الفهرس 
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Abstract
The present study was carried out on three month old potted plants (suckers) of Grand Nain and Williams banana cultivars in green house at El-Kanatwer Horticultural Research Station located at El-Qualubia Governorate during two successive of 2006 and 2007 seasons. It was aimed to investigate salt tolerance of two banana cultivars and possibility of minimizing the depressive effect of salt stress. Thus, two experiments were conducted using the complete randomized block design with five replications, whereas each was represented by 2 plants (grown individually in 35.0 cm. diameter plastic bags filled with specific weight (10 k.g.) of clay and sand mixture at 2:1 ratio by volumes.
V-I- Experiment I:
Effect of salinity concentration, sodium adsorption (S.A.R.) and chloride level (CI:SO4 ratio ) on plants of two banana cultivars.
Investigated treatments were representative of different 18 combinations between two banana cvs. (Grand Nain and Williams), and 2 levels of saline concentrations (2000 and 3000 ppm); two sodium adsorption ratios(3&6) and two Cl : SO4 ratios (low& high), beside irrigation with tap water as control V-II- Experiment II :
Effect of foliar spray with some nutrient elements
(P, K & Zn) on banana plants grown under saline solution (irrigated with 3000ppm solution of SAR 6 and two levels of CI:SO4 ratio, (low & high).
Salt tolerance of banana plants was studied through investigating the influence of (16) treatments representative of various combinations between 2 banana cultivars (Williams and Grand Nain), grown under salt stress 3000ppm of SAR 6 and two levels of Cl:SO4 ratios (low & high) and foliar spray with 3 nutrient elements solutions (250ppm phosphorus as H3PO4, 250ppm potassium and 1000ppm ZnSO4), monthly adopted from May 15th up to mid October of both seasons.
Specific and interaction effects of the investigated factors and their combinations included in the aforesaid 1St & 2nd factorial experiments were studied through the response of the following measurements:
1-Growth parameters:
Pseudostem (length & circumference); (average leaf area & number of roots/plant); (total number of leaves&yellowish or dry leave s/ plant); fresh and dry weights of various transplant organs (leaves, pseudostem, corn-is and roots) were the investigated growth measurements in 1St and 2nd experiments .
2-Chemical analysis:
Photosynthetic pigments (foliar pigments); proline contents and nutritional status (leaf, N, P, K, Ca, Mg, Na, Fe, Mn and Zn contents) in response to the studied treatments of 1st and 2nd experiments were investigated.
3- Anatomical structure:
Leaf structures of two banana cvs. (Williams. and Grand Nain cvs.)irrigated with saline water were investigated regarding the effect of salt concentration, SAR, chloride levels (1st season).
Thickness of cuticle and epidermis layers of both lower and upper leaf surfaces; mesophyll (palisade & spongy tissues), number of palisade & spongy tissues, thickness of fiber tissues (upper and lower the vascular bundle), thickness of phloem & xylem tissues in vascular bundle and diameter of widest xylem vessel in the vascular bundle were the, investigated characteristics through microscopic examination of leaf crosses section.
V.I. Experiment I: Effect of different salt concentrations, S.A.R. ratio and chloride levels (C1:SO4 ratio) on plants of 2 banana :
V. II - Growth measurements :
In this regard 14 growth parameters namely :( Pseudostem (length & circumference); (average leaf area & number of roots/plant); (total number of leaves & yellowish or dry leaves/ plant); fresh and dry weights of various transplant organs (leaves, pseudostem, corms and roots) in response to specific effect of four studied factors (banana cultivar, salt concentration; SAR ratio and chloride levels (Cl : SO4 ratio) as well as interaction effect of their possible combinations were investigated during both 2006 and 2007 seasons. - Specific effect:
1- Regarding the specific effect of banana cultivar, data obtained
during both seasons revealed that Grand Nain cv. was the superior with all the investigated growth measurements while Williams cv. was the inferior with (length & circumference of pseudostem); (number of roots & average of leaf area /plant); (total number of leaves) and fresh and dry weights of various organs (leaves, pseudostem, corms and roots) during two seasons of study.
