الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
This study was initiated in an orchard of Sewy date palm situated at El- Farafrah Oasis, New Valley Governorate during 2006 and 2007 seasons on 14 years old of conventionally propagated by off shoots Sewy date palms. Palms were grown in sandy soil and planted at 7 X7 meters apart. The number of female spathes per each palm was adjusted to ten spathes. the leaf bunch ratio was maintained at 7 : 1.
Generally , hand pollination of all the selected palms was achieved by inserting ten male strands into the centre of female bunch using different sources of pollen grains (from vigour, intermediate vigour, and weak males) throughout different dates after spathe cracking during various times of one day. To prevent contamination of pollens, every bunch was bagged after inserting the male strands by paper bags which was tied at the end using piece of cotton for aeration. The bags were shaken lightly to ensure pollen distribution and were removed after four weeks.
The experiment included three factors ( A & B & C) . The first factor (A) consisted from three treatments of male vigour namely a1) Vigour males ( had spathes with higher weight and dimensions, longer strands as well as greater number of flowers / strand and amount of pollen per spathe, a2) Intermediate vigor males (had medium values of spathes morphological characters and medium amount of pollens per spathe and a3) Weak males (had lower values of spathes morphological characters and small amount of pollens per spathe.
The second factor (B) involved five treatments from dates of pollination after spathe cracking namely b1) two days , b2) four days, b3) six days, b4) eight days and b5) ten days after spathe cracking. The third factor (C) consisted from three treatments from day time of pollination i.e. early morning ( 6.30- 7.30 am ); afternoon ( 12- 1.0 pm) and before sunset ( 4.30 – 5.30 pm)
Therefore, the experiment included 45 different pollination treatments ( 3 male vigor treatments X 5 dates of pollination after spathe cracking X 3 day time pollination treatments)
Each treatment was represented by three Sewy date palms. Each replicate represented by one palm.
The experiment was set up in split split-plot arrangement of completely randomized block design. Male vigor, dates of pollination and day time of pollination stood up for main, sub-plots and sub sub-plots , respectively.
For elucidating the various effects of male vigour as well as date and day time of hand pollination on fruiting of female Sewy date palms , the following parameters wee measured.
1-Morphological characters of male spathe and pollens, amount of pollens / spathe as well as percentages of stainability and germination of pollens of the vigour , intermediate vigour and weak males of Sewy date palms.
2-The yield / palm (kg)
3-Average bunch weight (kg)
4-Averagesa weight (g) , length and width (cm) of date
5-Percentage of pulp.
6- Pulp / seed in the date.
7-Percentages of total soluble solids, total reducing and non- reducing sugars in the pulp.
8-Percentages of total acidity, total soluble tannins and crude fibres.
9-Percentage of total proteins in the dates.
10-Percentages of N, P, K, Ca and Mg in the dates.
The nearly same obtained results in both seasons could be summarized under the following main items.
1-Characteristics of male spathes and pollens in vigour, intermediate vigour and weak Sewy date palm males.
Morphological characters of male spathes namely weight, length, width and colour of spathes, number of strands / spathe, strand length and number of flowers / strand and pollen amount / spathe were greatly varied among vigour, intermediate vigour and weak of Sewy date palm males. However, pollen grains obtained from spathes of vigour, intermediate vigour and weak males had the same percentages of stainability and germination. The maximum values were recorded on vigour Sewy date palm males. Weak males had the lowest values.
2-Yield per palm:
Yield per palm of Sewy date palms was slightly affected by varying, male vigour. The greatest yield was recorded when pollination was conducted by using pollen grains obtained from vigour , intermediate vigour and weak males, in descending order.
Pollination at the length of time which female flowers of Sewy date palms remain receptive to fertilization had an outstanding effect on the yield. Delaying dates of pollination after spathe cracking from the second to the tenth day caused a gradual reduction on the yield . Carrying out pollination beyond the sixth and the tenth days after spathe cracking caused a major decline on the yield. Similar yield was recorded when pollination was carried out either at the second or at the fourth day after spathe cracking . The maximum and minimum yield were recorded when palms were pollinated at the second and the tenth days, respectively.
