioxidants either singly or in combinations compared to the check treatment. The promotion was associated with increasing concentrations and number of antioxidants used. The superiority of the antioxidants in this connection was arranged as follows in ascending order, salicylic acid, vitamins B complex, citric acid and ascorbic acid. Meaningless promotion on these essential nutrients was observed among the two higher concentrations of each antioxidant. Application of all antioxidants together was very effective for maximizing these values. Leaving the vines without treatment gave the minimum values.
Percentage of berry setting:
Single or combined application of the four antioxidants namely ascorbic acid, citric acid, vitamins B and salicylic acid was very effective for improving berry setting compared to the check treatment. Increasing concentrations and number of the investigated antioxidants caused a gradual promotion on berry setting. Application of ascorbic acid, citric acid, vitamins B and salicylic acid in descending order was essential in enhancing berry setting. Application of all antioxidants together four times was responsible for maximizing this character. The minimum values were recorded on untreated vines.
Yield/ vine :
Yield expressed in weight (kg.) and number of clusters per vine was remarkably improved in response to foliar application of the four antioxidants either singly or in combinations compared to the check treatment. The promotion was associated with using ascorbic acid, citric acid, vitamin B complex, salicylic acid in, descending order. Combined application of the four antioxidants was preferable in enhancing the yield than using each antioxidant alone. The best results were obtained on the vines received four sprays of the four antioxidants each at the medium concentration, since no material promotion on the yield was observed among the higher two concentrations of each antioxidants. The lowest yield was recorded on the vines did not receive any antioxidants.
Cluster weight and dimensions :
They were positively affected with using the four antioxidants either singly or in all combinations rather than the check treatment. The promotion on cluster weight and dimensions was associated with using salicylic acid, vitamins B, citric acid and ascorbic acid, in ascending order. Increasing concentrations of the four antioxidants caused a gradual promotion on cluster weight and dimensions. No measurable effect was detected among the higher two concentrations of each antioxidant. Combined application of these antioxidants was preferable in increasing these parameters than using each antioxidant alone. Using all antioxidants together at the medium concentration materially maximized these values. The minimum values were recorded on untreated vines.
Berry Colouration % :
Single or combined application of the four antioxidants was very essential in enhancing colouration of the berries rather than the check treatment. The great advancement in colouration of the berries was occurred on the clusters picked from vines treated with ascorbic acid, citric acid, vitamins B and salicylic acid, in descending order. Spraying the vines with all antioxidants was accompanied with producing uniform colouration of clusters. The uneven cluster colouration was recorded on untreated vines.
Fruit quality :
Using the four antioxidants either singly or in all possible combinations caused an obvious promotion on fruit quality in terms of increasing berry weight and dimensions, total soluble solids and total sugars and reducing total acidity rather than non-application. Application of citric acid, ascorbic acid, vitamins B and salicylic acid, in descending order was favourable in enhancing physical and chemical characters of the fruits. Meaningless promotion on the fruit quality was recorded among the higher two concentrations of each antioxidant. Combined application was beneficial in improving fruit quality than single one. The best results with regard to fruit quality were recorded when the vines received the four antioxidants together at the medium concentration