الفهرس 
INTRODUCTION
Effect of potassium silicate sprayingOnly 14 pages are availabe for public view
 |  | from | 140 |  |  |
| | | from | 140 | | |
Abstract
This investigation was conducted in date palm Research Farm in Agricultural Research Station located at El-Kharga Oasis, New Valley Governorate, during the three successive seasons of 2013, 2014 and 2015 on thirty years old Saidy date palms cv. (as semi dry date palm cv.). The laboratory work of this study was conducted in Regional Agricultural Research Station of the New Valley. This study included three experiments. Thirty five healthy date palms were chosen and devoted for achieving these experiments. I- The first experiment: The objective of this experiment was examining the effect of spraying potassium silicate on fruiting of date palm Saidy cultivar during 2013, 2014 and 2015 seasons. Fifteen palms in the same age and uniform in growth and bearing of approximately the same number of spathes were selected. 1- Spraying water without potassium silicate (control). 2- 2.5 cm potassium silicate/ 1 L water. 3- 5 cm potassium silicate / 1 L water. 4- 10 cm potassium silicate/1 L water. 5- 20 cm potassium silicate/1 L water The previous spraying was five treatments with 3 replications, one palm per each. Spraying times was mid of May and until the first July. An average of every fifteen days (4 spraying). II- The second experiment: The objective of this experiment was examining the effect of some pollen grain sources on fruiting of date palm Saidy cultivar during 2013, 2014 and 2015 seasons. The experiment palms were chosen healthy, nearly uniform in vigour as possible and subjected to the some cultural practices commonly adopted in the orchard. The number of bunches per palm was adjusted to (10) bunches nearly equal in size by removing excess number from latest and earliest small ones. Six sources of pollen grains were used for this study. Male palms are grown at three different regions as follows: Assiut, El-Kharga and El-Dakhla. The male spathes were collected once spath cracking and strands were separated individually and dried at room temperature to avoid high moisture. Pollination treatments were hand pollination by inserting 7-10 strands/bunch. Pollinated spathes were immediately covered with paper bags to protect them from any foreign pollen grains and were released from the bags after 30 days from pollination time. Six female palms were selected and divided into 6 treatments in ten replicates, bunch each. Treatments were applied on the same palm and arranged in randomized complete block design. III- The third experiment: This study was carried out on nine palms with uniform vigour and in good physical condition, free of insect damage and diseases. The numbers of spathes per palm were adjusted to ten by removing excess earliest, latest and smallest. The retained bunches were thinned to a constant number of strands. The involved palm trees received the same horticulture practices. Nine pollination and fruit thinning treatments were arranged as follows: 1- Hand pollination by inserting 7-10 strands/bunch (T1). 2- Dusting mixed pollen grains at 1 unit of pollen to 1 unit starch (50% active ingredients) on a volume basis (T2). 3- Dusting mixed pollen grains at 1 unit of pollen to 3 units starch (25% active ingredients) on a volume basis (T3). 4- Dusting mixed pollen grains at 1 unit of pollen to 5 units starch (17% active ingredients) on a volume basis (T4). 5- Dusting mixed pollen grains at 1 unit of pollen to 7 units starch (12.5% active ingredients) on a volume basis (T5). 6- Dusting mixed pollen grains at 1 unit of pollen to 9 units starch (10% active ingredients) on a volume basis (T6). 7- Thinning by removing 15% of the fruits per strands (T7). 8- Thinning by removing 30% of the fruits per strands (T8). 9- Thinning by removing 45% of the fruits per strands (T9). Pollination was uniformed in respect of source date and method to avoid residues of metaxenia, as well as fruit thinning treatments were done after fruit set and applied on the same palm. The experiment was arranged in a complete randomized block design including nine treatments with ten replications, bunch each. All bunches were harvested at tamr stage (last week of September) ultimate fruit retention and fruit weight/bunch (kg) were estimated. Samples of 50 fruits were picked at random from each bunch for the determination of some physical and chemical fruit properties. 1- Yield and its components (fruit retention percentage, bunch weight and yield/palm). 