الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
 |  | from | 213 |  |  |
| | | from | 213 | | |
Abstract
Tamer Ibrahim Mahmoud Ibrahim Dawood: Effect of Silicon and Amino Acids on Growth and Yield of Oregano Plant (Origanum syriacum L.). Under Salt Stress Conditions in North Sinai Region. Unpublished Ph.D. Thesis, Department of Horticulture, Faculty of Agriculture, Ain Shams University, 2017.
A field experiment was carried out during 2013 and 2014 seasons, at North Sinai Region, El-Maghara Research Station, Desert Research Center, Egypt, to determine the effect of foliage spray of silicon ”Si” (0, 1000 and 2000 ppm) and amino acids (0, 200 and 400 ppm) under irrigation by saline water (at ECw 4.11, 6.31 and 9.44 dS/m) on vegetative growth, herb yield, volatile oil production and chemical composition of oregano plant (Origanum syriacum L.). The first level of water salinity (4.11 dS/m) was obtained from a natural well and the second and third levels (6.31 and 9.44 dS/m) were made up by adding NaCl to the first level.
The results showed that increase in saline water levels decreased the vegetative growth parameters (plant height, number of branches, herb fresh and dry weights per plant and per feddan in addition to root fresh and dry weight per plant), essential oil %, essential oil yield per plant and per feddan, chlorophyll a & b, carotenoids content, total carbohydrates, N, P, K and Si elements. Opposedly, increase of saline water levels increased Na and Cl elements together with proline content.
Supplementary Si as foliar spray treatments ameliorated to a reasonable degree the negative effects of salinity on oregano plant growth. Application of Si increased not only vegetative growth parameters but also increased chlorophyll a and b, total carbohydrates, elements of N, P, K and Si in addition to proline contents, while at the same time it decreased Na and Cl contents. The highest values in vegetative growth parameters understudy were obtained when 2000 ppm Si was applied.
Similarly, supplementary amino acids as foliar spray treatments compensated for the negative effects of salinity on oregano plant growth. Application of amino acids had an equivalent and similar impact on both vegetative growth parameters and internal chemical constituents studied as supplementary Si did. The highest values in vegetative growth parameters were obtained when 400 ppm amino acids was applied.
The combined effect between saline water 4.11 dS/m level, Si at 2000 ppm rate and amino acids at 400 ppm rate led to the highest values in all the vegetative growth parameters studied, essential oil yield per plant and per feddan, chlorophyll a and b, total carbohydrates, N, P, K and Si contents inside oregano plants in both seasons. Whereas under saline water 9.44 dS/m level without any Si supplementation plants gave the lowest values of the above parameters.
Results suggest that the negative effects of salinity on the growth and internal chemical constituents of oregano plants can be ameliorated to some extent by foliar application of both silicon and amino acids treatments.
Keywords:
Oregano, Origanum syriacum, Saline water, Salt stress, Silicon, Si, Amino Acids, Vegetative growth, Essential oil, Internal chemical composition.