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Abstract This investigation was carried out during two successive seasons 2018 and 2019 on semi-dry Al-Saidy (Sewy) date palm cv. uniform in vigor. Fifty-six “Saidy” palms were used in this experiment. The chosen palms were twenty years old and grown in private orchard located at Mochia village, El-Dakhla district New valley Governorate, where the soil texture is sandy, since water table depth is not less than two meters. The chosen palms were planted at 7 X 7 meters apart, good physical conditions and free of insects, damage and diseases. The palms was irrigated through groundwater using well water (EC = 650 ppm). Hand pollination of the selected palms was achieved. The overall aim of this study was investigate the response of Al-Saidy date palms, grown under grown under New Valley region, to replace the conventional mineral fertilizers of the three main cations (N, P and K) by using nano NPK fertilizers, and its effect on vegetative growth characteristics, mineral statues, yield and fruit physical and chemical properties. The present study included the follow fourteen treatments from NPK conventional and nano fertilizers arranged as follows: 1- Fertilization with NPK in form of conventional fertilizers. 2- Fertilization with conventional N fertilizer. 3- Fertilization with conventional P fertilizer. 4- Fertilization with conventional K fertilizer. 5- Fertilization with conventional N and P fertilizers. 6- Fertilization with conventional N and K fertilizers. 7- Fertilization with conventional P and K fertilizers. 8- Fertilization with nano N fertilizer. 9- Fertilization with nano P fertilizer. 10- Fertilization with nano K fertilizer. 11- Fertilization with nano N and P fertilizers. 12- Fertilization with nano N and K fertilizers. 13- Fertilization with nano P and K fertilizers. 14- Fertilization with nano N, P and K fertilizers Each treatment was replicated four times, one palm per each replicate. Then Fifty-six “Saidy” palms were used in the present study (14 treatments X four replicates). The experiment was arranged in a complete randomized block design (CRBD). During this experiment the following parameters were studied: The following vegetative growth parameters, leaves main pigments, mineral concentration in leaves, yield as well as physical and chemical properties of Al-Saidey fruits were measured or determined during the two experimental seasons (2017 and 2018). 15- Leaf morphology measurements: Morphology measurements of adult leaves have been studied. Morphological measurements included number of green leaves per palm, number of leaflets per adult leaves, leaflet area (cm2), leaf area (m2). The leaflet area (cm2) and leaf area (m2) has been measured by using adult leaves (using four adult leaves/palm one leaf from each geographic direction). The leaflet area (cm2) was determined by using Ahmed and Morsy (1999) equation (leaflet area = (W X L) x 0.67 + 10.29, in which W and L are the maximum width and length of leaflet). However, the leaf area (m2) has been calculated by multiplying the number of leaflets/leaf by the area of leaflet. Also, the number of spines / leaf as well as spine length (cm) were also determine. 16- Experimental design: Treatments were arranged in a complete randomized block design (CRBD). Each treatment was replicated four times and one palm per each was used. Different measurements and determinations: 1- Vegetative growth measurements: vegetative growth measurements included the number of green leaves per palm, number of leaflets per adult leaves, leaflet area (cm2) and leaf area (m2) were achieved. 2- Measurements of main pigments: Samples of six adult and fresh leaflets located at the middle part of the adult leaf (six month old leaves) were taken during 2ed week of August in both experimental seasons. Chlorophyll a, b and total chlorophyll as well as total carotenoids were calorimetrically determined at wave lengths of 662, 664 and 640 nm for chlorophylls a, chlorophyll b and total carotenoids respectively. Then the concentrations of these pigments were calculated using the following equations: Chl. a = (9.784 x E 662) – (0.99 x E 662) = mg / 100 g F.W. Chl. b = (21.426 x E 644) – (4.65 x E 644) = mg /100 g F.W. Total Carotenoids = (4.695 × E 440) – 0.268 (E 662 + E 644) = mg/100g F.W. where E = optical density at a given wavelength. Total chlorophyll was estimated by summation of chlorophyll a plus chlorophyll b (mg/ 100 g. F.W). 3- Leaves NPK determination: In early September, sixteen pinnae were selected from the middle area of adult leaves for each palm. The leaflet samples were washed and rinsed with distilled water. The leaflets were air-dried in oven at 70 °C for 48 hours. Then, it grounded and stored in small pockets prior analysis. o Nitrogen% was determined by modified micro kjeldahl method. o Phosphorus was determined by using colorimetric method, o Potassium was flam-photometrically determined. 