الفهرس 
Introductionيوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Pelargonium graveolens (Rose-scented pelargonium) is a rich VOs aromatic herb with a rose scent. It is cultivated all over the world and consider one of the most important aromatic plants in Egypt. Pelargonium graveolens has been used in aromatherapy, traditional, perfumery industry, and cosmetics products.
Plant biostimulants are any substance or microorganism that are applied to plants, seeds, or roots to stimulate plants natural processes including increase nutrient utilization efficiency and abiotic stress tolerance. Brassinosteroids are a naturally occurring group of plant steroid hormones that are vital for plant growth and development. They have a broad biological activity, control several important agronomic traits such as plant geometry, flowering time, stress tolerance, and seed production. Seaweed extract containing complex polysaccharides, fatty acids, vitamins, plant hormones, and mineral nutrients are widely used in many crops to promote growth and tolerance to different abiotic stresses. Chitosan is another naturally occurring, compound with many potential benefits for agriculture. It has been used to increase yields, improve agro-ecological sustainability, and enhance plant defense systems against biological and environmental stress conditions. Additionally, CH can benefit plant nutrient uptake, remediate contaminated soils by removing heavy metals, and improving soil structure.
The present investigation was carried out during the two successive seasons 2020/2021 and 2021/2022 at the floriculture nursery and laboratory Faculty of Agriculture, Minia University and Medicinal and Aromatic Plant Department, Horticultural Res. Institute, Agricultural Research Centre, Giza, Egypt. The aim of this study is to improve the growth and VOs production P. graveolens plant using some biostimulants (BRs, SWE, and CH).
Unlike CH or SWE results showed that VOs % of all cuts were significantly varied following the application of BRs with no significant interaction between these two factors. Also, overall results showed that VOs % was increased in the 2nd cut (0.260-0.340 %) than the 1st one (0.230- 0.310 %) but it decreased again in the 3rd one (0.217-0.290 %) which had generally the slightly higher values for all treatments than the 1st one. Overall, plants which treated only with 2 g/l SWE had the lowest volatile oils (0.260 %) however the highest percentage (0.340 %) was for plants treated with 0.3 g/ BRs +1g/l CH).
All investigated applied plant biostimulants significantly improved VOs yield because of increasing the plant fresh weight as well as VOs %. However, there were no significant interactions between the investigated factors. In the 1st season the VOs yield was significantly and gradually augmented by about 50 % over the control plants achieving 6.186 ml/plants for the highest BRs concentration. Overall, the lowest VOs yield (2.578 ml/plant) being for untreated plants however the highest ones (7.352 and 7.346 ml/plant) was estimated for plants treated with 0.3 g/l BRS + 1g/l CH1 or WSE respectively.
Chlorophyll a, b and carotenoids showed significant interactions between the BRs and CH or SWE in both seasons. The lowest and highest chlorophyll a content in the 1st season 2.424 and 2.897 mg/g fresh weights were for untreated plants and (0.3 g/l BRs + 1 g/l CH). Almost CH 2 g/l and SWE 2g/l treated plants had a superior effect than other concentrations. The lowest chlorophyll b (1.232 mg/g fresh weight) being for plants treated with BRs 0.1 g/l + 2 g/l SWE nevertheless the highest content (1.768 mg/g fresh weight) was assessed for plants treated with (0.2 g/l BRs + 1 g/l CH). Rose-scented geranium plants had the lowest carotenoids (1.018 mg/g fresh weights) when treated only with 0.3 g/l BRs.
The ANOVA revealed that BRs as well as CH or SWE significantly affected the N % of rose-scented geranium. Overall, the lowest N % (1.070 %) being for non-treated plants however, the highest value (1.503 %) was for plants treated with BRs 0.3 g/l + 1 g/l CH or 2 g/l SWE. Almost the gradual increase of BRs caused an increase of N % regardless the CH or SWE treatment. Dissimilar to N % the P % was significantly differ only due to BRs application with no significant difference among the two investigated factors. The lowest and highest P were for non-treated plants, and these treated with 0.1 or 0.2 g/l BRs + 1 g/l CH or 2 g/l CH.
Potassium % significantly responded to both investigated factors but, there was no significant difference in K % (0.683 and 0.718 %) among CH or SWE concentrations.
Plants which did not treat with any of these biostimulants had the lowest K % concentration (0.573 %). Plants treated with 0.2 g/l BRs + 1 g/l CH had the highest K % but this value did not significantly differ compared with many other treatments. Therefore, the investigation suggested that treated rose-scented pelargonium which grown in clayey soil under the conditions on Minia Governate with BRs 0.3 g/l + SWE 1 g/l or BRs 0.3 g/l + CH 2 g/l for times could improve the VOs production by increasing the plant fresh weights during the 3 cuts as well as increasing VOs %. The VOs yield for these plants were (7.352 and 7.347 ml/plant) which increased by about 3 times than untreated plants (2.578 ml/plant).
Overall, the lowest VOs yield (2.578 ml/plant) being for untreated plants however the highest ones was estimated for plants treated with 0.3 g/l BRS + 1g/l CH1 or SWE respectively. Similar observations were estimated in the 2nd season.