Hossam Ahmed Ashour

The current study was carried out to examine the impact of humic acid or chitosan applications on morphology and physiology attributes of Paspalum vaginatum Swartz. cv. Salam grown under drought stress. Drought stress was enforced by various watering intervals (2, 5, 8 and 11). The plants subjected to various watering intervals were sprayed biweekly with either humic acid (HA) or chitosan (CHT) each at concentrations of 300 and 600 ppm, whereas the tap water was used as control. The findings indicated that drought stress decreased all growth traits (such as, sward height, lawn density and dry weights of clippings and underground parts), total chlorophylls, total carbohydrates, N, P and K%, while proline, phenols content and Enzyme activity (CAT, APX and SOD) were raised. The plants foliar sprayed with HA or CHT at higher doses led to boost in the tested growth traits, total chlorophylls, total carbohydrates, N, P and K%, proline, phenols and enzyme activity with superiority of HA. Based on the outcome of the present research it can be inferred that, foliar application of HA at 600 ppm can ameliorates the harmful impacts of drought stress on physiology and growth traits of Paspalum vaginatum.

A pots experiment was conducted to assess the stress effects of salinity and water deficit on Lagerstroemia indica L. Salinity stress was imposed by irrigating with saline water at concentrations of 500, 1000, 2000, or 3000 ppm, in addition to the control (tap water of 280 ppm). Whereas water deficit was applied by using tap water for irrigation at intervals of 4, 6, 8, or 10 days. The treatments were arranged in a split-plot design, with the salinity treatments assigned to the main plots and the water deficit treatments assigned to the subplots. The results indicated that vegetative growth and flowering parameters (plant height, number of leaves/plant, number of branches/plant, stem diameter, root length, dry weight of shoots, number of flowers/plant and flower diameter), as well as total chlorophylls, total carbohydrates, N, P, K+ and Ca2+ % were reduced in response to both salinity and water deficit stresses. In contrast, both stresses resulted in an increase in the concentrations of Na+, Cl−, proline, total phenolics and antioxidant enzymes activities (CAT, SOD and APX) in leaves. The interaction effects showed that in plants irrigated every 6 or 8 days with tap water or every 4 days using a salt concentration of 1000 or 2000 ppm, the reduction in growth and flowering parameters, total chlorophylls, total carbohydrates, N, P, K+, and Ca2+ % was insignificant. Compared to unstressed plants, the accumulation of harmful Na+ and Cl- ions was insignificant in plants that were irrigated every 6 or 8 days with tap water or every 4 days with salinity levels up to 2000 ppm. Based on the findings of this study, it can be concluded that L. indica can be irrigated every eight days with tap water or every four days with saline water with concentrations up to 2000 ppm without any significant reduction in most of its vegetative growth and flowering characteristics.

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.

A field experiment was carried out to investigate the effect of different nitrogen forms and some biotreatments (Trichoderma viride, vermicompost and arbuscular mycorrhiza fungi) alone or in combination on vegetative growth, seed yield and some chemical traits of downy safflower (Carthamus lanatus L.). Nitrogen was supplied as ammonium sulfate, ammonium nitrate and urea at the rates (5, 3 and 2 g/plant, respectively). Bio treatments included Trichoderma viride, vermicompost and arbuscular mycorrhiza fungi. The results showed that all nitrogen forms significantly increased the plant growth and yield, pigments content, and total carbohydrates in leaves and seeds, as well as N, P and K%, total phenols and oil content in seeds. All bio treatments significantly increased the tested parameters compared to control. The integration of ammonium sulfate with T. viride was the most effective treatment since determined the highest increases of the tested traits. Results showed that for enhancing downy safflower plant growth, and nutritional values of seed, the combined treatment of T. viride at 5 ml/plant and ammonium sulfate at 5 g/plant is recommended.

