Asmaa Bader El-Din Sayed El-Attar

The present experiment was conducted to determine the effect chemical fertilization rates and foliar application of plant growth regulators PGRs (Kinetin or Napthaleneacetic Acid (NAA) and their interactions on growth, flowering, chemical composition of Ervatamia coronaria plants. The plants were fertilized monthly with NPK at the rate of 2, 4 and 6 g pot^-1, in addition to the control plants. Plants received the fertilization treatments were sprayed monthly with either Kinetin or NAA at 50, 100 ppm for each one, while the control plants sprayed with tap water. As general, the results indicated that within each level of fertilizer treatments, treating plants with different concentrations of PGRs (Kinetin or NAA) resulted in significant increase in tested vegetative growth (in terms of plant height, number of branches plant^-1, leaf area, number of leaves plant^-1, stem diameter, root length, fresh and dry weights of leaves, stems and roots), flowering parameters (Viz number of flowers/ plant, fresh and dry weights of flowers), chlorophylls content, total carbohydrates, N, P , K%, total indoles and total phenols, gibberellins, auxins and cytokinins compared to control, with superiority of NAA particularly the highest concentrations (100 ppm) . Under the same level of PGRs raising the fertilization rate caused a gradual and significant increase in all tested parameters compared to control. Based on the results, it can be recommended that for the highest quality growth and flowering parameters of Ervatamia coronaria, the plants could be sprayed with NAA at 100 ppm combined with 6 g pot^-1 NPK.

Plant production, soil quality, and a sustainable environment depend on climate change. Drought is a multidimensional stressor that seriously affects plant production. The most sensitive plant to climate change is the invasive goldenrod (Solidago canadensis L.), which has potentially high-value materials that can be used to develop a novel approach to controlling its spread. This study aimed to evaluate the impact of different applications (NPK-chemical fertilizers (T1) as control, nano-silicon (T2), nano-NPK (T3), nano-zeolite-loaded nitrogen (T4), and mixed nano-silicon with nano-zeolite-loaded nitrogen (T5)) on plant growth, flowering, chemical composition, yield, essential oil (EO) productivity, and tolerance of water deficit under newreclaimed soil. The results show that T5 application enhanced morphological traits and photosynthetic parameters (photosynthetic rate, CO₂ concentration, and water use efficiency while reducing transpiration rate) in goldenrod plants. Moreover, it promoted the plant nutrients uptake compared to the control. The highest total carbohydrate, flavonoid, and phenol contents, as well as a significant amount of the phytohormone indole-3-acetic acid (IAA), were obtained from the T5 application. Conversely, abscisic acid (ABA) and antioxidant enzymes of catalase (CAT) and superoxide dismutase (SOD) appeared with the highest amounts in control plants (T1).Th interaction effect of T5 and drought stress is indicated by increased EO productivity and therapeutic properties.Previous results provide a way to elevate drought stress resistance for the safety production of S. canadensis and improve their qualitative and quantitative trials as economical solutions to achieve an environmental approach to control their spread.

Global climatic change leads to many detrimental effects on all life forms. Outstanding case, salinity, and drought are considered multidimensional stress that severely affect plant growth and sustainable agriculture. Thymus vulgaris is a medicinal plant that has phytochemical constituents, and it is threatened by several abiotic stresses caused by climate change. Therefore, the present study aims to evaluate the physiological response and thyme tolerance grown on a newlyreclaimed saline sandy soil under drought conditions and treated by biochar-loaded biofertilizers, nano-zeolite, and nano-silicon through two consecutive seasons. The nanoparticles enhanced plant growth and alleviated the adverse effect of drought. Additionally, a synergistic effect was noticed when combining nanoparticles and biofertilizers. The quadruple combined treatment of nano-zeolite, nano-silicon, biochar, and organic matter (T7) significantly increased thyme morphological traits, photosynthetic parameters, oil, and yield compared to control treatment. Additionally, T7 increased the concentration of endogenous nutrients (N, P, K, Na, Ca, Mg, Zn, Fe, Mn), proline, total phenols, and total flavonoids, in addition to indoleacetic acid, gibberellic acid, and antioxidant enzymes in thyme compared to other treatments. T7 showed the lowest concentration of soluble sugars, abscisic acid, and transpiration rate. Interestingly, T7 increased the medicinal benefits of thyme by increasing its vital hydrocarbons, and oxygenated compounds. These findings introduce a dual benefit of nano-fertilizers in combination with biochar and organic matter in ameliorating soil salinity and drought along with increasing thymegrowth, productivity, and therapeutic value.

