الفهرس 
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Abstract
This study was carried out on fruitful trees and young budded transplants of Washington navel orange Cv. during two consecutive seasons throughout 2008,2009 and 2010 years in the Experimental Station of Faculty of Agriculture, Benha University at Moshtohor, Toukh region, Kaliobia Governorate. Two experiments were included as follows: br V.I. First experiment ”effect of some bio - organic nutrient compounds on fruitful Washington navel orange trees”: br In this experiment, the influence of application with some bio and organic nutrient compounds (a-bio-stimulant / Biomagic, b-Hammer and c-Piptone) on fruitful (7 year old) Washington navel orange trees budded on sour orange rootstock and grown in clay loamy soil was investigated during 2009 and 2010 experimental seasons. br Each nutrient compound was applied either solely or combined with other -#102;-#114;-#111;-#109; one hand and supplied either a foliar spray or soil drench application -#102;-#114;-#111;-#109; the other. Thus, the investigated nutrient compound treatments were as follows: br 1- Control (water spray). br 2- Foliar spray with biostimulant (Biomagic) at 7.5g/liter. br 3- Foliar spray with peptone at 0.5g/liter. br 4- Foliar spray with Hammer at 1.5g/liter. br 5- Soil drench application with Hammer at 1.5g/liter. br 6- Foliar spray with Biomagic (7.5g/L) + Hammer soil drench (1.5g/L). br 7- Peptone foliar spray (0.5g/L) + Hammer soil drench (1.5g/L). br Taking into consideration that all investigated nutritive treatments even control (water spray) were applied 6 times at one month interval (starting -#102;-#114;-#111;-#109; early February up to July) after the N, P, K fertilizers program adopted in the farm had been provided during each season. Moreover, 3 liters proved to be sufficient for covering the whole foliage of tree canopy, consequently solution of a given nutritive substance applied either foliar or soil drench was provided at 3.0 liters/tree for each treatment 6 times / season. The complete randomized block design with four replications was used. br The response of Washington navel orange trees to the differential investigated nutritional treatments was evaluated through determining changes exhibited in the following characteristics: br V.I.A. Vegetative growth measurements: br In this regard number of developed shoots per one meter of every tagged limb, average shoot (length - thickness), number of leaves/shoot and average leaf area were the investigated growth parameters. br V.I.B. Fruiting measurements: br Fruit set %, Percentage of fruits -#68;-#82;-#79;-#80; - their retention, yield (weight in kg or number of harvested fruits / tree) and fruit quality (physical - chemical properties) in response to investigated treatments were concerned. Hence, average fruit weight, size(volume), dimensions (Polar - equatorial diameters), shape index, juice volume and peel thickness, as well as fruit juice TSS, total acidity, TSS/Acid ratio, total sugars % and ascorbic acid (V.C.) were the investigated fruit physical and chemical properties. br V.I.C. Leaf chemical composition: br Leaf Photosynthetic pigments (chlorophyll, A, B and carotenes) and mineral constituents (N, P, K, Ca, Mg,Fe,Mn and Zn contents) were the investigated leaf chemical composition in this respect. br V.II. Second experiment ”effect of some citrus rootstocks on young budded Washington navel orange transplants”. br Potted experiment on young budded Washington navel orange transplants grown in glass house of Faculty of Agriculture, Benha University was conducted to investigated the influence of some citrus rootstocks during two successive 2008-09 and 2009 -10 experimental seasons. Sour orange, Volkamer lemon and Balady lime were the investigated citrus rootstocks, -#119;-#104;-#101;-#114;-#101; the complete randomized block design with four replications was employed. The response was evaluated through differences in the following measurable characteristics: br V.II.1. Morphological parameters: br a- success percentage of Washington navel orange grafts (shield budded) on three citrus rootstocks after 3 months of budding operation. br b- Scion growth measurements: br Length - diameter at 5 cm. above union zone, number of leaves and average leaf area were the investigated four scion vegetative growth parameters. br V.II.2. Scion Leaf chemical analysis: br In this regard leaf Photosynthetic pigments (chlorophyll, A, B and carotenoids compounds) and leaf mineral composition (N, P, K, Ca, Mg,Fe,Mn and Zn contents) of scion were determined. br V.II.3. Anatomical study of union zone: br Healing and development of union zone tissue were anatomically examined after 15, 30, 60, 120 and 240 days -#102;-#114;-#111;-#109; shield budding operation. br Generally, obtained results could be summarized as follows: br V.I. First experiment ”effect of some bio - organic nutrient compounds on fruitful Washington navel orange trees”: br V.I.A. Vegetative growth measurements: br Obtained results declared that all investigated growth measurements of Washington navel orange trees (number of developed shoots per one-meter limb, shoot length - diameter, number of leaves per shoot and average leaf area) were significantly increased by all bio - organic fertilizers treatments. However, rate of increase varied -#102;-#114;-#111;-#109; one