IMPACT OF SUSTAINED DEFFICIT IRRIGATION AND FOLIAR SPRAY OF ASCORBIC ACID ON PRODUCTIVITY AND PEEL DISORDERS OF WONDERFUL POMEGRANATE TREES

The investigation was carried out during 2017and 2018 seasons on Wonderful pomegranate trees grown at private orchard located on Cairo-Alexandria Desert road about 50 Km from Cairo, Egypt. Trees planted at 3x5 meters apart in sandy soil and watered from wells using drip irrigation system. The trial was a factorial experiment, hence sustained deficit irrigation100%, 80% and 60% from crop evapotranspiration (ETc) throughout season, the occupied main plot, whereas foliar sprays of ascorbic acid treatments at 0, 500, 750 and 1000 ppm /tree located in the subplots were carried out two times, the first foliar spray was done at full bloom and the second one was performed four weeks later. The results showed that leaf characteristics (leaf area and total chlorophyll), number of fruits per tree, yield and fruit quality traits (weigh, length, diameter, weight of fruit grains, flesh percentage, weight of 100 grains and juice volume) recorded the highest values with higher both irrigation level and sprays of ascorbic acid treatments. On the contrary fruits cracked percentage and fruits sunburned percentage, peel thickness, total sugar, TSS, TSS/acidity, ascorbic acid and water used efficiency showed an adverse correlation with irrigation level. Also, spraying by ascorbic acid is reducing number of fruit cracked, number of sunburned fruits and acidity. On other hand, peel thickness, total sugar, TSS, TSS/acidity and ascorbic acid concentration were increasing. Therefore, sustained deficit irrigation is considered to be an effective strategy for arid and semi-arid regions, moreover ascorbic acid may be used to prevent or mitigate oxidative damage caused by sustained deficit irrigation.

The investigation was carried out during 2017and 2018 seasons on Wonderful pomegranate trees grown at private orchard located on "Cairo-Alexandria Desert" road about 50 Km from Cairo, Egypt. Trees planted at 3x5 meters apart in sandy soil and watered from wells using drip irrigation system. The trial was a factorial experiment, hence sustained deficit irrigation100%, 80% and 60% from crop evapotranspiration (ETc) throughout season, the occupied main plot, whereas foliar sprays of ascorbic acid treatments at 0, 500, 750 and 1000 ppm /tree located in the subplots were carried out two times, the first foliar spray was done at full bloom and the second one was performed four weeks later. The results showed that leaf characteristics (leaf area and total chlorophyll), number of fruits per tree, yield and fruit quality traits (weigh, length, diameter, weight of fruit grains, flesh percentage, weight of 100 grains and juice volume) recorded the highest values with higher both irrigation level and sprays of ascorbic acid treatments. On the contrary fruits cracked percentage and fruits sunburned percentage, peel thickness, total sugar, TSS, TSS/acidity, ascorbic acid and water used efficiency showed an adverse correlation with irrigation level. Also, spraying by ascorbic acid is reducing number of fruit cracked, number of sunburned fruits and acidity. On other hand, peel thickness, total sugar, TSS, TSS/acidity and ascorbic acid concentration were increasing. Therefore, sustained deficit irrigation is considered to be an effective strategy for arid and semi-arid regions, moreover ascorbic acid may be used to prevent or mitigate oxidative damage caused by sustained deficit irrigation.
Water scarcity is become the one of the main factors limiting agricultural development in Egypt. And agriculture activity will suffer from water shortage currently and in the future irrigation. In addition, irrigation water is limited in most new reclaimed regions. Water scarcity has become a challenge for agricultural production. In this case, ISSN: 2320-5407 Int. J. Adv. Res. 8

