الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 169 |  |  |
| | | from | 169 | | |
Abstract
The present study was conducted during two successive seasons 2017 and 2018 on thirty offshoots derived Sakkoti date palms uniform in vigor, the palms were twenty years and grown in private orchard located at Edfu district, Aswan Governorate, where the soil texture is silty clay and well drained water since water table depth is not less than two meters. The chosen palms were irrigated through surface system using Nile water. The palms were planted at 8 X 8 meters apart, good physical conditions and free of insects, damage and diseases. Pollination was achieved by inserting five male strands into the female bunch using known high activity pollen source throughout 2-3 days after female spathe cracking. To prevent contamination of pollens, every bunch was bagged after inserting the mal strands by paper bags which were tied at the ends using a piece of cotton for aeration.
The overall aim of this experiment is to improve understanding of the influence of spraying different concentrations and frequencies of application of seaweed extract on some vegetative growth characteristics, leaf chemical composition, and yield as well as fruit physical and chemical characteristics of Sakkoti date palm grown under Aswan Governorate conditions.
The experiment includedthe follow ten treatments from different concentrations and frequencies of application of seaweed extract arranged as follows:
1- Control (untreated palms)
2- Spraying seaweed at 0.05% once at full blooming.
3- Spraying seaweed at 0.05% twice, at full blooming and just after fruit sett.
4- Spraying seaweed at 0.05% three times, at full blooming, just after fruit setting and one month later.
5- Spraying seaweed at 0.1% once at full blooming.
6- Spraying seaweed at 0.1% twice, at full blooming and just after fruit sett.
7- Spraying seaweed at 0.1% three times at full blooming, just after fruit setting and one month later.
8- Spraying seaweed at 0.2% once at full blooming.
9- Spraying seaweed at 0.2% twice, at full blooming and just after fruit sett.
10- Spraying seaweed at 0.2% three times at full blooming, just after fruit setting and one month later.
The experiment was arranged in a randomized complete block design (RCBD) with ten treatments, each one replicated three times, one palm per each.During booth experimental seasons, the following parameters were recorded:
1- Leaf morphology: Morphology measurements of leaves were studied on four full sized leaves/palm (one leaf at each side). Measurements included leaflet length and width of leaf (cm), leaflet area (cm2), total surface area of palm (m2) and number of spines per leaf as well as spine length (cm) were recorded. 2- Measurements of leaf main pigments: Samples of five mature and fresh pinnae from the six month old leaves were taken. The fresh pinnae were cut into small pieces and 0.5 g weight from each sample were taken for the determination of chlorophylls a, b and total chlorophyll as well as total carotenoids content using calorimetrically methods. 3- Determination of macro and micro-nutrients in leaves: A six months old labeled leaf per palm was removed (at the first week of August annually) the medium four pinnae were taken to determined macro and micro nutrients.
4- Yield and bunch weight: Bunches of Sakkoti date palm were picked at the optimum commercial harvesting time under Aswan region conditions, in the two experimental seasons. The yield of each palm and the average weigh of punch were recorded in terms of weight in kilograms.
Measurement of fruit physical properties: Sample of 20 fruits from each replicate was used for perform the following physical measurements:
• Average weight of fruit, seed weight and flesh weight (g).
• Fruit dimensions (length and diameter, cm).
• Percentage of seed and flesh weight were estimated.
• Edible (flesh weight) to non-edible portions (seed weight) was calculated (flesh/seed).
6: determination of fruit chemical properties: Sample of 100 gram of fruit flesh from each replicate was minced will with electric blender, after added 100 ml distillated water, for the following chemical parameters determination:
• Percentage of total soluble solids (T.S.S %) was determined by using hand refractometer.
• Percentage of total reducing sugar in the juice by using Lane and Eynone volumetric method.
• Percentage of total acidity (expressed as grams malic acid per 100 grams of flesh) by titration against 0.1 NaOH using phenolphthalein as an indicator.
The most important results obtained during both seasons could be summarized as follows:
1- Vegetative growth characteristics: All studied vegetative growth characters. i.e. leaf and leaflet length, leaf and leaflet area, and number of spines per leaf as well as spine length (cm) were gradually stimulated in response to spraying the palms once, twice and three times with seaweed extract at 0.05% to 0.2%, rather than control treatment. The best results were obtained due to spraying seaweed extract at higher concentration 0.2% three times. However, non-significant differences were recorded, neither between the two highest concentrations, nor between the frequencies.Leaf chemical contents: A promotion effect was observed on chlorophylls a & b, total chlorophylls and total carotenoids as well as percentages of N, P, K, Mg, as well as Zn and Fe (ppm) in the leaves when the seaweed extract sprayed once, twice and three times over the check treatments. Spraying the palms with seaweed at 0.1% or 0.2% two or three times gave the maximum values. However, non-significant differences were recorded between the palms received seaweed at 0.1% and those resaved 0.2%. Therefore, from economical point of view, spraying seaweed extract at 0.1% two times was improved to be very effective in this respect.Average weight of punch and Yield kg/palm: Increasing concentrations of seaweed extract from 0.05% to 0.2% had a considerable promotion on the weight of bunches and yield/palm (kg). A remarkable promotion in both of bunch weigh and yield/palm were observed, rather than control treatment. However, non-significant differences were observed neither between the higher two concentration nor between the higher two frequencies. For improving Sakkoti date palm yield and bunches weight it was preferable to use the seaweed extract two times at 0.1% from economical point view. 5- Fruit Physical and Chemical properties: There was an obvious on physical and chemical characteristics of Sakkoti date palm fruits due to spraying seaweed extract over the check treatment. This was appeared in terms of increasing fruit weight and dimensions, flesh weight%, TSS%, reducing sugars and non-reducing sugars%. On the other hand significant decrease in total acidity%, soluble tannins% and crude fibers% were observed. Treating the palms with seaweed extract at 0.2% three times gave the best results in this connection. However non-significant differences were observed neither between the two higher concentrations nor between the two higher frequencies, during the two experimental seasons.