investigated treatment to another, whereas the Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench (6th treatment) was statistically the superior, descendingly followed by the Biomagic 7.5g/L foliar spray solely and/or( Peptone 0.5g/L spray + Hammer 1.5g/L soil drench) i.e., 2nd - 7th treatments which ranked statistically 2nd . br In addition, other investigated bio - organic nutritive compounds treatments were in between. On the other hand, the rate of response was relatively differ -#102;-#114;-#111;-#109; one to another parameter of various investigated vegetative growth measurements. br V.I.B. Fruiting measurements: br Data obtained during both experimental seasons revealed that fruit set %, fruits retention%, fruits drop% and yield (weight in kg or number of harvested fruits per tree) followed two conflicted trends regarding their response to the bio - organic fertilizers treatments. Hence, all investigated treatments increased significantly both fruit set % and fruits retention % (at different measuring dates) as well as, yield (No. - weight of harvested fruits/tree) as compared control, while the reverse was true with fruit drop%. Anyhow, Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench exhibited statistically the highest increase in (fruit set, fruits retention and yield/tree) and the severest reduction rate in fruits drop%. However, both Peptone 0.5g/L spray + Hammer 1.5g/L soil drench and Biomagic 7.5g/L foliar spray solely, descendingly ranked 2nd and 3rd , respectively. other treatments were significantly less effective. br V.I.C. Fruit quality: br Fruit weight, size (volume), dimensions (Polar - equatorial diameters), shape index, juice volume and peel thickness were the investigated fruit physical properties regarding their response to the different bio - organic nutritive treatments. Obtained results revealed clearly that all fruit physical characteristics increased significantly by all investigated bio and organic fertilization treatments. The Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench applied was statistically the superior, descendingly followed by Peptone 0.5g/L foliar spray + Hammer 1.5g/L soil drench and Biomagic 7.5g/L foliar spray solely . On the other hand, Peptone 0.5g/L foliar spray solely and Hammer 1.5g/L applied solely (either foliar or soil drench) ranked last. However Peptone was more effective than Hammer as each applied solely -#102;-#114;-#111;-#109; the statistical standpoint (regardless of application method for later nutritive compound). br Nevertheless, trend of response for fruit weight, size, dimensions and juice volume was firm, while both fruit shape index and peel thickness was less pronounced and in most cases their differences didn’t reach level of significance. br Fruit chemical properties: br Obtained results displayed clearly that all fruit juice chemical properties under study i.e., TSS %, TSS/Acid ratio, total sugars % and vitamin C content except total acidity % exhibited the highest values with Washington navel orange trees subjected to Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench followed by those treated with Peptone 0.5g/L foliar spray + Hammer 1.5g/L soil drench. Other investigated treatments were less effective and in some cases didn’t affect fruit juice properties than control, especially TSS/Acid ratio. br V.I.D. Leaf chemical analysis: br Leaf Photosynthetic pigments: br Data obtained during both seasons revealed that all investigated treatments increased leaf chlorophyll, A, B and carotenes contents than control. However, both treatments of Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench and Peptone 0.5g/L foliar spray + Hammer 1.5g/L soil drench were statistically the superior for the three Photosynthetic pigments, beside Biomagic 7.5g/L and Peptone 0.5g/L each sprayed solely especially with both chlorophyll B and carotenes contents. br Leaf chemical composition (nutritional status): br Obtained results declared that nutritional status of Washington navel orange trees (leaf macro - micro nutrient elements contents) responded obviously to the differential investigated bio - organic nutritive treatments. Anyhow, the highest values of leaf macro ((N, P, K, Ca and Mg) - micro (Fe, Mn and Zn) nutrient elements contents were significantly in concomitant to the Washington navel orange trees subjected to the (Biomagic 7.5g/L foliar spray + Hammer 1.5g/L soil drench) and (Peptone 0.5g/L foliar spray + Hammer 1.5g/L soil drench) followed by those sprayed with Biomagic solely. Meanwhile, other investigated treatments increased also leaf mineral contents but differences were less pronounced although with leaf P, Ca and Mg % variance than control didn’t reach level of significance. br V.II. Second experiment ”effect of some citrus rootstocks on young budded Washington navel orange transplants. br V.II.1. Morphological parameters: br V.II.1.A. Percentage of successful grafts: br In this regard success % of bud-take for shield budded Washington navel orange (scion) on three investigated citrus rootstocks (sour orange, Volkamer lemon and Balady lime) recorded after 3 months of budding was generally higher i.e., -gt; 93.0%. However, success % of grafts tended relatively to be lower on Balady lime rootstock (93.5 - 94.5%) than those on both Volkamer and sour orange (95.0 - 97.0%) and (96.5 - 96.75%) during 