(09), 1043-1058
1044 deficit irrigation is an ideal water saving technique when applied on many fruit orchards. Deficit irrigation has been widely investigated as a valuable strategy under water scarcity (Pereira et al., 2002), reducing agricultural water use (Fereres and Soriano, 2007), for dry region (English, 1990 andFereres et al., 2003). Deficit irrigation mean the water is applied at rate less than the need of crop evapotranspiration (ETc). The adoption of deficit irrigation by farmers is one of the options that can help to save irrigation water under desert conditions. In irrigated fruit trees, deficit irrigation strategy has been proposed to save water without major effects on yield (Chalmers et al., 1981). Deficit irrigation caused a significant decrease in crop yield compared to full irrigation (Tavousi et al., 2015). Intrigliolo et al. (2012) showed that deficit irrigated treatments allowed increasing water use efficiency. Ghanbarpour et al. (2018) indicated that fruit cracking in the pomegranate cultivar dependent on irrigation. Fruit cracking is a serious problem in pomegranate orchard as it causes about 50% of fruit marketing value (El-Masry, 1995). Vegetative growth and fruits quality were significantly affected by levels of soil moisture of field capacity (Abdel-Sattar and Mohamed, 2017). Water deficit stress induces numerous biochemical and physiological responses in plants ( Pattangual and Madore, 1999). Zahedi and Moghadam (2011) reported that antioxidant enzymes activity was increased when plants were exposed to water deficit. Under conditions of water deficit, reactive oxygen species (ROS), such as superoxide anion radicals, hydrogen peroxide and hydroxyl radicals, are generated (Zhu, 2000). Plant cells contain an array of protection mechanisms and repair systems that can minimize the occurrence of oxidative damage caused by reactive oxygen species (Abdel Latef, 2010). To prevent or mitigate oxidative damage from ROS, plant cells possess a enzymatic antioxidant system that includes tocopherols and ascorbic acid.
Antioxidants such as ascorbic acids are safe to human and environment (Elade, 1992). It has also been reported that application of exogenous ascorbic can reduce oxidative stresses (Shalata and Neumann, 2001). It is considered as an antioxidant and association with other components of the antioxidant system. It protects plants against oxidative damage (Smirnoff, 1996). Ascorbic has been shown to play multiple roles in plant growth, such as in cell division, cell wall expansion and other developmental processes (Lee andKader, 2000 &Pignocchi andFoyer, 2003). Moreover, ascorbic acid functions as enzymatic cofactor, and it plays important roles in many physiological processes, including photosynthesis, photo-protection, stress resistance, biosynthesis of hormones and cell wall constituents (Davey et al., 2000 &Barth, 2004). Ascorbic acid has auxinic action. It has a synergistic effect on improving growth, flowering, yield and fruit quality of fruit crops (Barth et al., 2006). Abd-El-Rhman et al. (2017) reported that foliar spray ascorbic acid enhanced yield and fruit quality of Manfaloty pomegranate trees. Atef (2018) pointed out that foliar spray ascorbic acid improved growth, yield fruit quality of Wonderful pomegranate trees.
The aim of this study is to investigate the effect of foliar ascorbic acid under sustained deficit irrigation on vegetative growth, yield and fruit quality as well as water used efficiency of Wonderful pomegranate trees.

