الفهرس 
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Abstract
This study was laid out during the two seasons 2022 and 2023 at the Nursery of Ornamental plants, Fac. Agric., Minia Univ. to evaluate the effect of humic acid in form of potassium humate (0, 1000, 2000 and 4000 ppm) on alleviating the bad effects of irrigation water salinity (control, 800, 1600 and 2400 ppm NaCl) in addition to their interactions on growth characters, oil productivity and some chemical constituents of Rosmarinus officinalis plant.
The obtained results could be summarized as follow:
I-Effect of irrigation water salinity on:
I-A- Vegetative growth characters:
All vegetative growth parameters of Rosmarinus officinalis (plant height, stem diameter, branches and leaves number, leaf area, herb fresh and dried weights) were significantly increased under low salinity level (800 ppm NaCl), but they significantly decreased with rising salinity level (1600 and 2400 ppm NaCl) comparing with the control in both cuts during both seasons.
I-B- Essential oil productivity:
The effect of salinity on oil production (% and yield ml/plant) was significantly varied. where the essential oil percentage was positively increased under 800 and 1600 ppm NaCl, and negatively decreased under the upper concentration (2400 ppm NaCl) comparing with the control in both cuts during both seasons. Moreover, the essential oil yield was positively increased under 800 ppm NaCl, and negatively decreased under the upper concentrations (2400 ppm NaCl) comparing with the control in both cuts during both seasons.
I-C- Chemical constituent parameters:
1. Photosynthetic pigments
This study was taken place at the Nursery of Ornamental plants, Fac. Agric., Minia Univ. during the two seasons of 2022 and 2023 to study the impact of irrigation water salinity at 0.0, 800, 1600 and 2400 ppm NaCl, humic acid (0.0, 1000, 2000 and 4000 ppm) and the interactions between them on vegetative growth characters, volatile oil production, photosynthetic pigments and some mineral contets of Rosmarinus officinalis plant grown in sandy soil.
Data showed that all examined traits of vegetative growth (plant height, stem diameter, number of branches/plant, number of leaves/plant, leaf area, herb fresh and dry weights) and essential oil productivity (% and yield ml/plant) as well as some chemical constituents (chlorophyll a, b and carotenoids and NPK%) were decreased by increasing salinity level comparing with control during both seasons. At the same time, salinity concentrations increased both of Na% and proline content (µg/g) in dry leaves during both seasons.
Humic acid treatments led to significant increase in all abovementioned traits of vegetative growth and essential oil productivity as well as some chemical constituents except Na% and proline content (µg/g) in dry leaves during both seasons, were decreased. 4000 ppm humic acid was superior.
In conclusion, spraying plants with 4000 ppm humic acid alleviate the bad impacts of moderate salinity levels.
Keywords: Rosemary – salinity – water quality – humic acid.
2. Nitrogen, phosphorus and potassium percentages:
The NPK% in dry leaves in the second cut during the both seasons were significantly decreased due to irrigated with saline water comparing with the control.
3. Sodium percentage and proline content:
Irrigated plants with saline water at the three used concentrations led to significant increase in sodium (%) and proline content (µg/g) in dry leaves in the second cut during the both seasons comparing with the control.
II- Effect of humic acid on form of potassium humate:
II-A- Vegetative growth characters:
Spraying plants with humic acid at the three levels (1000, 2000 and 4000 ppm) let to a significant increase in all vegetative traits (plant height, stem diameter, branches and leaves number, leaf area, herb fresh and dried weights) facing the control in both cuts during both seasons. In all cases, the treatment of 4000 ppm was more effective than other treatments in this concern.
II-B- Essential oil productivity:
The effect of humic acid on oil production (% and yield ml/plant) was significantly positive. The treatment of humic acid at 4000 ppm was superior than other used treatments in both cuts during both seasons.
II-C- Chemical constituent parameters:
1. Photosynthetic pigments
Spraying plants with humic acid at the three used concentration (1000, 2000 and 4000 ppm) significantly increased chlorophyll a, b and carotenoids content in fresh leaves comparing with control in both cuts during both seasons.
2. Nitrogen, phosphorus and potassium percentages:
Spraying plants with humic acid at 1000, 2000 and 4000 ppm significantly increased NPK% in dry leaves in the second cut during the both seasons comparing with the control.
3. Sodium percentage and proline content:
Spraying plants with humic acid at 1000, 2000 and 4000 ppm led to significant decrease in sodium (%) and proline content (µg/g) in dry leaves in the second cut during the both seasons comparing with the control.
III- Effect of the interaction treatments on:
III-A- Vegetative growth characters:
The combination effect between salinized water and humic acid was significant for plant height, stem diameter, branches and leaves number, leaf area, herb fresh and dried weights facing the control in both cuts during both seasons. The best interaction treatment overall was produced from plants irrigated with 800 ppm and sprayed them with humic acid at 4000 ppm in all cases and 2000 ppm in some cases.
III-B- Essential oil productivity:
The combination effect between salinized water and humic acid was significant for oil production (%) and (yield/plant) facing the control in both cuts during both seasons. The best cobination was irrigated plants with 800 ppm and sprayed them with humic acid at 4000 ppm in all cases.
III-C- Chemical constituent parameters:
1. Photosynthetic pigments
The combination effect between salinized water and humic acid was significant for chlorophyll a, b and carotenoids content in fresh leaves relatively to control in both cuts throughout both seasons. The best combination was irrigated plants with 800 ppm and sprayed them with humic acid at 4000 ppm in all cases.
2. Nitrogen, phosphorus and potassium percentages:
The combination effect between salinized water and humic acid was significant for NPK% in dry leaves in the second cut during both seasons. The best interaction treatments were irrigated plants with 800 ppm and sprayed them with humic acid at 4000 ppm in all cases.
3. Sodium percentage and proline content:
The combination effect between salinized water and humic acid was significant for sodium (%) and proline content (µg/g) in dry leaves in the second cut during both seasons. The best interaction treatments were irrigated plants with 800 ppm and sprayed them with humic acid at 4000 ppm.