Yield was greatly affected by day time of pollination. Delaying day time of pollination from early morning to before sunset was followed by a gradual promotion on the yield. Hand pollination before sunset and at early morning gave the maximum and minimum yields, respectively.
Selecting vigour palms for obtaining pollen grains and pollinating female palms at the second day of spathe splitting at the day time before sunset gave the best results with regard to yield.
3- Average bunch weight:
It was unaffected by varying male vigour . Pollination at the period during which the flowers remain receptive to fertilization had an obvious promoting effect on bunch weight. Delaying pollination date from the second to the fourth day of spathe splitting had a slight reduction on bunch weight. There was a gradual reduction on bunch weight with delaying dates of pollination from the second to the tenth day of spathe opening. Delaying pollination date from four to ten days after spathe splitting resulted in great reduction on bunch weight. The maximum and minimum bunch weight were recorded on palms pollinated at the second and tenth day of spathe opening, respectively.
Pollination before sunset, afternoon and early morning, in descending order increased bunch weight.
The heaviest bunches were borne on palms pollinated at the second day of spathe cracking at day time namely before sunset with pollens obtained from vigour males. Selecting weak males for obtaining pollen grains and pollinating the palms at ten days after spathe cracking at the day time of early morning gave unacceptable results with regard to bunch weight.
4-Physical and chemical characters of the fruits:
Physical and chemical characters of Sewy dates did not affect with varying male vigour.
Delaying date of pollination after spathe cracking from the second to the tenth day of spathe splitting was followed by a gradual promotion on fruit quality of Sewy date palms in terms of increasing fruit weight and dimensions (length and width) , percentage of pulp, pulp /seed, total soluble solids %, total and reducing sugars % and total proteins % and in decreasing total acidity %, total soluble tannins % and crude fibres %. All physical and chemical characters of Sewy date fruits were similar if pollination took place either at the second to the fourth day of female spathe cracking. Delaying pollination from the fourth to the tenth day of spathe splitting resulted in considerable promotion on fruit quality. Pollination at ten days after spathe cracking gave the best results with regard to fruit quality. Unfavourable effects on fruit quality were recorded on bunches harvested from palms pollinated at two days after spathe cracking. Date of pollination had no effect on non reducing sugars in the pulp.
Advancing day time of pollination materially enhanced fruit quality. Hand pollination at the time of early morning resulted in material promotion on fruit quality. Unfavourable effects on fruit quality were recorded on bunches picked from palms pollinated at the time before sunset.
5-Percentages of N, P, K , Ca and Mg in the pulp:
Male vigour of Sewy date palm failed to show measurable effects on percentages of N, P, K, Ca and Mg in the pulp.
Delaying hand pollination date after spathe cracking was followed by a gradual promotion on percentages of N, P, K, Ca and Mg in the pulp. Delaying date of pollination from the second to the fourth day of spathe splitting resulted in material promotion on all nutrients except both Ca and Mg which tended to increase slightly. Pollination at the tenth day of spathe cracking maximized these essential nutrients in the pulp. The lowest values were recorded when pollination was conducted at two days after spathe cracking.
Day time of pollination had an obvious effect on percentages of P and K and had no effect on percentages of N, Ca and Mg in the pulp. The promotion on these nutrients was associated with advancing day time of pollination from sunset to early morning. Hand pollination at the time of early morning maximized these nutrients. However, the lowest values were recorded when pollination was conducted before sunset.
CONCLUSION:
According to the obtained data , it is concluded that:
1-Male vigour of Sewy date palms had no obvious effect on fruiting of female Sewy date palms.
2-The optimum length of time during which female flowers of Sewy date palms remain receptive to fertilization was four days after spathe cracking.
3-Hand pollination of female Sewy date palms beyond six to ten days after spathe cracking caused a great decline on the production of palms.
4-The best day times for pollination of Sewy date palms were before sunset followed by the time of afternoon.
5-For promoting yield and fruit quality of Sewy date palms grown under El-Farafrah conditions, New Valley Governorate, palms should be manually pollinated with pollen grains obtained from Sewy males at the second to the fourth day of spathe splitting at the day time of sunset or afternoon.