Material and Methods:-
This investigation was carried out during two successive seasons 2017 and 2018 at orchard located on "Cairo-Alexandria desert" road about 50 km from Cairo (latitude 30°9′ 2.92″ N, longitude 30°40′ 31.75″ E at an elevation of 200 m above sea level), Egypt. Wonderful pomegranate trees (Punica granatum L.) aged 7 years old grown in sandy soil, and spaced 3 x 5 m apart (280 trees / fed) under drip irrigation system from well. Physical and chemical analysis of the experimental soil shown in Table 1, meanwhile the chemical analysis of used water from irrigation is recorded in (Table 2).
This experiment was considered a Factorial design, the sustained deficit irrigation (SDI) (60%, 80% and 100% of ETc) being the first factor and ascorbic acid (AsA) foliar sprays (0, 500, 750 and 1000 ppm) the second factor, with three replicates for each treatment and each replicate was represented by two plants.  (3) C = ¾ ×π×ɑ×b 2 (4) When (a) is of canopy height (m), and (b) is half of canopy spread (m) according to Westwood (1993) The four treatments regarding ascorbic acid spraying were: control tap water, , ascorbic acid as foliar sprays at 500 ppm, ascorbic acid as foliar sprays at 750 ppm, ascorbic acid as foliar sprays at 1000 ppm. Were carried out two times, the first foliar spray was done at full bloom and the second one was performed four weeks later, in both seasons. Tween-20 was added at 0.1% as a surfactant to spray solution including the control "tap water". Spraying was carried out using compression sprayers (5L solution per tree) at the previously mentioned dates. This study is considered a factorial experiment hence a split plot is devoted to the sustained deficit Irrigation as main plot whereas ascorbic acid foliar occupied sub-plot. The element of each factor was replicated three times.
Seventy two healthy trees, nearly uniform in shape, size, and productivity received the same horticulture practices were subjected to the tested sustained deficit irrigation and ascorbic acid treatments and evaluated through the following determinations.

Leaf characteristics
The area of leaves was determined by using portable area planimeter Mod Li3100 Ali (Li-Cor) while Leaf total chlorophyll content was determined by Minolta chlorophyll meter SPAD-502.

Number of fruits/tree and yield kg/tree
At harvest time, the number of fruits per each treated tree was counted and reported then yield (kg) per tree was weighed and recorded Cracked and sunburned fruits Number of cracked and sunburned fruits per tree was counted and recorded.

1046
Fruit physical and chemical properties Ten fruits were taken at harvest from each treated tree for determination of the following physical and chemical properties. Fruit weight (g), fruit length (cm), fruit diameter (cm), weight of fruit grains (g), flesh (%), weight of 100 grains (g), juice volume (cm 3 ) per fruit, peel thickness. Furthermore, total sugar (%), total soluble solids (T.S.S.) was determined by Hand refractometer, total acidity in fruit juice (expressed as citric acid per 100 ml juice), TSS/ Acid ratio and ascorbic acid (mg ascorbic acid/100 ml juice) according to A.O.A.C. (1995).

Statistical analysis
The obtained data in 2017 and 2018 seasons were statistically analyzed by MSTAT-C soft-ware and means were differentiated using Rang test at the 0.05 level (Duncan, 1955).

Leaf characteristics Leaf area (cm 2 )
Table, 3 illustrate that significant differences were noticed between the tested irrigation levels. However, under sustained deficit irrigation treatments level 100% irrigation resulted the highest increment in the leaf area value followed descending by 80% and 60% irrigation treatment in both two seasons, respectively.
Moreover, spraying treatments of ascorbic acid increased leaf area as compared with the control in both seasons of study; the highest leaf area was recorded with ascorbic acid foliar spray at 1000 ppm treatment followed ascorbic acid at 750 ppm treatment and ascorbic acid at 500 ppm and control (tap water), respectively.
However, the interaction between the two tested factors showed that irrigation at 100%support with ascorbic acid foliar spray at 1000 ppm recorded the highest value on the leaf area value (5.56 and 5.45 cm 2 ) followed descending by ascorbic acid foliar spray at 750 ppm (5.28 and 5.05cm 2 ) ascorbic acid foliar spray at 500 ppm treatment (4.76 and 4.58 cm 2 ) and control (tap water) (4.23 and 3.93 cm 2 ) in both two seasons, respectively. The same trend noticed with other levels irrigation 80% or 60%. In the other side, irrigation treatment at 100% combined with spraying ascorbic acid at 1000 ppm proved to be the best interaction in this regard. Table, 3 shows that 100% level of irrigation gave the highest value of total chlorophyll followed by 80% in descending order. Meanwhile, the lowest total chlorophyll value was recorded with 60% irrigation in both seasons.