2- Fruit quality: - Physical characteristics. - Chemical characteristics. The data obtained during the three studied seasons could be summarized under the following main items: A- The First Experiment: Effect of potassium silicate spraying 1- Yield and its components: Bunch weight and yield/palm significantly increased due to spray potassium silicate compared to untreated one. The promotion of bunch weight and yield/palm were associated with increasing the spraying solution. In addition, there was insignificant difference due to increase the potassium silicate from 10 to 20 ml/L. The heaviest bunch (12.23 & 72.37 kg) and yield/palm (123.10 & 124.13 kg as an. av. of three studied seasons) were recorded on bunches that sprayed with potassium silicate (10 or 20 ml/L), respectively. 2- Fruit quality 2-1. Physical characteristics: Spraying Saidy date bunches with potassium silicate significantly increased the fruit weight, flesh percentage, fruit length and fruit moisture percentage compared to control. The promotions of these traits were associated with increasing of the potassium silicate concentration spraying. Spraying 20 ml/L potassium silicate gave the highest of these fruit traits during the three studied seasons. Hence, the heaviest fruit weight (10.33 & 10.38 g), flesh percentage (88.01 & 88.10%), fruit length (3.62 & 3.63 cm) and fruit moisture percentage (15.57 & 15.61%) as an av. of three studied seasons), respectively. Whereas the lowest values of fruit weight was (8.45 g), flesh percentage (85.75%), fruit length (3.50 cm) and fruit moisture percentage (14.13% as an av. three studied seasons) were noticed with unsprayed ones, respectively. Then the increment percentage due to treatments of fruit weight were (9.34, 12.43, 22.25 & 22.84%), flesh percentage (1.35, 1.64, 2.65 & 2.74%), length (2.38, 2.57, 3.43 & 3.71%), and fruit moisture percentage (3.82, 4.47, 10.19 & 10.47%) due to spraying potassium silicate at 2.5, 5.0, 10.0 and 20.0 ml/L over untreated ones as. an. av. the three studied seasons, respectively. No significant differences were observed in these traits due to spray bunches with potassium silicate at 10 or 20 ml/L. 2-2. Chemical constituents of fruits: Spraying Saidy date bunches with potassium silicate significantly improved the dates chemical constituents in terms of increasing the total soluble solids, sugar contents and decreasing the total acidity and total soluble tannins percentages compared to untreated ones (control). Spraying potassium silicate at 10 ml or 20 ml/L four times gave the highest total soluble solids and sugar contents of fruits during the three studied seasons. No significant differences were recorded in these parameters due to spray bunches of Saidy date palm with either 10 or 20 ml/L potassium silicate. Whereas, the least values of TSS, total sugars, reducing sugars and non reducing sugars contents were recorded due to unsprayed palms (control). B- The Second Experiment: Effect of male type on fruiting: 1- Yield: Fruit retention and fruit weight per bunch were significantly affected due to use different pollinizers. Pollination with pollen grains either the El-Kharga 1 or El-Kharga 2 male palm significantly increased the fruit retention percentage and significantly decreased the fruit weight per bunch of Saidy date compared to those pollinated with pollen grains from Assiut or El-Dakhla. The highest fruit retention was obtained due to pollinate with pollen grains from El-Kharga, whereas, the lowest values were recorded due to use pollen grains from Assiut. No significant differences on the fruit retention due to pollinate with pollen grains from Assiut or El-Dakhla. Moreover, no significant differences in the fruit weight per bunch due to use pollen grains of Assiut 1 or Assiut 2, El-Dakhla 1 or El-Dakhla 2 as well as El-Kharga 1 or El-Kharga 2. In general, data clearly indicated that pollen grains of Assiut or El-Dakhla are the best for pollinate Saidy date palm which they gave the highest bunch weight compared to use pollen grains from El-Kharga. 2- Fruit quality 2.1- Physical fruit properties: Use pollen grains of either Assiut or El-Dakhla significantly increased the fruit weight and fruit dimension, as well as, flesh weight and fruit moisture percentages compared to use pollen grains of El-Kharga male palm. The heaviest fruit weight and highest flesh percentage were recorded due to pollinate with pollen grains of Assiut 1 male type. The vice versa, the lightest fruit and lowest flesh percentage were obtained due to pollen grains of El-Kharga 2 male type. No significant differences were found due to pollinate with pollen of Assiut 1 or Assiut 2, as well as El-Dakhla 1 or El-Dakhla 2, also El-Kharga 1 or El-Kharga 2 pollen grains male type. Longest and widest fruits were recorded due to use pollen grains of Assiut 1 male type. The vice versa, the shortest and thinest ones were obtained due to pollen grains of El-Kharga 1 male type. The maximum fruit moisture percentage was found due to pollinate with pollen grains of Assiut 1 male type, whereas, the minimum values were recorded due to use pollen grains of El-Kharga 2 male type. No significant differences were found due to pollinate with pollen of Assiut 1 or Assiut 2, El-Dakhla 1 or El-Dakhla 2 as well as, El-Kharga 1 or El-Kharga 2 male types. 