Tomatoes are an important agricultural product because they contain high concentrations of bioactive substances, such as folate, ascorbate, polyphenols, and carotenoids, as well as many other essential elements. As a result, tomatoes are thought to be extremely beneficial to human health. Chemical fertilizers and insecticides are routinely utilized to maximize tomato production. In this context, microbial inoculations, particularly those containing PGPR, may be utilized in place of chemical fertilizers and pesticides. In this study, we investigated the effects of PGPR (Bacillus subtilis, and Bacillus amyloliquefaciens) and cyanobacteria when utilized alone, and in conjunction with each other, on the growth, quality, and yield of fresh fruits of tomato plants. The results showed that the inoculation significantly increased all measured parameters of tomato plants compared with the control. Combined use of B. subtilis and B. amyloliquefaciens had a positive impact on tomato yield, increasing fruit yield. Moreover, leaflet anatomical characteristics were altered, with increased thickness of the upper epidermis, lower epidermis, palisade tissue, spongy tissue, and vascular bundles. Tomato fruit quality was improved, as measured by an increased number of fruit per plant (76% increase), fruit weight (g; 33% increase), fruit height (cm; 50% increase), fruit diameter (cm; 50%), total soluble solids (TSS; 26% increase), and ascorbic acid (mg/100 g F.W.; 75% increase), relative to the control, in the first season. In addition, fruit chemical contents (N, P, and K) were increased with inoculation. The results suggest that inoculation with B. subtilis and B. amyloliquefaciens could be successfully used to enhance tomato plant growth and yield.

T HE PRESENT study aimed to evaluate the effect of three levels of gibberellic acid solutions (50, 100 and 150 mg/L) on two sugar beet cultivars. (Farida and Sultan) under three field capacity (50 , 75 and 100%). This experiment was carried out at the Experimental Farm, Faculty of Agriculture, Suez Canal University, Ismailia, during the two growing successive seasons of 2013/14 and 2014/15. Results showed that all GA3 tested treatments statistically improved growth parameters, i.e., number of leaves, fresh and dry weights of leaves/plant, as well as, root yield, sucrose%, photosynthetic pigments (chlorophylls a, b and carotenoids), relative water content (RWC), leaf osmotic pressure (LOP) and the studied anatomical characters (thickness of mysophyll, thickness of midrib, thickness of palisade tissue, thickness of spongy tissue, average number of xylem vessels/vascular bundle, thickness of vascular bundle, thickness of collenchaymatous tissue and upper epidermis). Conclusively, this study indicates that, soaking seeds in GA3 solutions especially at 150 mg/L can decrease the effects of drought on growth and yield of sugar beet.

The harmful impacts of ozone (O3) on plant development and productivity have been excessively studied. Furthermore, the positive influences of its low concentrations still need to be explored further. The present study was performed to assess the impact of low concentrations of O3 on two sweet pepper hybrids under cold stress. The ozonated water was utilized for seed soaking or foliar application at concentrations of 0, 10, 20, 30, and 40 ppm. Seed soaking using ozonated water for 1 h was compared to soaking in distilled water as a control. Moreover, exogenously ozonated water was sprayed thrice at three-day intervals compared with untreated control. The differences between the applied methods (seed soaking and foliar application using ozonated water) were not statistically detected in most of the evaluated parameters. On the other hand, the evaluated hybrids displayed significant differences in the studied parameters, with the superiority of the Lirica evident in most germination and seedling growth parameters. Both applied methods significantly improved germination and seedling growth parameters. In particular, the concentration of 40 ppm displayed the highest enhancement of the germination index, coefficient velocity, and seedling quality. In addition, it promoted the seedling maintenance of high relative water content (RWC), chlorophyll, proline, and ascorbate peroxidase activity under cold stress conditions. Moreover, it protected the cell wall from damage by decreasing membrane permeability (MP). Generally, the best results were obtained from 40 ppm followed by 30 ppm of O3 as seed soaking or foliar spray. The results pointed out the possible use of O3 in a low concentration to protect the plants from cold stress during germination and early plant growth.

Chia (Salvia hispanica L.) is a specialty crop capable of providing healthy food and metabolites. The goal of our study was to explore the possibility of expanding seed yield, oil production, and metabolites of chia in response to amino acid, barthenosteriode, and algae extract treatments used as bio-stimulants. The experiment was conducted in the field in a randomized complete block design with three repeats. The treatments were (1) control (spray only with water), (2) amino acids with nutrients (2 mL/L vs. 4 mL/L), (3) brassinolide (5 mL/L vs. 10 mL/L), and algae extract (2 mL/L vs. 4 mL/L). The growth and yield measurements of chia, such as chlorophyll, carotenoids, amino acids, indoles, phenols, macro- and micronutrients, carbohydrates, total oil, and fatty acids were analyzed. The chia plants sprayed with growth stimulant materials showed increases in most studied characteristics, particularly algae extract at 4 mL/L, followed by algae extract at 2 mL/L during the first and second seasons. Meanwhile, amino acids at 4 mL/L led to the third-highest increases in most cases. Conversely, all bio-stimulant treatments decreased total phenols in leaves (mg/100 g f.w.), especially seaweed at 4 mL/L, compared to high levels in the control during both seasons. Control plants showed the lowest levels of the measurements mentioned previously when scored by barthenosteriode at 5 mL/L during the first and second seasons. GLC for fixed oil in chia showed the recognition of four biocomponents. i.e., oleic, linoleic, palmitic, and α-α linolenic acids. The main biocomponent was α-α linolenic acid and reach (49.7 to 57.9%). The application of seaweed at 4 mL/L could be exploited to improve growth, seed crop, fixed oil production, chemicals and bio-constituents, especially the fixed oil composition of chia (Salvia hispanica L.) plant.

Drought is one of the major environmental stresses that devastatingly impact squash development, growth, and productivity. Potassium silicate can attenuate the injuries caused by water stress. Hence, this study was designed to investigate the influence of three concentrations of potassium silicate; 10, 15, and 20 g/L on squash plants versus untreated control under three irrigation regimes; 100, 75, and 50% of estimated crop evapotranspiration (ET). The obtained results indicated that moderate (75% ET) or severe (50% ET) drought stress conditions gradually declined photosynthetic pigments, relative water content (RWC), mineral content, physiological parameters, and anatomical characteristics. These deleterious impacts were reflected on all growth and yield traits, i.e., plant height, fresh and dry weight of root and shoot, and fruit yield. On the other hand, the antioxidant enzyme activities; superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) significantly increased under severe drought stress at 50% ET followed by 75% ET. However, all evaluated exogenous applications of potassium silicate substantially enhanced photosynthetic pigments, RWC, N, P, and K content, antioxidant enzyme activities, and anatomical characters (periderm thickness, cortex thickness, midrib thickness, mesophyll thickness, number of xylem vessels per main vascular bundle, thickness of vascular bundle, thickness of collenchymatous tissue and upper epidermis, and thickness of collenchymatous tissue and lower epidermis). These desirable impacts were reflected in enhancing all growth and yield parameters. Conclusively, this study alludes that the exogenously applied of potassium silicate, particularly at 20 g/L, can alleviate the deleterious effects of drought stress and enhance the growth and productivity of squash plants, especially in arid environments.