4- Harvesting, Bunch weight and Yield (kg/palm): harvesting took place after rutab stage, under New Valley conditions on the last week of September during the two experimental seasons. Average bunch weight (kg) was recorded. The yield of each palm (kg/palm) was estimated by multiplying the number total of bunches per palm by average bunch weight (kg). 5- physical and chemical characteristics of fruits: samples of fifty date fruits from palm were picked randomly for estimation the following physical and chemical characteristics of fruit: 5-1: Measurement of fruits physical properties: • Average fruit weight and seed weight (g) • Average fruit dimensions (length and diameter (cm). • Pulp weight (g) and Seed weight (g). • Percentage flesh/seed ratio (weight/weight). 5-2: Determination of fruits chemical properties: 100 grams of fruit pulp was mixed with 100 ml distilled water and stand two hours. Then it minced will with electric blender for determination of the following chemical parameters: • The percentage of total soluble solids (T.S.S %). • Percentage of reducing sugar and total sugars. • Percentage of total acidity (expressed as grams malic acid). • Total soluble tannins. The most important results obtained during both seasons could be summarized as follows: 1- Vegetative growth characteristics: All studied vegetative growth characters. i.e. green leaves number/palm, number of leaflets/leaf, leaflet area and leaf area were gradually stimulated in response to replacing the conventional mineral NPK fertilizers by using NPK nano fertilizers individually or in possible combination. However, the best results of vegetative growth parameters were obtained due to treated Al-Saidy date palm with the N, P and K nano fertilizers in combination, these findings were true during the two experimental seasons. 2- Leaf main pigments contents: A promotion effect was observed on chlorophylls a & b and total chlorophylls as well as total carotenoids were obtained as a result of replacing NPK conventional fertilizers by the counterpart nano fertilizers, during the two experimental seasons. However, the palms received the three nano fertilizers in combination present the higher contents in all studied pigments during the two seasons. 3- Leaves NPK contents: the percentages of N, P, K, in adult leaves of Al-Saidy date palm significantly increased as a result of replacing the conventional N, P and K by counterpart N, P and K in form of nano fertilizers. Treated the palms with NPK nano fertilizers in combination present superiority than all the other individual or combination treatments with the tree elements. These data were true during the two experimental seasons. 4- Average weight of punch and Yield kg/palm: gradual promotion in Bunch weight (kg) per palm and yield (kg/palm) was observed as a result of replaced the conventional NPK fertilizers by counterpart nano NPK fertilizers. However, all NPK possible combination presents superior effect in these two parameters rather than the individual treatments. Replaced the three elements conventional mineral fertilizers by the three elements in form of nano fertilizers present the highest bunch weight and yield/palm during the two experimental seasons. then, we can concluded that, for improving Al-Saidy date palm yield and average bunch weight it was preferable to use the three main elements (N, P and K) in form of nano fertilizers. 1- Fruit Physical and Chemical properties: There was an obvious effect on physical and chemical properties of “Al-Saidy” date palm fruits due replaced the conventional fertilizers of the three main elements (NPK) by using NPK nano fertilizers. These were appeared in terms of increasing; fruit weight, fruit dimensions, pulp weight, TSS%, reducing sugars and total sugars%. Contrary, significant decrease in total acidity% and total soluble tannins% were observed. It’s worth to mentioned that, all possible combination between the three nano fertilizers present higher and significant values rather than the individual treatment of each element. Treating the palms with the mixture of the three nano fertilizers (N+P+K) produced the best results in this connection. It may be recommended by treating “Al-Saidy” date palm with NPK fertilizers in form of nano fertilizers for improving the physical and chemical properties of fruits. Conclusion: In order to improving the vegetative growth, mineral status of palms, yield and fruit physical and chemical properties of “Al-Saidy” date palms grown under the experimental region conditions (New Valley, Governorate, which the soil texture is sandy) and resembling conditions. It is strongly recommended to using the three main elements (N, P and K) in form of nano fertilizers, add as soil application. |