الفهرس 
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Abstract
VI. SUMMARY
The present experiment was carried out during the summer seasons of 2014 and 2016 at the Experimental Farm of Vegetable Crops Department, Faculty of Agriculture, Assiut University, Egypt. Seedlings that were planted in the 2015 season failed to complete their germination and subsequent growth. Therefore we will only mention the results of the 2014 and 2016 sowing seasons.
The experimental site is located at 270 18’ latitude and 310 18’ longitudes and at an elevation of 70 meters above sea level. The average annual rainfall is 13 mm (Ashour et al., 2015). The highest absolute minimum and highest absolute maximum annual temperatures are of 0.4oC and 47.6oC, respectively. The soil texture of the experimental site was clay with a pH average of 7.65. Three irrigation intervals and three eggplant genotypes were used. The irrigation treatments consisted of three irrigation periods: commercial irrigation treatment (W1, irrigated every 10 days), (W 2, irrigated every 20 days) and (W 3, irrigated every 30 days). The three genotypes used in the experiment were: Alabaster F1, Hanen F1 and Classic F1.
The three irrigation intervals and the three hybrids of eggplants were used in this experiment to investigate the effects of irrigation intervals and eggplant genotypes on growth, yield, and quality of eggplant crops under Assiut conditions.
The obtained results could be summarized as follows:
The effects of the three drought intervals on average plant height were significant in the second season only. Eggplant plants irrigated every 20 or 30 days gave significantly the lowest plant height values. However, plants that were irrigated every 10 days significantly gave the tallest plants. The average plant height was significantly affected by eggplant genotypes as an average all over the three irrigation intervals. Hanen genotype significantly gave the tallest plants in the first (104.44 cm) and the second seasons (93.03 cm). The shortest plants were obtained in Classic F1 genotype (Rome) in the first (66.82 cm) and second season (71.44 cm).
1- The effects of the three drought periods on the average number of lateral branches per plant were significant in the first season only. It is confusing that the longest irrigation period (every 30 days) significantly gave the highest average number of branches per plant (39.61). In the second season, the control treatment gave the highest average number of lateral branches per plant. However, the difference between the three irrigation treatments did not reach the level of statistical significance. Hanen F1 significantly gave the highest average number of lateral branches per plant while Classic F1 (Rome) gave the lowest numbers in both seasons.
2- The highest significant values of average stem diameter were recorded from the 10-day irrigation intervals in the second season only. However, the lowest average stem diameter values were recorded in the plots irrigated at 20- and 30-day intervals, respectively. The highest average stem diameter was obtained with Hanen F1 genotype in both seasons. The lowest values, however, occurred with genotype Classic F1 in both seasons.
3- The commercial irrigation treatment (10 days) significantly produced the highest total fruit yield per plot in the first (73.58 kg) and the second season (43.53kg). On the other hand, irrigation every 20 and 30 days in the first season and every 30 days in the second season significantly produced the lowest total fruit weight. Regard to genotypes effect, the three hybrids Hanen, Alabaster, and Classic F1 gave nonsignificant responses to drought stress regarding the total yield in the two summer seasons of 2014 and 2016.
4- The effect of the irrigation interval on the tested three genotypes showed no significant differences among the three irrigation intervals on the average fruit weight in the two summer seasons. Classic F1 hybrid gave the highest value of average fruit weight followed by Hanen F1 and Alabaster f1, with nonsignificant differences between the two hybrids.
5- In the first season, irrigation periods did not significantly affect the monthly average fruit yield at all sampling dates except in June and August. In the second season, however, the last three sampling dates during the hottest months of the experiment (July, August and September) showed a significantly different monthly average fruit yield. The control treatment and the middle irrigation interval (every 20 days) increased the monthly average fruit yield in both seasons except during August sampling date. Data of average monthly fruit yield was affected by the date of fruit picking and it represents in a bell-shaped curve. In both seasons, September sampling date produced the heaviest average fruit weight (curve peak) as compared to May picking date that produced the lowest average fruit yield.
6- Data shows that the three water stress intervals had insignificant effect on the early yield of eggplant in both seasons. In the second season, Rome F1 gave the highest early yield while the white genotype (Alabaster F1) significantly produced the lowest early yield. Same trend was recorded in the first season, but the early yield values didn’t reach the significant level.
7- The unstressed (control) treatment gave significantly the highest average fruit number per plot in the first (669.9) and the second (313.4) summer seasons. Hanen and Alabaster genotypes produced the highest fruit numbers (719.3 and 653.3, respectively). As can be expected, Classic F1 (Rome) gave significantly the lowest number of fruits.
8- In the first season, the recommended irrigation period for Assiut province (every 10 days) significantly produced the tallest fruit compared to the other two irrigation regimes. The medium irrigation stress treatment (W2) ranked the second with significant difference between the (W3) treatments. The prolonged repetitive severe stress treatment (W3) significantly gave the lowest fruit length in the first season. Hanen F1 hybrid significantly produced the tallest average fruit length in the first (19cm) and second (16.26 cm) seasons. As expected, Rome F1 genotype gave significantly the shortest average fruit length in the first (11.07cm) and second (12.00 cm) seasons.
9- The highest significant values of the whole plant fresh weight were recorded in the control treatment (irrigated every 10 days) during both seasons. The results of the present study obviously indicate that Hanen F1 genotype is more tolerant to drought while Classic F1 is found to be drought sensitive and needs further improvement for its tolerance to abiotic stress.
10- The 10-day irrigation treatment (control) significantly recorded the highest plant dry weight in the first (300.41g) and second (201.04g) seasons. The severe irrigation treatment (30 days) produced the lowest average dry weight per plot in the first (192.38g) and second (121.67g) seasons. Hanen F1signficantly produced the highest plant dry weight, whereas Classic F1 significantly gave the lowest whole plant dry weight in both seasons. Alabaster F1 ranked the second after Hanen F1 in the first season while both Hanen F1 and Alabaster F1 gave the highest dry weight in the second season.
11- Results of the two seasons showed that the highest proline content was recorded in the longest drought interval (30 days), while the lowest concentration was found in shortest drought period (10 days). The highest levels of proline were detected with the prolonged repetitive severe stress treatment (W3) followed by the long-term repetitive (W2) then W1 treatment. Rome F1 genotype significantly gave the highest proline concentration in the first (2.89 mg/g dry weight) and second (5.77 mg/g dry weight) seasons. Indeed, our findings revealed that proline accumulation increase greatly within the tolerant genotype compared to the sensitive genotype. The sensitive genotype Hanen F1 gave the lowest proline concentrations in the first season, whereas Alabaster F1 significantly produced the lowest proline concentration in the second seasons.
12- The irrigation intervals had non-significant effect on eggplant chlorophyll concentration. Regarding the effect of the three hybrids, the differences in chlorophyll concentrations did not reach the statistical significance. However, Hanen, followed by Rome F1, gave the highest chlorophyll concentration while Alabaster F1 gave the lowest concentration.
13- Plant height was significantly correlated with branch numbers, plant dry weight, proline percentage in the first season, and with branch numbers and plant dry weight only in the second season. Total fruit number was significantly correlated with plant height, branch numbers, plant dry weight, and proline content in both seasons. Total fruit yield was significantly correlated with average fruit weight and plant dry weight in both seasons.