2.2- Chemical fruit constituents: Pollination by Assiut or El-Dakhla significantly improved the dates chemical constituents in terms of increasing the total soluble solids, total and reducing sugars and decreasing the total acidity and total soluble tannin percentages compared to pollination with pollen grains from El-Kharga male type. The highest values of total soluble solids and sugar contents were significantly obtained in descending order due to pollination by pollen grains of El-Dakhla 1, El-Dakhla 2, Assiut 1 or Assiut 2, respectively. The vice versa, the lowest values were obtained due to pollination with pollen grains of El-Kharga 2 male type. On the other hand, pollination with pollen grains of El-Kharga male type significantly increased the titratable acidity parentage and total soluble tannin percentage compared to pollination with pollen grains from Assiut or El-Dakhla male types. The highest titratable acidity and tannin percentages were obtained due to pollination with pollen grains from El-Kharga, whereas the least values were obtained due to use pollen grains from El-Dakhla male type. No significant differences were found due to pollination with pollen grains from Assiut or El-Dakhla male types. In general data showed that pollen grains from Assiut or El-Dakhla are the best for pollination Saidy date palm which they gave best fruit quality compared to use pollen grains from El-Kharga male palm. C- The Third Experiment: Effect of pollination and fruit thinning treatments: 1- Yield: Fruit retention percentage and fruit weight/bunch were significantly decreased due to pollinating by dusting with a mixture of pollen grain with starch at 1 pollen to 5, 7 or 9 starch (17, 12.5 or 10% pollen) as well as doing fruit thinning compared with the traditional pollination gave the same effect. No significant differences in fruit retention and fruit weight/ bunch were noticed due to dust pollen powder at 1 pollen to 1 or 3 starch (50 or 25% active ingredients on volume basis). Also, no significant differences in these traits were found due to dusting by 17% pollen grains and fruit thinning by removing 15% of fruits, as well as dusting by 12.5% pollen grains and fruit thinning by removing 30% of fruits. The reduction on fruit weight/bunch was associated with decreasing the pollen grain percentage from 50 to 10% as well as fruit thinning from 15 to 45% of fruit set. 2- Fruit quality: 2.1- Physical characteristics: There was an improvement of the fruit physical quality in terms of increasing the fruit weight, dimensions and fruit pulp percentage and decreasing moisture content due to pollination with dusting methods or fruit thinning compared to the traditional pollination (control). The improving of these traits was associated with the decrease of the used pollen grains concentration from 25-10% as well as retained fruits from 85 to 55% of setting fruits. The heaviest fruits were detected on palms pollinated with pollen grain concentration at 10% of dusting powder, as well as removing 45% of setting fruit. No significant differences in fruit weight, dimensions, fruit pulp % and moisture content were observed due to using dusting of pollen grains at 10 or 12.5% as well as fruit thinning by removing 30 to 45% of setting fruits. 2.2 Chemical characteristics: Pollination by pollen grains dusting or fruit thinning were significantly improved the fruit chemical constituents in terms of increasing the soluble solids and sugar contents and decreasing the total acidity and tannins percentage compared to pollination by traditional pollination. The improvement of these fruit traits was associated with the reduction of pollen grain concentration from 25 to 10% as well as retained fruits from 85-55% of setting fruits or pollen powder dusting at 10% pollen as well as removing 45% of setting fruit gave the maximum values of soluble solids and sugar contents, whereas, using the traditional pollination gave the minimum values. No significant difference in fruit chemical properties were observed due to use of either dusting pollen at 10-12.5% or removing 30-45% of setting fruits. Conclusion On account of the obtained results one can confirm: -Spraying bunches of Saidy date palm after two month of pollination with 10 m/L potassium silicate four times every two weeks. - Pollen grains of Assiut or El-Dakhla were the best for pollination the Saidy date palm under El-Kharga condition. - Pollination by 12.5% pollen grains powered or fruit thinning by removing 30% fruit setting. - Dusting pollen grains powder at 12.5% play a combined effect as mechanical pollination and fruit thinning.