Leaf total chlorophyll content
In addition, the highest total chlorophyll value was recorded with 1000 ppm ascorbic acid while control treatment recorded the lowest values in this respect. Moreover, no significant differences were noticed between ascorbic acid treatments at 750 and 500 ppm.
Irrigation levels with spray treatments showed that irrigation at 80% with ascorbic acid foliar spray at 1000 ppm gave high value in total chlorophyll (57.36, and 58.16) followed descending by ascorbic acid foliar spray at 750 ppm (54.47, and 55.20) ascorbic acid foliar spray at 500 ppm treatment (53.33and 52.93) and control (tap water) (47.66 and 47.67) in both two seasons, respectively in this regard. The same trend noticed with other levels irrigation 100% or 60%.
The combined effects of irrigation levels with spray treatments showed that 100% irrigation level with ascorbic acid at 1000 ppm was the most effective treatment in increasing total chlorophyll, finally irrigation level at 60% combined with control treatment resulted in less effective in total chlorophyll.
1047 The enhancement effect of ascorbic acid on leaf characters may be attributed that ascorbic acid has positive action in catching all free radicals produced during plant metabolism (Alscher et al., 1997). Moreover, ascorbic acid has an auxinic action and synergistic effect on tree growth (Ragab, 2002). Ascorbic acid may serve as a potential growth regulator to enhance stress resistance in several species (Shalata andPeter, 2001 andKhan, 2006). Foliar application of ascorbic acid increased in photosynthesis (Tarraf et al., 1999). The obtained results regarding the effect of ascorbic acid on leaf characteristics go in line with the findings of El-Sayed et al. (2014) mentioned that ascorbic acid treatments enhanced leaf area and total chlorophyll of Manzanillo olive trees. Atef (2018) showed that foliar sprays with ascorbic acid enhanced growth parameters of "Wonderful" pomegranate trees.
No. of fruits/tree and yield kg/tree No. of fruits/ tree Table, 4 indicates that irrigation level at 100% recorded the highest number of fruits per tree followed irrigation level at 80% and irrigation level at 60%, respectively in both seasons.
Furthermore ascorbic acid 1000 ppm treatment gave the highest increment in number of fruits per tree followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm and control treatment.
Meanwhile, the interaction between irrigation and spraying treatments revealed that the highest number of fruits per tree value was recorded with irrigation level at 100% combined with spraying ascorbic acid at 1000 ppm. On the contrary, the combination between 60% irrigation level and tab water foliar spray gave the least positive effect on increment on the number of fruits per tree. Irrigation level at 60% with spray treatments ascorbic acid at 1000 ppm proved to be effective interaction in increasing number of fruits per tree (69.83and 67.83) followed descending by ascorbic acid foliar spray at 750 ppm (65.0 and 57.66) ascorbic acid foliar spray at 500 ppm treatment (57.5 and 52.16) and control (tap water) (52.0 and 46.33) in both two seasons, respectively in this respect. The same trend noticed with other levels irrigation 100% or 80%. Means followed by the same letter (s) within each row, column or interaction are not significantly different at 5% level.

