Field experiments were carried out during the two successive summer seasons of 2015/2016 and 2016/2017. The experiments were accomplished in an open field located at Bader region, El-Beheira Governorate, Egypt to evaluate the effects of humic acid, indole butyric acid (IBA), and arbuscular mycorrhizal fungi (AMF) (Glomus mosseae) individually on vegetative growth, yield, and phytochemical characteristics of Hibiscus Sabdariffa (Roselle jamica). Experimental field plots were designed as randomized complete block design (RCBD). The obtained results of the two seasons, generally, showed that all treatments (HA, IBA, and AMF) individually enhanced the vegetative growth, yield of calyx, and phytochemical parameters of Roselle plants. The HA treatment was the most effective in enhancing most of the studied parameters and might be recommended for enhancing the vegetative growth, yield of calyx, and calyx phytochemical components of Roselle plants under the environmental conditions of Bader region, El-Beheira Governorate and other similar regions.

Two pot experiments were carried out under greenhouse conditions during the two successive winter seasons of 2017/2018 and 2018/2019 to enhance the performance of coriander (Coriandrum sativum L.) plants under salt stress conditions (NaCl at 0, 25, 50 and 75 mM). Along with the possibility of enhancing the plant growth, chemical composition, and secondary metabolites of essential oils. Foliar applications of selenium (25 and 50 ppm), nano selenium (25 and 50 ppm), glycine betaine (5 and 10 mM), and distilled water (control treatment) were applied on C. sativum plants. The foliage and root growth, chemical composition, and secondary metabolites of essential oils of coriander plants grown under salt stress were examined. The obtained results of the two seasons revealed that salt stress had significant deleterious effects on vegetative growth, fruit yield, essential oil yield, secondary components, and leaves chemical composition, while it enhanced the electrolyte leakage, proline content, Na + and Clof the leaves. Generally, the tested treatments: selenium, nano selenium, and glycine betaine varied in their significant effects on the studied characters. Selenium and glycine betaine treatments were more effective in improving coriander plants to salinity stress where they significantly increased almost all the studied parameters under saline compared to the control.

Two pot trials were carried out during the two successive Winter seasons of 2015/2016 and 2016/2017 at private commercial nursery, Damanhour city, El-Beheira Governorate, Egypt under greenhouse conditions. The objective of these experiments was to study the effect of foliar application with each of salicylic acid (SA) (50 and 100 mgL-1), triacontanol (TRIA) (25 and 50 mgL-1) and δ-aminolevulinic acid (ALA) (25 and 50 mgL-1) on Viola wittrockiana Gams L. (Blue with Blotch cultivar) grown under different concentrations of salinity (0, 20, 40 and 60 mM of NaCl). Generally, the tested materials were varied in their significant effects on studying characters. The obtained results of the two seasons indicated that increasing salinity levels from 20 to 60 mM significantly reduced all studied parameter levels, i.e., plant height, branches number per plant, shoot dry weight per plant, leaf area, root length and root dry weight, nitrogen, phosphorus, potassium, calcium, magnesium, and chlorophyll contents. While Na + and Clwere increased relative to control. Also, the results indicated that the salicylic acid, δ-aminolevulinic acid, and triacontanol significantly increased plant growth and chemical traits, as well as reduced the contents of Na + and Clcompared to the control (distilled water only) treatment. Application of triacontanol (25 mgL-1) or salicylic acid (50 mgL-1); improved vegetative, flowering, root growth and leaves chemical composition under salt stress during both seasons. Triacontanol enhanced salinity tolerance in both seasons by increasing proline accumulation. Under each salinity level, triacontanol (25 mgL-1) was the most effective treatment for mitigating the deleterious effect of salt stress in pansy plants.

The current investigation has been accomplished in a climate of the greenhouse at the farm of the Fac. of Agri, Damanhour Univ., El-Beheira Gov., Egypt, during two consecutive seasons of 2020/2021 and 2021/2022. The aim of this experiment was to evaluate the impact of two safe growth stimulants: seaweed extract of Oligo-x (SWE) and chitosan (CH) each at 0, 3 and 6 ml/l on vegetative growth, flowering growth, and the chemical composition of the leaves of Petunia axillaris plants cultivated in drought stress conditions. The acquired results for the two seasons showed that drought stress caused serious negative consequences on vegetative growth, flowering growth, and the chemical composition of leaves, while it increased the proline content and electrolyte leakage. Generally, seaweed extract and chitosan had a profound impact on the studied characteristics. For instance, the growth parameters including plant height, number of branches per plant, leaf area, shoot fresh and dry weights per plant, as well as root length and root fresh and dry weights per plant showed the highest values via the application of seaweed extract at 6 ml/l compared to the other treatments under study. In the same line, flowering parameters such as flowering duration, flower diameter, the number of flowers per plant, flower fresh and dry weights, and leaves chemical composition including total leaf carbohydrate exhibited the most significant improvements by the application of seaweed extract at 6 ml/l. On the contrary, the seaweed extract at 6 ml/l resulted in the lowest value of proline content, and electrolytic leakage. Regarding the chitosan treatment, the 6 ml/l concentration of the solution exhibited the highest values of the number of days to flowering, flower longevity and SPAD index in relative to the other treatments. All the studied traits were expressed using cross correlation analysis.