الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
Results could be summarized as follows:
1. First experiment (Plastic house experiment)
1.1 Effect of magnetic irrigation water and NPK rates on vegetative growth, yield and its components and fruit quality of sweet pepper.
This experiment was carried out under plastic house conditions during winter seasons of 2016-2017 and 2017-2018 at protective cultivation directory, Ministry of agriculture in Dokki, Giza Governorate and Handling Laboratory of Vegetable Crops Research Department. Horticulture Research Institute at Giza Governorate, to study the effect of magnetic irrigation water and NPK rates on vegetative growth, yield and its components and fruit quality of sweet pepper. The experimental soil was loamy. Seeds of sweet pepper (Capsicum annuum L.) Lareka F1 hybrid were sown at the nursery on 11th and 13th of September in 2016 and 2017 seasons, respectively, and seedlings were transplanted on 25th of October in both seasons. The plastic house was 60 m long and 9 m wide (540 m2) and divided into five beds, each 1 m wide and 60 m long. The experiment occupied three beds. Seedlings were planted on the two sides of each bed and 50 cm apart.
The treatments were as follows:
5. Control (100 % of NPK + Non-Magnetic Water.).
6. 50 % NPK+ Magnetic Water.
7. 75 % NPK+ Magnetic Water.
8. 100 % NPK+ Magnetic Water.
The previous treatments were arranged in a complete randomized block design with three replicates. The area of each plot was 10 m2 with 40 plants. Each replicate consisted of one plot.
The obtained results are summarized as follows:
1- Using magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK significantly increased plant height, number of leaves per plant and leaf area over control treatment.
2- The highest values of chlorophyll content in sweet pepper leaves were recorded for magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK.
3- Control treatment recorded the lowest values of plant vegetative growth (plant height, number of leaves per plant and leaf area) and leaves chlorophyll reading.
Yield and its components:
Fruit quality
Physical properties
1. Using magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK increased fruit weight, fruit length and fruit diameter over control.
2. The highest values of flesh thickness of fruit were obtained from plants irrigated with magnetic irrigation water +75% NPK.
3. The highest values of firmness of fruit were obtained from plants irrigated with magnetic irrigation water +75% NPK followed by magnetic irrigation water +50% NPK.
Chemical properties
1. The highest values of dry matter content of fruit were obtained from plants irrigated with magnetic irrigation water +75% NPK.
2. There were no significant differences between magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK. in fruit diameter.
3. The highest values of TSS content of fruit were obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK with no differences between them.
4. The highest values of L ascorbic acid content of fruit were obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK with no significant differences between them.
5. There were no significant differences among all treatments and control in carotenoids content of fruits.
2. Second experiment
2.1. Effect of magnetic irrigation water and NPK rates on storability of sweet pepper fruits.
Sweet pepper fruits which obtained from the previous experiments were harvested at 3/4 yellow color stage on January 14th and 16th in the first and second seasons, respectively; then transported to the laboratory of Handling of Vegetable Crops Department, at Giza, that were sound, healthy fruits, and free from blemishes were selected for storage experiment and stored at 10ºC and 90-95% relative humidity for 28 days.
The obtained results could be summarized as follows:
1. Weight loss percentage of sweet pepper fruits was increased with the prolongation of storage periods or storage period plus shelf life.
2. Sweet pepper fruits obtained from plants obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK had the lowest weight loss percentage during all over the storage periods or storage periods plus shelf life.
3. Decay percentage was significantly increased with the prolongation of storage periods or storage periods plus shelf life.
4. All preharvest treatments were significant in reducing decay percentage during all storage periods or shelf life compared with control.
5. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK exhibited significant reduction in the percentage of decay during storage periods or storage periods plus shelf life.
6. There was significant reduction in general appearance with the prolongation of storage periods or storage periods plus shelf life.
7. Magnetic irrigation water +75% NPK was the most effective treatment in maintaining fruits general appearance. Fruits of this treatment did not exhibit any change in their appearance till 14 th day at 10°C +2 days at 20°C and gave a product with good appearance after 28 days of storage at 10°C + 2 days at 20°C.
8. General appearance of fruits obtained from plants irrigated with magnetic irrigation water +75% NPK gave good appearance after 28 days at 10°C + 2 days at 20°C.