Yield (Kg) / tree
It is clear from Table, 4 that significant differences on tree yield were resulted negatively by reducing irrigation rate. However, irrigation level at 100% produced the highest yield as compared with those given by a reduction 60% in both seasons. On the other hand, a reduction 80% gave an intermediate effect in this respect in both seasons.
Furthermore, Table, 4 shows that spraying ascorbic acid at 1000 ppm gave the highest increment in yield (24 and 25 kg/tree) followed by ascorbic acid at 750 ppm (21.67 and 22.32 kg/tree) , ascorbic acid at 500 ppm (20 and 19 kg/tree) and control treatment (16.33 and 16.0 kg/tree) respectively in the two seasons.
In addition, irrigation at 100% combined with ascorbic acid foliar spray at 1000 ppm proved to be the most effective treatment in improving yield (kg)/tree (27.5, and 28.51 kg/tree) followed descending by ascorbic acid foliar spray at 750 ppm (24.67 and 25.32 kg/tree) ascorbic acid foliar spray at 500 ppm treatment (22.5 and 21.5 kg/tree) and control (tap water) (18.32 and 18.0 kg/tree) in both two seasons, respectively in this regard. The same trend noticed with other levels irrigation 80% or 60%. The enhancement effect of ascorbic acid on yield may be attributed that ascorbic acid increased leaf chlorophyll content (Azzedine, et al., 2011). This led to an enhancement of photosynthesis process (Tarraf et al., 1999).which led to more carbohydrate production and that reflected in higher yield. Fruits cracked and fruit sunburned percentages Fruit cracked percentage. 1049 Moreover, ascorbic acid treatments reduced fruit cracked percentage as compared with the control in both seasons. 1000 ppm of ascorbic acid treatment recorded the lowest values of fruit cracked percentage tree against for the control treatment in two seasons.
The interaction between the two tested factors indicated that sustained deficit irrigation combined with ascorbic acid spraying treatments succeeded in reducing fruit cracked percentage in both seasons. Shortly, reduction of irrigation 60 % treatment combined with 1000 ppm ascorbic acid treatment reduced of fruit cracked percentage in this concern.
AS while, 1000 ppm of ascorbic acid treatment with any of irrigation levels (100% , 80% and 60% ) recorded the lowest values of fruit cracked percentage against for the control treatment control with any of irrigation levels (100% , 80% and 60%) in two seasons. Moreover, Ascorbic acid treatments scored comparatively lower values of sunburned percentage than did control treatments. In this respect, 1000 ppm ascorbic acid treatment recorded the lowest values of sunburned percentage against for the control treatment in two seasons.
The interaction between the two tested factors showed irrigation level at 60% combined with ascorbic acid at 1000 ppm high reductive effect on sunburned percentage and surpassed other combinations in reducing sunburned percentage in both seasons.
High level of ascorbic acid at 1000 ppm combined with any of irrigation levels (100%, 80% and 60%) reductive effect on sunburned percentage as compared with the control treatment combined with same irrigation levels previously in both seasons of study. The positive effect of ascorbic acid in reducing cracked and sunburned fruits may be attributed that ascorbic acid has catch all free radicals produced during plant metabolism (Nichloas, 1996). Ascorbic acidincreased IAA content, which stimulates cell division as well as cell enlargement and this in turn in improved plant growth (Hassanein et al., 2009). Ascorbic acid may serve as a potential growth regulator to enhance stress resistance in several species (Khan, 2006). This led to reducing cracked fruit. Furthermore, ascorbic acid reduces sunburn damage in fuji apples (Andrews et al., 1999). The obtained results regarding the effect of ascorbic acid on fruit cracking and sunburned fruits go in line with the findings of Ahmed et al. (1997) showed that ascorbic acid application was controlling the incidence of fruit disorders of apple trees, it was reduced fruit splitting of Manfalouty pomegranate (Ahmed et al., 2014), and Abd-El-Rhman et al., (2017) pointed out that foliar spray ascorbic acid reduced fruit cracked percentage of Manfalouty pomegranate trees.

Fruit physical and chemical properties Fruit weight (g)
Data presented in Table, 6 indicated that the highest increment in fruit weight values were recorded with 100% irrigation followed by reduction irrigation at 80% and 60%, respectively.
Furthermore, the highest increments fruit weight values were recorded with ascorbic acid at 1000 ppm followed by ascorbic acid at 750 ppm compared to control treatment in both seasons.
The interaction effect of irrigation and spray treatment proved that the highest fruit weight values were scored with irrigation level at 100% plus ascorbic acid at1000 ppm, while the lowest values were recorded with irrigation level at 60% with control treatment. Means followed by the same letter (s) within each row, column or interaction are not significantly different at 5% level.

