There have been significant impacts of the current COVID-19 pandemic on society including high health and economic costs. However, little is known about the potential ecological risks of this virus despite its presence in freshwater systems. In this study, we aimed to evaluate the exposure of Poecilia reticulata juveniles to two peptides derived from Spike protein of SARS-CoV-2, which was synthesized in the laboratory (named PSPD-2002 and PSPD-2003). For this, the animals were exposed for 35 days to the peptides at a concentration of 40 µg/L and different toxicity biomarkers were assessed. Our data indicated that the peptides were able to induce anxiety-like behavior in the open field test and increased acetylcholinesterase (AChE) activity. The biometric evaluation also revealed that the animals exposed to the peptides displayed alterations in the pattern of growth/development. Furthermore, the increased activity of superoxide dismutase (SOD) and catalase (CAT) enzymes were accompanied by increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and hydrogen peroxide (H₂O₂), which suggests a redox imbalance induced by SARS-CoV-2 spike protein peptides. Moreover, molecular docking analysis suggested a strong interaction of the peptides with the enzymes AChE, SOD and CAT, allowing us to infer that the observed effects are related to the direct action of the peptides on the functionality of these enzymes. Consequently, our study provided evidence that the presence of SARS-CoV-2 viral particles in the freshwater ecosystems offer a health risk to fish and other aquatic organisms.

Intercropping system has been reported to enhance quality and yield obtained per unit area.Therefore,the current study was carried out to assess the impact of intercropping of Zucchini or broad beans with strawberry and also, intercropping (IC) Zucchini with broad beans on growth, quality, yield and the economic viability of the studied crops in the mixed IC, compared to the mono-cropping of these crops. A field experiment was carried out during 2017- 2018 and 2018-2019 . According to results of this study, intercropping of strawberry with broad beans achieved significantly the highest levels of anthocyanin content in strawberry fruits compared to the other treatments in both seasons. Maximum yield of strawberry crop was obtained from sole cropping as well as that obtained from strawberry-broad beans intercropping. Intercropping of Zucchini with broad beans resulted in significantly higher yields of both crops as compared with their sole cropping. Yield of broad bean and Zucchini increased by 18.1% and 26.9 % respectively as compared with their sole cropping which indicate yielding efficiency enhancement as a result of intercropping. Land equivalent ratio (LER) of strawberry- Zucchini intercropping was, on average1.2 for both years. Whereas, with regard to strawberry-broad beans intercropping was, on average for1.3 for both years, while it was 2.45 when Intercropping Zucchini with broad bean. Intercropping Zucchini with broad bean gave the highest relative yield for both of them compared with the other treatments and also, the highest monetary advantage index (MAI)

In the present investigation, effect of calcium chloride (CaCl2) used as foliar application (0, 10, 20 mM) was studied on morphological, yield, and quality of lettuce (Romaine and Green Waves cultivars) during 2017/2018 and 2018/2019 seasons. Our results indicated that, foliar spray of calcium chloride either at 10 or 20 mM significantly increased vegetative growth and yield parameters i.e., leaf number per plant, fresh and dry leaf weight compared to control treatment. Also, foliar spray of calcium chloride resulted in a significant increase in yield and quality parameters i.e., TSS, chlorophyll content and Vitamin C. ‘Romaine’ cultivar was significantly superior to ‘Green Waves’ cvs in plant height, fresh and dry weight of the leaves, TSS and chlorophyll content. However, there was no significant difference in vitamin C content between the two tested cultivars. ‘Green waves’ cv. sprayed with 20 mM CaCl2 gave the highest significant leaf number per plant. Fresh and dry leaf weight of ‘Romaine’cv recorded the highest values when the plants were sprayed with 20 mM CaCl2 in both seasons., In the first season, ‘Romaine’cv sprayed with 20 mM of CaCl2 produced the highest total yield, while the highest total yield in the second season was obtained from plants of both tested cvs sprayed with 20 mM CaCl2. ‘Romaine’ cultivar treated with 20 mM of calcium chloride as foliar application had the highest TSS and chlorophyll content. Fascinatingly, high association existed between total yield and all studied traits, except leaf number per plant. Overall results suggest applying calcium chloride as foliar application at 20 mM for improving yield quantity and quality in both ‘Romaine’ and ‘Green Waves’ cultivars.

The current study was performed at the Research Farm of Faculty of Agriculture, New Valley University during 2017/2018 and 2018/2019 seasons in order to evaluate response of onion cv. Giza 6 to some organic fertilizers, i.e., cattle manure and poultry manure in addition to mineral fertilizers as control treatment. The results obtained showed that the vegetative growth characters and yield components of onion plants were significantly influenced by fertilizers kinds. Combination of poultry manure at 75% of recommended fertilizers and 25% of mineral fertilizers recorded the highest values for both vegetative growth characters and yield components, i.e., plant height, leaves number, plant fresh and dry weight, crop growth rate, bulb fresh weight, bulb diameter, bulb dry matter, marketable yield and total yield in a comparison to mineral fertilizers (control) in both seasons. While, the content of chlorophyll a, b, total carotenoids, N, P and K in onion leaves and vitamin C, sulfur volatile oil and TSS in onion bulb were increased significantly by application of poultry manure at 25% of recommended fertilizers plus 75% of mineral fertilizers compared to mineral fertilizers (control) in both seasons. It can be concluded that application of poultry manure at 75% of recommended fertilizers plus 25% of mineral fertilizers increased growth , yield and improved bulb quality of onion plants cv. Giza 6 under the New Valley Governorate conditions