9. There was a significant decrease in L value of sweet pepper fruits with increasing storage periods plus shelf life for all treatments and control, showing darker fruit (low L value).
10. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK were significantly lighter in color (high L value) than other treatments during storage periods or storage periods plus shelf life.
11. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +100% NPK followed by control had darker color (low L value) during storage periods or storage periods plus shelf life.
12. There was significant increase in decay score with the prolongation of storage period.
13. here was a significant reduction in fruit firmness by prolongation of storage periods or storage periods plus shelf life.
14. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +75% NPK were the most effective treatment in reducing the loss of fruit firmness during storage periods or storage periods plus shelf life.
15. The lowest value of fruit firmness resulted from untreated control during storage periods plus shelf life.
16. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +75% NPK had significantly higher TSS % than all treatments during storage periods plus shelf life conditions.
17. Ascorbic acid content of sweet pepper fruits was decreased with the prolongation of storage periods or storage periods plus shelf life.
18. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK were the most effective treatments in maintaining L ascorbic acid content during storage periods or storage periods plus shelf life.
19. The lowest values of L ascorbic acid content resulted from untreated control during storage periods plus shelf life.
20. Total carotenoids content of fruits was significantly increased during storage periods or storage periods plus shelf life.
21. Sweet pepper fruits obtained from plants irrigated with magnetic irrigation water +100% NPK or control had the highest values of carotenoids content during storage periods shelf life.
22. Application of different rates of NPK + irrigation with magnetic water maintaining the TSS, ascorbic acid and total carotenoid contents when compared with control treatment.
3.Third experiment
3.1. Effect of some postharvest treatments on quality attributes of sweet pepper fruits during storage and shelf life conditions
Sweet pepper fruits were harvested at 3/4 yellow color stage on February 27th and 29th in the first and second seasons, respectively; then transported to the laboratory of Handling of Vegetable Crops Department, at Giza. Fruits uniform in size (about 280 ± 10gm each fruit) and color, with short calyx (1 cm long) that were sound, healthy and free from blemishes were selected for postharvest experiment as follow:
6. Dipping in solution of Chitosan at 0.5 % for 3 min
7. Dipping in solution of Hydrogen peroxide (H2O2) at 0.12 % for 3 min.
8. Dipping in solution of Ozonated water at 15ppm for 3 min.
9. Dipping in solution of Carboxymethyl cellulose at 1% for 3 min.
10. Dipping in tap water fruits for 3 min. (control).
The obtained results could be summarized as follows:
1. Hydrogen peroxide and chitosan treatments significantly reduced fresh weight loss of sweet pepper fruits as compared with untreated control.
2. Sweet pepper fruits treated with Hydrogen peroxide were the most effective treatments for maintained general appearance during storage and shelf life.
3. Sweet pepper fruits treated with Hydrogen peroxide gave good appearance at the end of shelf life (28 days at 10ºC + 2 days at 20 ºC).
4. Sweet pepper fruits treated with Hydrogen peroxide or chitosan were the most effective treatments on minimizing decay incidence during all storage period and shelf life condition.
5. Sweet pepper fruits treated with Hydrogen peroxide or chitosan were the most effective treatment in reducing the loss of firmness during storage and shelf life condition.
6. Control treatment was less effective in reducing firmness loss during storage and shelf life condition compared with the other treatments.
7. Sweet pepper fruits dipped in Hydrogen peroxide were significantly higher in fruit total soluble solids, ascorbic acid and total carotenoid than other treatments during storage and shelf life
8. . A sweet pepper fruit dipped in Hydrogen peroxide had the lowest value of total carotenoid content as compared with other treatments or untreated (control) during storage and shelf life.
9. Sweet pepper fruits treated with Hydrogen peroxide followed by chitosan treatment were the promising technique for maintaining quality and extending the shelf life of sweet pepper fruits.
Conclusions
from the previously mentioned results, it can be concluded that:
1. Productivity of sweet pepper (Lareka F1 hybrid) and fruit quality were improved by using magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK as a preharvest treatment.
2. Using magnetic irrigation water +75% NPK or magnetic irrigation water +50% NPK as a preharvest treatment improved storability of the fruits.
3. Dipping fruits in Hydrogen peroxide at .012% or chitosan at 0.5 % improved storability of fruits, keeping quality after harvest and gave fruits with good appearance till 28 days of at 10˚C + 2 days at 20˚C without decay.