Fruit length (cm)
Table, 6 demonstrates that increasing irrigation level from 60% and 80% to 100 % cause a steady increase in fruit length in both seasons.
Furthermore, it is clear that 1000 ppm ascorbic acid treatment recorded the highest fruit length followed by 750 ppm ascorbic acid, 500 ppm ascorbic acid and control treatments, respectively.
Moreover, the interaction between irrigation levels and spraying ascorbic acid treatments showed that irrigation level at 100% supplemented with ascorbic acid at 1000 ppm spraying treatment scored the highest values of fruit length while the lowest value was recorded with the combination of irrigation level at 60% and control treatment.
Other interaction scored in between rather in this respect.

Fruit diameter (cm)
Table, 7 illustrates that 100% irrigation gave the highest fruit diameter followed discerningly by 80% irrigation level. Meanwhile, irrigation at 60% recorded the lowest fruit diameter.
Furthermore, it is evident that the highest fruit diameter was recorded with ascorbic acid at 1000 ppm followed by ascorbic acid at 750 ppm as compared to control treatment.
In addition, irrigation at 100% combined with ascorbic acid at 1000 ppm spraying treatment proved to be the most effective treatment in improving fruit diameter. On the contrary, reduction irrigation at 60% of (ETc) combined with spray treatment control gave comparatively the lowest values in this respect.

Weight of fruit grains (g)
Table, 7 shows that 100% level of irrigation gave the highest weight of fruit grains followed by descending that irrigation level at 80%. Moreover, reducing that irrigation level at 60% has recorded the lowest of weight of fruit grains.
Furthermore spraying treatment ascorbic acid at 1000 ppm treatment induced the highest weight of fruit grains followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm treatments and control treatment in descending order.
In addition, irrigation at 100% combined with ascorbic acid at 1000 ppm spraying treatment proved to be the most effective treatment in improving weight of fruit grains. On the contrary, 50% irrigation combined with tab water spray treatment gave comparatively the lowest values in this respect. Means followed by the same letter (s) within each row, column or interaction are not significantly different at 5% level. 1052

Flesh (%)
Data presented in Table, 8 shows that the highest increment in flesh percentage values were recorded with 100% irrigation followed by irrigation at 80% and 60%, respectively.
Furthermore, the highest increments flesh percentage values were recorded with ascorbic acid at1000 ppm followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm and control treatments, respectively in the two seasons.
The interaction effect of irrigation and spray treatment proved that the highest flesh percentage values were scored with irrigation level at 100% plus ascorbic acid at1000 ppm, however, the lowest values were recorded with irrigation level at 60% with control treatment. Means followed by the same letter (s) within each row, column or interaction are not significantly different at 5% level. Table, 8 indicates that increasing irrigation level and ascorbic acid spraying rate treatments results in increasing weight of 100 grains in the both seasons.

Weight of 100 grains (g)
Furthermore, irrigation level at 100% plus ascorbic acid at 1000 ppm spraying treatment proved to be the most effective combination in this respect in two seasons. Table, 9 shows that juice volume per fruit was significantly affected by irrigation levels and spraying treatments. Irrigation level of 100% gave the highest juice volume per fruit followed by irrigation at 80% and 60% in both seasons.

Juice volume / fruit (cm 3 )
Concerning ascorbic acid spraying treatments the highest juice volume per fruit was recorded with ascorbic acid at 1000 ppm followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm and control treatments, respectively.
Irrigation level at 100% with ascorbic acid at 1000 ppm spraying treatment proved to be the most effective interaction in increasing juice volume per fruit. On the contrary, irrigation level at 50% combined with tab water spraying treatment gave comparatively the lowest value in this concern.  Means followed by the same letter (s) within each row, column or interaction are not significantly different at 5% level.

Peel thickness (cm)
Data presented in Table, 9 shows that the highest increment in peel thickness values were recorded with irrigation level at 60% followed by irrigation level at 80% and irrigation level at 100%, respectively.
Furthermore, the highest increments peel thickness values were recorded with ascorbic acid at 1000 ppm followed by ascorbic acid at 750 ppm as compared to control treatments in both seasons.
The interaction effect of irrigation and spray treatment proved that the highest peel thickness values were scored with irrigation at 60% plus ascorbic acid at 1000 ppm, whilst the lowest values were recorded with irrigation at 100% with control treatment. Table, 10 illustrate that irrigation level at 60% resulted the highest total sugar value followed descending by 80% and 100% irrigation in the two seasons, respectively. However, significant differences were noticed between the tested sustained deficit irrigation levels.