1st - 2nd seasons, respectively. br V. II. 1. B. Effect of rootstocks on scion growth measurements: br Data obtained during both 2008-09 - 2009-10 experimental seasons displayed obviously that four investigated growth measurements i.e., shoot (length - thickness), number of leaves per each and average leaf area of scion (Washington navel orange transplants) responded to the three evaluated citrus rootstocks. Anyhow, Volkamer lemon surpassed two other rootstocks for promoting the four investigated scion growth measurements. However, the response varied -#102;-#114;-#111;-#109; one growth parameter to another, whereas with shoot length and number of leaves the rate was more pronounced than that with two other parameters, particularly shoot thickness. Moreover, it could be safely concluded that the three evaluated citrus rootstocks could be arranged regarding their activities for promoting growth into the following descending order; a- Volkamer lemon, b- sour orange and c- Balady lime. br V.II.2. Effect on leaf chemical constituents of scion (Washington navel orange): br V.II.2.A.Leaf photosynthetic pigments (chlorophyll A, B and carotenes): br Data obtained during both experimental seasons displayed that leaf chlorophyll (A - B) and caroteniods contents of Washington navel orange transplants responded obviously to citrus rootstocks used. Hence, two conflicted trends were detected with two chlorophyll pigments (A - B) -#102;-#114;-#111;-#109; one hand and caroteniods substances -#102;-#114;-#111;-#109; the other. So, with chlorophyll A - B contents leaves of Washington navel orange on Balady lime rootstock were the richest, while the reverse was true with carotenoids level. On the other hand leaves of Washington navel orange transplants on either sour orange or Volkamer lemon had lower chlorophyll A - B content and didn’t significantly differ as compared each other. br V.II.2.B. Leaf mineral composition: br Data obtained during both 2008-09 - 2009-10 experimental seasons displayed that leaf mineral composition (N, P, K, Ca, Mg, Fe, Mn and Zn) contents of Washington navel orange transplants were generally higher on Volkamer lemon rootstock. The reverse was true with those budded on Balady lime rootstock. In addition, sour orange rootstock was intermediate in this concern. The rate of differences varied -#102;-#114;-#111;-#109; one nutrient element to another. Hence, differences in leaf N, Ca and Mg contents due to citrus rootstock used were significant with comparing Volkamer lemon to Balady lime. However, leaf P, K, Fe, Mn and Zn contents followed generally the same trend of response, but differences were less pronounced and didn’t reach level of significance as the influence of the three citrus rootstocks compared each other. br V.II. 3.Union zone anatomical study: br In this respect cross sections -#102;-#114;-#111;-#109; stock-scion union zone of shield budded grafts between Washington navel orange cv. (scion) and 3 citrus rootstocks namely a-sour orange, b-Volkamer lemon and c- Balady lime were anatomically studied through the microscopically examinations at 15, 30, 60,120and 240 days -#102;-#114;-#111;-#109; shield budding opration br The microscopical examinations of cross sections in union zone between scion (Washington navel orange) and three rootstocks (sour orange, Volkamer lemon and Balady lime) were dealing with some measurable anatomical features i.e., diameter of whole section, rootstock thickness, scion thickness, cortex thickness of both scion - rootstock, cambium and xylem thickness in rootstock, secondary cortex thickness, union zone thickness, number - thickness of vacuoles and presence of necrotic tissue - its thickness. br Microscopical examinations of union zone revealed obviously that tissues of both graft elements (scion - rootstock) i.e., diameter whole section, rootstock thickness, scion thickness, cortex thickness of both scion - rootstock, cambium - xylem tissues thickness in rootstock and thickness of both secondary cortex - union zone were gradually increased with aging . The rate of increase varied -#102;-#114;-#111;-#109; one anatomical feature to another and the rootstock played also its specific effect. Anyhow, the least rate was observed with cambium thickness particularly with grafts on Balady lime through all examination dates (after 15 up to 240 days) and at earlier dates (after 15, 30 and 60 days) with those on sour orange and Volkamer lemon .However, the rate of increase was relatively higher with thickness of both union zone and scion thickness on three rootstocks, taking into consideration that the increase took place earlier with sour orange than on two other rootstocks. On the other hand, number and thickness of vacuoles (air pockets) reduced by aging and completely disappeared after 60 days -#102;-#114;-#111;-#109; budding and this may explain the higher success % of budding on all 3 rootstocks, -#119;-#104;-#101;-#114;-#101; the union zone became anatomically about perfect after 60 days -#102;-#114;-#111;-#109; budding. br However, further anatomical studies are needed to throw some light on the wider thickness of union zone on sour orange than those on two other rootstocks. Besides, the appearance of narrower layer of necrotic tissues in union zone of grafts on Volkamer lemon rootstocks which may reflect some doubtfulness about the future of such rootstock.