2-As for the specific effect of salt concentration; data obtained displayed obviously that increasing salt concentration or increasing ratios of either S.A.R. (from 3 to 6) or (CI:Sat ratio) in irrigation water significantly decreased all the investigated growth measurements under study i.e., (length & circumference of pseudostem); ( average leaf area & total number of roots); ( total number of leaves) and both fresh /dry weights of various organs (leaves, pseudostem, corms and roots).
B. Interaction effect:
Data obtained revealed that specific effect of each investigated factor was directly reflected on its own combinations. Herein, the Grand Nain banana plants irrigated with 2000 ppm salt concentration x SAR3 and low chloride level (CI:Sat ratio) exhibited statistically the greatest values of various growth parameter for all saline stressed plants during the two seasons of study. On the contrary, the least values of the investigated growth measurements were always in concomitant to those banana plants subjected to the 3000ppm salt entration x SAR 6 x high chloride level (CI:SO4 ratio), regardless of cultivar. However, there was a gradual tendency pointed out that the rate of reduction in growth measurements of Grand Nain plants was less pronounced as compared to the analogous one of Williams cultivar.
V. I. II. Chemical composition:
V. I. II. 1.Photosynthetic pigments (foliar pigments) :
Data obtained regarding leaf photosynthetic pigments contents (chlorophyll A; B and carotenoids compounds) of banana plants as influenced by the specific and interaction effects of banana cultivar, salt concentration, SAR and chloride CI:SO4 ratios in irrigation water and their possible combination revealed that:
A-Specific effect:
1-Concerning the specific effect of banana cultivars on leaf chlorophyll (A&B) and carotenoids compounds all were generally higher in Grand Nain leaves than those Williams cvs. during the study.
2-The obtained results revealed that, chlorophyll (A & B) and carotenoids compounds in banana leaves, were progressively decreased by raising any of salts concentration, sodium adsorption ration (S.A.R.) or chloride level (CI:Sat ratio) in the irrigation water .
B. Interaction effect:
It could be generally concluded that Grand Nain plants irrigated with 2000 ppm salt concentration x SAR 3 with low chloride level (CI:SO4 ratio) had the richest leaves for both ophyll (A & B) and carotins. The reverse was true with Williams cvs. irrigated with salt concentration at 3000 ppm x SAR 6 of higher level of chloride. Moreover, other combinations were in between.
V.1.11.2. Proline content.
1-Data obtained displayed that proline content responded specifically to banana cultivar, whereas. Williams cultivar was the richer .
2-The obtained results revealed that, proline content progressively increased by raising any of salts concentration, S.A.R. and chloride level (C1:SO4 ratio) during two seasons of study.
B- Interaction effect:
The highest level of proline content was in closed relationship to Williams plants irrigated with 3000ppm x SAR 6 and higher Cl:SO4 ratio as compared with other combinations of saline solutions, however, all salinity stressed plants were richer and exceeded the analogous ones of tap water irrigated ones (control) during two seasons of study.
V.I.111.3. Leaf mineal composition:
Data obtained regarding the leaf N; P; K; Ca; Mg; Na; Fe; Mn and Zn contents of banana plants in response to specific and interaction effects of banana cultivar; salt concentration sodium adsorption ratio (S.A.R.); chloride level (Cl:SO4 ratio) in irrigation water and their possible combinations revealed the following:
Summary and Conclusion A-Specific effect:
1- Concerning the specific effect of banana cultivar, data obtained during both seasons revealed that Grand Nain cultivar exceeded statistically the other cultivar, (Williams),regarding their leaf N; P; K; Mg; Fe; Mn and Zn contents. However, with both leaf (Ca&Na) contents the trend took the other way around during two seasons.
2- Results showed that increasing any of either (salt concentrations; S.A.R. or chloride level decreased significantly leaf N; P; K; Mg; Fe; Mn and Zn contents but significantly increased leaf Ca and Na coOntents as compared to control during two seasons of study.