Fruit total sugars content
Moreover, the highest total sugar was recorded with ascorbic acid at1000 ppm followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm and control spraying treatments, respectively.
Concerning the interaction between the tested irrigation levels, and spraying treatments, 60% irrigation level combined with ascorbic acid at 1000 ppm spraying treatment proved to be the best interaction in this regard.

Fruit T.S.S. (%)
Table, 10 shows that TSS significantly affected by irrigation and spraying treatments. Irrigation level of 60% gave the highest TSS followed by irrigation level at 80% and 100%.
Concerning spraying treatments the highest TSS was recorded with ascorbic acid at1000 ppm treatment, while control treatment recorded the lowest values in this respect.
Irrigation level at 60% with ascorbic acid foliar application at 1000 ppm proved to be the most effective interaction in increasing TSS. On the contrary, irrigation at 100% combined with control spraying treatment gave comparatively the lowest value in this concern. 1054

Fruit total acidity content (%)
Table, 11 shows that 60% irrigation gave the highest acidity value followed by, irrigation level at 80% in descending order. Meanwhile, the lowest fruit acidity value was recorded with irrigation level at 100% in both seasons.
In addition, the highest acidity value was recorded with control followed by ascorbic acid at 500 ppm, ascorbic acid at 750 ppm and ascorbic acid at 1000 ppm, respectively.
Meanwhile, the interaction between irrigation levels and spraying treatments shows that the combination between irrigation level at 60% and ascorbic acid at 1000 ppm gave the lowest value in this concern.
Irrigation level at 60% with spray treatments control (tap water) proved to be effective interaction in increasing acidity followed descending by ascorbic acid foliar spray at 500 ppm, ascorbic acid foliar spray at 750 ppm treatment and spray treatment ascorbic acid at 1000 ppm in both two seasons, respectively in this respect. The same trend noticed with other levels irrigation 80% or 100%. Table, 11 illustrates that significant differences were noticed between the tested regulated deficit irrigation levels. However, full irrigation treatment resulted in the lowest TSS/acidity value, while the ratio was increased by reducing irrigation levels at 80 % and 60% in both seasons.

Fruit T.S.S. /acid ratio
Moreover, the highest TSS/acidity was recorded with ascorbic acid at 1000 ppm followed by ascorbic acid at 750, ascorbic acid at 500 ppm and control spraying treatments, respectively.
Concerning the interaction between the tested irrigation levels, and spraying treatments, 60% irrigation combined with ascorbic acid at 1000 ppm spraying treatment proved to be the best interaction in this regard.  Table, 12 shows that irrigation level at 60% give the highest ascorbic acid value followed by irrigation at 80%. Meanwhile, the lowest ascorbic acid value was recorded with 100% irrigation level. In the first season no significantly between 100 % and 80% irrigation levels.

