الفهرس 
INTRODUCTION
Fruits physical characteristicsOnly 14 pages are availabe for public view
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Abstract
The objective of the present work is to investigate the possibility of producing strawberry fruits (Fragaria x ananassa) cv. (Sweet charlie) under soilless conditions (vermiculite: peat moss: sand 1:1:1 v) using Cooper nutrient solution. In addition, an attempt was carried out to accelerate and enhance vegetative growth and consequently fruiting earliness and total fruit yield using different concentrations of Amino Acids (AA) and/or vitamins (Vit) mixtures and a combination of both of them, as natural growth bio-stimulators. The physical and chemical characteristics have been taken into consideration.
The experiment was carried out on completely randomized design with 27 treatments arranged in 1 x 3 x 9 factorial scheme; one cultivar; three methods of application (foliar spraying (S), addition to the nutrient solution (Ad), and (S + Ad) and nine concentrations of AA and/or Vit mixtures.
The growing plants were treated three times during vegetative growth with each of the following mixtures.
• 150 (I) and 300 (II) ppm AA mixtures consisted of equal portions of (proline, phenylalanine, lysine, methionine, tryptophan and glutamine (amide)).
• 100 (III) and 200 (IV) ppm vitamin mixtures consisted of equal quantities’ of (thiamine-HCl, riboflavin, pyridoxine and nicotinic acid).
• Mixtures of equal volumes of I+III, I+IV, II+III and II+IV
The experiment was carried out through two successive seasons 2011 and 2012. The experiment has been divided into two sections.
Section I: following up the response of the morphological and chemical characteristics of strawberry plant foliage
Section II; concerning the improvement and response of fruit yield, physical and chemical attributes of the resultant fruits. The main results could be summarized in the following statements:
SECTION I: Morphological and chemical characteristics of strawberry foliage.
1-Fresh weight (g/plant), plant height (cm), and No. of leaves/plant
The highest positive significant impact has been attained in case of fresh weight compared with the other parameters; plant height and No. leaves/ plant. Addition of AA300 ppm resulted in the highest values of fresh weight, which accounted by 3.0 – 2.5 times than those of the corresponding control in the first and second season, respectively.
2-Moisture %, dry matter (g/plant), ash (%) and pigments content (mg/g FW)
No-significant variations have been recorded in case of moisture, ash, photosynthetic pigments (Chl a, b, Chl a/b and carotenes) due to application of most treatments. On the other hand, dry matter positively responded in significant manner due to most treatments.
However, this may mean that application of AA and /or Vit mixture may exert their bio-stimulatory influence on the morphological characters especially fresh weight without altering photosynthetic pigments and ash in significant manner.
3- Carbohydrates fractions (g/100g DW)
It is interesting to note that all treatments exerted significant increases in non-reducing sugars, total soluble sugars and total carbohydrate, compared with control one, and this hold true for all methods of application.
The comparison among the different carbohydrate fractions, show the prevalence of total soluble sugars followed by non-reducing sugars, polysaccharides, and finally reducing sugars which accumulated in relatively low levels, and this holds true for the two successive seasons. The levels of the different carbohydrate fractions in the resultant strawberry plant differed from one season to another and this is obvious in case of non-reducing, total soluble sugars and, to some extent, total carbohydrates.
4- Total free amino acids (TFAA) (g/100g DW) and Total phenols (TP) (mg/100g FW)
Data reveal such significant increases in (TFAA) due to most treatments with AA and/or Vits mixtures compared with control, which gave the lowest values.
Also, data reveal the richness of TP in the produced strawberry foliage (herb), in case of all treatments investigated, and this hold true for all methods of application. The lowest TP values were achieved in case of control. While the highest significant values were obtained, due to spraying 300 ppm amino acid mixture. Therefore, the remarkable quantities of TP in strawberry foliage (waste products after harvesting fruits) may throw some lights upon their economic value as rich source of natural total phenols.
5- N, P and K content (g/100g DW)
Only, nitrogen content responded significantly to the investigated treatments regardless the methods of application. Most of treatments resulted in significant high levels of N compared with control treatment.
Concerning with P and K, data indicate, almostly, no-significant variations compared with control, and this hold true for most treatments in case of the first and second season. SECTION 2: Concerns with fruiting; the yield, physical and chemical characteristics (nutritional quality) of the resultant fruits
1- Early and, total fruit yield, No. of fruits/plant, fruit weight and fruit size
In general, treatments exhibited the highest significant values of most of the forementioned parameters especially early and total yield, compared with all treatments investigated.
An inverse relationship between No. fruit/plant on one hand and the weight and size of fruits on the other hand.
The marvelous results have been achieved by foliage spraying with AA300 ppm, which produced the highest significant early and total fruit yield, and No. of fruits/plant, with moderate fruit weight and size. However, this treatment, mainly, enhanced fruiting earliness, as early fruit yield reached 5 and 3.7 times than the corresponding control, in the first and second season respectively. But the treatment increased the total yield by only about 1.9 and 1.7 times than those of control in the same two seasons, respectively.
Our findings may mean that the environmental and cultivation conditions, have determined, to great extent, the early and total fruit yield.
2- Fruit moisture, dry matter and ash
Dry matter exhibited significantly high values in case of most investigated treatments compared with those of the corresponding control in the same season.