B-Interaction effect:
A significant variations in leaf mineral content due to interaction between banana cultivar; salt concentration; sodium adsorption ratio (SAR) and chloride level (CI:SO4 ratio) were detected. Meanwhile, Grand Nain cultivar x 2000ppm salt concentration of S.A.R.-3 and lower chloride level (CI:Sat ratio) showed the highest value of leaf N; P; K; Mg; Fe; Mn and Zn contents and lowest value of leaf Ca and Na contents as compared to the other saline stress combination. On the other hand; Williams cv. x 3000ppm x SAR 6 x higher chloride level had the lowest values of leaf N; P; K; Mg; Fe; Mn and Zn contents and higher values of leaf Ca and Na contents during two seasons of study. V.II. Experiment II:: Effect of some nutrient foliar sprays on saline stressed banana plants (irrigated with 3000ppm saline solution of SAR 6 and two chloride levels):
In this regard specific and interaction effects of three investigated factors i.e., banana cultivar (Williams and Grand Nain); kind of nutrient foliar spray (P & K at 25Oppm and Zn at 100ppm); two chloride levels (low & high) and their possible combinations were studied regarding the influence on some growth measurements and chemical composition.
The obtained results could be summarized as follows: V. II. I. Growth measurements:
Pseudostem (length & circumference); (number of root per plant & average leaf area); (total number of leaves & Yellowish or dry leaves: total) and fresh and dry weights of various plants organs (leaves; pseudostem, corms and roots) were the investigated growth measurements.
A- Specific effect:
1-Concerning the specific effect of banana cultivar, data obtained during both seasons displayed that Grand Nain exceeded Williams cvs. in all growth parameters except rate of yellowish leaves.
2-As for the specific effect of nutrient foliar spray, data obtained during both seasons displayed that the three nutrient foliar sprayed (P, K and Zn) increased significantly all growth measurements as compared to control plants (unsprayed salt sed). However, Zn was more effective for most measurements pseudostem length.
3-Increasing chloride levels (Cl:SO4 ratio) in irrigation water resulted in reducing all growth measurements (pseudostem length & circumference of pseudostem), (No. of roots & average leaf area), (No. of total leaves) and fresh / dry weights of thee plant organs.
B- Interaction effect:
1-A significant interaction effect was detected as a result of the combination between banana cultivar, sprayed nutrient element and chloride level. Hence, Grand Nain plant sprayed with Zn at 100ppm and irrigated with salt solution of 3000ppm concentration SAR 6 and low chloride level showed the highest increase in (pseudostem length& pseudostem circumference); (No. root & average of leaf area); (total number of leaves) and fresh and dry weights of (leaves, pseudostem, corms and roots) as compared to the plant under salt stress during two seasons of study
2-The least values of all investigated growth measurements were always in closed relationship to such saline stressed plants of Williams cv. ratio without spray treatments especially at higher Cl:SO4.
V. II. II. Chemical composition:
V. II. IL 1.Photosynthetic pigments (foliar pigments)
Leaf chlorophyll (A & B) and carotenes of salt stressed banana plants in response to specific and interaction effects of banana cultivar; sprayed nutrient elements; chloride level (C1:SO4 ratio) in irrigation water and their possible combinations were investigated.
A-Specific effect:
Data obtained during both seasons displayed that the three photosynthetic pigments (foliar pigments) followed the same trend regarding the specific effect of either banana cultivar or sprayed nutrient element and chloride level (Cl:SO4 ratio) in irrigation water .Hence, Grand Nain leaves were statistically the richest while Williams leaves were the poorest in their 3 pigments contents. Meanwhile, all the 3 sprayed nutrient increased the 3 foliar photosynthetic pigments, while Zinc foliar spray was more effective followed in a descending order by potassium in concern. Increasing chloride level (C1:SO4 ratio) in irrigation water decreased significantly 3 photosynthetic pigments during two seasons of study.
B-Interaction effect:
Data obtained during both seasons revealed obviously that specific effect of each investigated factor i.e., banana cultivar; sprayed nutrient element: and chloride level (Cl:SO4 ratio) in irrigation water was directly reflected on their own combinations. Herein, the Grand Nain plants under salt stress of low chloride level and sprayed with Zinc at 100 ppm exhibited statistically the greatest values of chlorophyll (A & B) and carotenaids compounds. The reverse was true with unsprayed Williams salt stressed plants with higher Cl:SO4 ratio . V.II.11.2. Proline content. A- Specific effect:
Concerning the specific effect of banana cultivar , sprayed nutrient element and C1:SO4 ratio data obtained revealed that Williams plants had statistically the richest leaf proline content,
the reverse was found with Grand Nain cvs. Meanwhile, P & K and Zn foliar spray significantly decreased proline content while, Zinc was the most effective than either P or K foliar spray in this concern. In addition, increasing chloride level (Cl:Sat ratio) in irrigation water didn’t affect proline content during two seasons of study.