Salinity is one of abiotic stress that affects plant growth and production. The objective of this study was to investigate the effect of salinity and vermicompost on morphology and physiology parameters of Calliandra haematocephala. The experiment was carried out with salinity treatments at 1000, 2000 3000 ppm in addition to the control (tap water, 280 ppm), vermicompost treatments at 5%, 10%, 15%, and 20% in addition to the control. The results indicated that increasing level of salinity resulted in reduction in vegetative growth and flowering parameters (plant height, number of branches/plant, stem diameter, root length, fresh and dry weights of leaves and roots/plant, number of flowers /plant, as well as fresh and dry weights of flowers /plant), total chlorophylls, total carbohydrates, K⁺%, Ca²⁺%, and K⁺/Na⁺ ratio, while increased proline, Na⁺ and Cl⁻% in the plants. Catalase (CAT), superoxide dismutase (SOD), Ascorbate peroxidase (APX) enzyme activities significantly increased with elevating salinity level from 0 to 3000 ppm. Application of vermicompost with any concentration had a positive effect on vegetative growth and flowering parameters, total chlorophylls, total carbohydrates, nutrient uptake, K⁺/Na⁺ ratio, proline content, enzyme activities and reducing accumulation of Na⁺ and Cl⁻% toxic ions in leaves. Based on the results, application of vermicompost at 20% recommended for alleviating the harmful efects of salinity on Calliandra haematocephala plants irrigated with saline water at concentration up to 3000 ppm.

Pot experiment was conducted to evaluate the effect of chitosan or brassinolide applications on morphology and physiology parameters of Azadirachta indica grown under water deficient stress. The plants received different irrigation intervals, and were sprayed monthly with either chitosan or barrasenolide each at concentrations of 50, 100 and 200 ppm, while the control plants were sprayed only with tap water. The results showed that water stress reduced all growth parameters, chemical constituents of pigments content, total carbohydrates, N, P and K %, total indoles, while proline and total phenols content were increased. Instead, the plants sprayed with the higher concentrations of chitosan or brassinolide resulted in significant increase in growth parameters, pigments content, total carbohydrates, proline content, N, P and K %, total indoles while reduced total phenols content. Based on the obtained results it can be concluded that, foliar application of chitosan or brassinolide at 200 ppm can alleviate the adverse effects of water deficient stress on the growth and physiology parameters of Azadirachta indica.

Monarda citriodora L. plant is an important aromatic and medicinal plant (Fam. Lamiaceae). It is economical importance due to its rich in Thymol compound in the volatile oil. The dependency on the use of chemical fertilizer as a source of plant nutrients and their high cost is further associated with land soil degradation and environmental pollution. The objective of this study was to investigate the tested of three levels of chemical fertilizers (recommended dose 100% NPK, 300:200:100 kg/fed., 75% and 50% NPK). As well as foliar spray of moringa leaves extract (MLE) as growth promoting at 0.0, 1:40, 1:30 and 1:20 and their interactions between them on essential oil production, total phenolic content, total flavonoids content and antioxidant activity of Monarda citriodora L. plant. The highest level of NPK 100% (RD) improved the most chemical contents followed by 75% and then 50%. The different concentrations of MLE significantly increased the chemical contents as compared to the control treatment. These constituents increased gradually with increasing the concentration of MLE up to (1:20). Under the same level of NPK, MLE application increased the chemical constituents comparing to NPK without MLE spray. Also, it was observed that the use of the natural extract (MLE) combined with low levels of chemical fertilization lead to increase these constituents compared to high levels of the chemical fertilization (NPK) without spraying the MLE extract. So, applying the natural extract of MLE can be partial substitution of the chemical fertilizers and produced a high quality of Monarda citriodora L., plants.

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.

Pots experiment was conducted to investigate the effect of bio-stimulators chitosan (CHT) or humic acid (HA) on Vitex trifolia ‘Purpurea’ exposed to salinity stress. Salinity stress was imposed by irrigation with saline water at concentration of 1000, 2500 and 5000 ppm, in addition to control (280 ppm), plants exposed to salinity were sprayed every 4 weeks with either CHT at concentrations of 30, 60 and 90 ppm or HA at concentrations of 1000, 1500 and 2000 ppm, while control plants sprayed only with tap water. The results showed that, with increasing salinity stress all vegetative growth parameters were decreased and chemical constituents including total chlorophylls total carbohydrates, K+ %, Ca2+ % and K+/Na+ ratio were reduced. In contrast, elevating salinity stress increased contents of proline, total phenolic, Na+ %, Cl− %. On the other hand, foliar application of either CHT or HA had favorable impact on increasing vegetative traits and chemical compositions, meanwhile reducing accumulation of total phenolic, Na+ and Cl− % toxic ions in leaves, HA was generally more effective than CHT. Based on the results, it can be recommended that, CHT or HA at high concentration was the best effective treatments; however, HA was superior and economic treatment recommended for alleviating the adverse impact of salinity stress on Vitex trifolia ‘Purpurea’ plants irrigated with saline water at concentration up to 5000 ppm.

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.