Concerning the moisture and ash %, data indicate nearly non-significant differences due to application of AA and/or Vit mixtures, as most treatments exhibited closed values. It is worthy to state that moisture % (at 105 Co) of the fruits of the different treatments ranged between 85.82 and 90.98 % in the first season and 87.69 – 91.41 % in the second one. 3- Fruit firmness, juice pH, Titratable Acidity, Total Soluble Solids and TSS/TA ratio
Concerning fruit firmness, data showed a significant good quality of strawberry fruits due to all treatments compared with the corresponding control, which showed the lowest values of fruit firmness, and this holds true for both the first and second season.
Spraying with AA 300 ppm, data showed remarkable increases in the firmness of the resultant fruits (good quality) accounted by 19.45 and 15.3 % than those of control in the first and second season, respectively.
Concerning juice pH, TA, TSS and TSS/TA in the first and second season data reveal that, no distinctive differences could be differentiated among most treatments. The values of these parameters varied from one season to another according the prevailed environmental conditions during each season.
4- Carbohydrates fractions
Data reveal significant increases, mainly in reducing, non-reducing and total soluble sugars together with total carbohydrates compared with the control treatment.
Total soluble sugars (TSS) consisted mainly of non-reducing sugars (NRS) compared with reducing sugars (RS), as NRS accounted by about one and half to two times of (RS). Polysaccharides came at the second order after (TSS). Total carbohydrates ranged between 34.76 to 52.75% in first season and 36.2 – 52.45 % in the second one.
No clear variations have been noticed in the different carbohydrate fractions in the resultant fruits from one season to another in the present study.
5- Total soluble proteins (TSP), and total free amino acids (TFAA)
Data indicated positive response of both (TSP) and (TFAA) which significantly increased due to all treatments compared with control which showed the lowest levels of both of them for both the two successive seasons.
6- Total phenols, vitamin C and anthocyanins
Our findings clearly have revealed that both total phenols and vitamin C positively responded in significant manner to the all investigated techniques more than anthocyanins in case of all treatments and methods of application. Their response could be arranged in descending order as follows; total phenols > vitamin C > anthocyanin pigments.
7- The scavenging capacity (SC)
Dealing with the scavenging capacity of the antioxidants existed in the methanolic extracts of fruits, data revealed that most of the investigated treatments enhanced significantly the (SC) compared with control which exhibited the lowest values of (SC) at all concentrations (50, 100 and 200 μg/ml). Direct correlation has been found between both (TP) and Vit C on one hand and (SC) on the other hand i.e. (SC) increased by increasing both TP and Vit C concentrations, but no linear relationship has been observed.
8- Identification and determination of pelargonidin-3-glucoside using HPLC technique:
The main conclusion which must be taken into consideration, is that, this compound represents the predominate anthocyanins fraction compared with the other anthocyanins. Most of treatments and methods of application resulted in somewhat high levels of it compared with those of control.
The treating plant with combined amino acids + vitamins mixtures may exert such synergetic effect on enhancing the biosynthesis and accumulation of this compound in the investigated fruits rather than each of them did. 9- Macronutrients; N, P, K (g/100g DW) and micronutrients; Mn, Fe, Mg (mg/100g DW) and Ca (g/100g DW)
No-significant variations have been detected due to treating with most AA and/or Vit mixtures using the different applying techniques. Concerning with the abundancy of these elements in the resultant strawberry fruits, data revealed the prevalence of (N) followed by (K) and (P) later (macronutrients) and the superiority of both (Ca) and (Mg) compared with the other micronutrients; (Fe) and (Mn).
RECOMMENDATIONS
Cultivation of strawberry (cv. Sweet charlie) under soilless conditions may be succeeded when provided with the good choice of substrate media, such as the chosen media used in the present study; and proper nutrient solution used (Cooper solution). Also by treating the growing plants by convenient natural growth bio-stimulators (AA and/or Vit mixtures). For enhancing vegetative growth and improving both early and total fruit yield as well as, enhancing the physical and chemical characteristics of the resultant fruits (nutritional quality). However, one can put stress on the following findings:
• The richness of total phenols of the remained strawberry foliage (herb) due to most treatments, which may be considered as commercial source of these phenolics for medical and other industries.
• The enhancement of vegetative growth parameters, early and total fruit yield, and their characteristics varied from one treatment to another and according to the method of application and have been influenced by the prevailed environmental conditions, i.e. from one season to another .
• Most of fruit attributes responded significantly, leading to improving their physical and nutritional quality; such as fruit firmness (responsible for increasing shelf life); all carbohydrate fractions (indicators for sweetness and flavor); total soluble protein and total free amino acids (needed for the different metabolic processes); total phenols, Vit C and anthocyanins (main antioxidants responsible for the high scavenging capacity that have huge biological potentialities in humans). On the other hand, the taste parameters (juice pH, TA %, TSS % and TSS/TA) changed nearly in non-significant manner.
Finally one can recommend foliar spraying with AA 300 ppm , for improving the morphological characters of strawberry foliage , especially, plant height, No. of leaves/plant and nitrogen content rather than the other treatments did, including control. Also the remainder foliage herb (after harvesting fruits) contained the highest significant values of total phenols. Also this treatment produced the highest significant values of early and total fruit yield, No. fruits/plant with moderate fruit weight and size. Fruit firmness, antioxidants, and in turn, scavenging capacity, all carbohydrate fractions, total soluble protein and total free amino acids, showed the highest significant values compared with control . However further detailed studies still needed, to visualize the optimum and suitable conditions for cultivation strawberry plants into soilless substrate media at commercial scale.