A- Interaction effect
The highest level of proline were always in concomitant to leaves of unsprayed (salt stressed) Williams plants which
irrigated with salinized water of higher chloride level during two seasons of study . The reverse was true with sprayed salinity stressed Grand Nain plants especially at lower CL:SO4 ratio.
V.II.11.3. Leaf mineal composition:
1-Referring the specific effect of banana cultivar, data obtained during both seasons revealed that Grand Nain cultivar had the richest leaves N, P, K, Mg, Fe, Mn and Zn contents from one hand, associated with the poorest leaves Ca and Na contents from the other. The reverse was true with Williams cultivar during two seasons of study.
2-As for the specific effect of sprayed nutrient elements (P, K and Zn), it is quite clear that P; K or Zn foliar spray for salt stressed banana plants statistically increased leaf N, P, K, Mg, Fe, Mn and Zn contents as compared with unsprayed salt stressed (control) ones while the reverse was true with leaf —Ca and Na contents during two seasons of study.
3-Data obtained revealed that P foliar spray was the most effective for increasing leaf P and Fe while Zinc foliar spray was the superior for leaf N; Mg; ;Mn and Zn contents. On the other hand foliar spray with any of three nutrients exhibited significantly an obvious reduction in both Ca and Na levels, where the P and Zn showed the most reductive effect for Ca and Na respectively . In addition p foliar spray showed the highest value of P content.
4-Increasing chloride level (C1:SO4 ratio) in irrigation water significantly decreased leaf N, P, K, Mg, Fe, Mn and Zn contents but increased leaves Ca and Na of salt stressed banana plants during two seasons of study .
B- Interaction effect:
1-A significant response to interaction effect of various combinations between banana cultivar, sprayed nutrient element and chloride level (Cl:SO4 ratio) in irrigation water. However, combinations represented (Grand Nain x K x low chloride level); (Grand Nain x P x low chloride level); (Grand Nain x Zn x low chloride level) exhibited the highest leaf (N & K); (P & Mg) and (Fe & Zn), respectively . In addition, unsprayed Williams plants irrigated with 3000 ppm salt solution with high chloride level gave the highest value of leaf Ca & Na contents during two seasons of study.
2-Data obtained revealed that (unsprayed Williams cv, x high chloride level); (Grand Nain cv. x Zn x low chloride level) and chloride level) showed the highest values of leaf (N & P); (N, P, K, Mn & Zn); (Ca & Na) and Mg contents, respectively during two seasons of study.
V.11.4. Leaf anatomical structure:
In this regard some anatomical features of leaf blade of two banana cvs. (Williams and Grand Nain) were microscopically examined during 1st experimental season (2006) to study the following :
Salinity increased thickness of both cuticle and epidermis layers of two leaf surfaces as well as palisade tissue thickness. However, spongy tissue thickness and xylem rows in vascular bundle were decreased in salt stressed banana plants of two banana cvs. as compared to the analogous ones of tap water irrigated plants (control).
2- Effect of P; K and Zn spray on leaf anatomy of salt stressed banana plants:
Any of P; K or Zn sprayed solution succeeded at variable degrees to alleviate the harmful effect of salinity stress occurred in leaf anatomical characteristics. Herein, thickness of (cutical & epidermis layers) of two leaf surfaces and palisade tissue were obviously decreased as compared to the corresponding ones of unsprayed salt stressed plants for two banana cultivars. However, spongy tissue and xylem rows in vascular bundle were decreased. Such trends were true with variable degrees of differences exhibited in rate of response that depended mainly on concerned anatomical character, sprayed element and banana cultivar itself. from obtained results of the present dissertation it could be recommended for nursery men that under shortage of available fresh water that saline solution of relatively lower level of salt concentration (2000 ppm); SAR 3 and Cl:SO4 could be safely used for irrigation purposes. Moreover, foliar sprays of salt stressed banana plants with P; K and Zn solutions minimize to great extent the harmful influence of salinity stress and consequently improve growth; nutritional statues and anatomical characteristics.
Summary.