Standard Carnation flowers (Dianthus caryophyllus cv. Dover) were harvested at the paint brush stage in the early morning, pre-cooled at 4° C for 6-h then moved under dry conditions to the laboratory. Flowers were weighted and treated for 24-h with silver nanoparticles (AgNPs) at 0, 5 or 10 ppm in plastic buckets. After pulsing treatments, cut flowers were transferred to 500 mL glass jars containing 300 mL of preservation solution treatments including, individually, humic acid at 200, 400 or 600 ppm and Aloe vera gel at 2.5%, 5.0% or 7.5% (w/v) till the end of the experiment (when flower color began to fade, petals began to roll). Distilled water was used for the control and to prepare the tested solutions. 2% sucrose was added to all treatments including the control. Addition of all preservatives to vase solutions significantly increased all the studied characteristics of cut flowers compared to control (distilled water, least values). Nanosilver treatments have the potential to be used as preservative solutions for improving postharvest vase life and quality of carnation flowers. An increment in vase life, relative fresh weight, vase solution uptake, flower diameter as well as total chlorophylls in leaves, total carbohydrates and total phenols in leaves and petals was observed, in addition to a decrease in bacterial counts in vase solution. Best results were obtained using 5 ppm AgNPs + 5.0% Aloe vera gel followed by 5 ppm AgNPs +7.5% Aloe vera gel solutions. Aloe vera gel, especially 5.0% level, showed better results than humic acid when used alone or combined with AgNPs. Nanosilver at 5 ppm recorded better results than 10 ppm when used as a single treatment.

Field experiment was conducted to evaluate the influence of arbuscular mycorrhiza fungi (AMF) and foliar spray of plant growth regulators (PGRs) and their interaction on vegetative growth, seed yield and yield attributes and some biochemical criteria of chia (Salvia hispanica L.), in a split plot design with three replications. Plants grown in absence or presence of AMF were sprayed every 2 weeks with benzyl adenine (BA), CPPU [N-(2-chloro-4-pyridinyl)-N’-phenylurea], common name forchlorfenuron, and Naphthalene acetic acid (NAA) at 50, 20 and 50 ppm respectively, while control plants were sprayed with tap water. The results revealed that, inoculation with AMF generally caused significant augmentation in all studied growth, yield and yield attributes, total chlorophylls and carbohydrates content in leaves, augmentation in nutritional values of seeds like carbohydrates %, macronutrient, micronutrients, proteins %, total flavonoids, oil % compared to non-inoculated plants. In absence or presence of AMF, application of PGRs generally caused significant increases in the studied parameters compared to control. The interaction between NAA and AMF was more effective since gave higher increases in the studied parameters. It can be concluded that, cultivation of chia plant in presence of mycorrhiza with foliar application of NAA at 50 ppm is recommended for enhancing growth, and nutritional values of seed yield.

A pot experiments was carried out to evaluate the influence of growing media and combined treatments of NPK with either benzyladenine or gibberellic acid on growth, chemical constituents and anatomical structure of Dracaena marginata ‘Bicolor’. The plants were grown in two growing media; peat-moss, peat-moss+ sand (1:1, v v-1), received monthly NPK fertilizers (2 and 4 g pot-1) combined with either of benzyl adenine (BA) at 100 and 150 ppm or gibberellic acid (GA3) at 150 and 250 ppm, while the control plants received no treatments. As general, the results indicated that, peat- moss was superior to peat-moss+ sand medium on increasing most of vegetative growth parameters in terms of plant height, number of leaves/plant, leaf area, root length, as well as fresh and dry weights of leaves, stems and roots/plant, besides some macro elements represented in N, P, K, Ca and Mg% in both leaves and stems. While plants grown in peat-moss+ sand possessed significantly higher contents of total chlorophylls, total carbohydrates, Cu, Fe, Mn, Zn and B than those grown in peat- moss alone. Plants received combined NPK with either BA or GA3 resulted in significant increases in most of morphological and chemicals content over the control plants and it was outstanding that, GA3 was more effective than BA when they were combined with NPK. It can be concluded that for the highest quality, quantity growth and economic production of Dracaena marginata ‘Bicolor’, the plants could be grown in a medium of peat-moss and supplied monthly with NPK fertilizer at 2 g plant-1 along with foliar sprayed with 250 ppm GA3.