Fruit ascorbic acid content
In addition, the highest ascorbic acid value was recorded with foliar application of ascorbic acid at1000 ppm followed by ascorbic acid at 750, ascorbic acid at 500 ppm, and control treatment which recorded the lowest values in this respect.
The combined effects of irrigation levels with spraying treatments showed that irrigation level at 60% with ascorbic acid at 1000 ppm treatment were the most effective treatment in increasing ascorbic acid content of juice. Finally, the corresponding ones of 100% irrigation level combined with tab water foliar spray gave the less content of ascorbic acid in juice.
The enhancement effect of irrigation on fruit quality may be attributed that irrigation affected of the most physiological parameters and photosynthesis of olive trees (Masmoudi-Charfi et al., 2010) this led to effect in vegetative growth, yield and productive performance. The obtained results regarding the effect of deficit irrigation on fruit quality go in line with the findings of Abd-Ella (2011) found that the highest irrigation level enhanced fruit quality (fruit weight, diameter, length, TSS and V.C. of pomegranate fruits). Haneef et al. (2014) mentioned that application of irrigation level (100%) registered maximum fruit weight, juice content, TSS : acid ratio of pomegranate fruits. Moreover, higher level of water stress (ETc 50) increased the TSS and decreased the vitamin C in comparison with water irrigation ETc 75 and full irrigation strategies of pomegranate (Parvizi and Sepaskhah 2015). Abdel-Sattar and Mohamed (2017) showed that TSS, TSS/ acidity, and vitamin C were the maximum values at 50% field capacity, while the acidity value was the highest in the treatment of 100% field capacity and yield the highest values of with the treatment of 100% field capacity of pomegranate trees.
The enhancement effect of ascorbic acid on fruit quality may be attributed that firstly, ascorbic acid increased leaf area and leaf chlorophyll content (Azzedine, et al., 2011). That is lead to enhancement photosynthesis process (Tarrafet et al., 1999).which reflected in more carbohydrate production and consequently improved fruit quality. Secondly, ascorbic acid increased IAA content which stimulates cell division as well as cell enlargement (Hassanein et al. 2009 and Abd-El Hamid 2009). Furthermore, auxin was increased fruit quality (Ragab, 2002). Thirdly, ascorbic acid mitigates the adverse effect on plant growth by enhanced proline accumulation (Azzedine, et al., 1997). The proposed function of the accumulated proline is osmosis regulation which has an adaptive mechanism to environmental stress (Aspinall and Paleg 1981). So that the increase in proline leads to enhancement leaf chlorophyll content and that reflected in more carbohydrate production through photosynthesis process and consequently improved fruit quality. The obtained results regarding the effect of ascorbic on fruit quality go in line with the findings of Atef (2018) on pomegranate. He mentioned that foliar sprays of ascorbic improved fruit quality of pomegranate fruit. Also, enhanced fruit quality of pomegranate trees (Fayed 2010& Ahmed et al., 2014.
Table12:-Effect of sustained deficit irrigation and foliar application of ascorbic acid on ascorbic acid (mg/100 ml juice) and Water used efficiency (Kg.m -3 .tree -

Water use efficiency (kg/m 3 )
Table, 12 demonstrates that irrigation at 60% produced higher positive effect on water used efficiency followed by irrigation 80% and finally by the corresponding ones received irrigation at 100%. Furthermore, significant differences were found between spraying treatments in the two seasons, the highest increments flesh percentage values were recorded with ascorbic acid at1000 ppm followed by ascorbic acid at 750 ppm, ascorbic acid at 500 ppm and control treatments in the two seasons.
Finally, the interaction between the two tested factors showed that treatment 100% irrigation combined with ascorbic acid 1000 ppm spraying treatment proved to be the best interaction in this regard.
The obtained results regarding the effect of deficit irrigation on fruit quality go in line with the findings of Khattab et al. (2011) indicated that low irrigation level of 13 m 3 /tree/year recorded the highest water use efficiency of pomegranate trees. Intrigliolo et al. (2012) showed that deficit irrigation caused increasing water use efficiency of pomegranate trees.
The obtained results regarding the effect of deficit irrigation on fruit quality go in line with the findings of Bakry et al. (2013) they mentioned that increasing foliar application levels of ascorbic acid significantly increased water use efficiency. And the interaction between the water irrigation requirements of (80% irrigation) and (300 mg/L) foliar application level of ascorbic acid gave the highest values of water use efficiency of wheat.

Conclusion:-
Sustained deficit irrigation is pronounce positive effect water used efficiency to saving water and protecting of water resources in the future, it is preferable to use the strategy of sustained irrigation deficit water in arid and semiarid areas. We can be reducing negative impacts sustained irrigation deficit by using spraying by ascorbic acid.