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To support the search for alternate chemical-free strategies to enhance plant growth and control plant diseases, we present an overview of the potential use of Biochar (BC) a product synthesized through pyrolysis from organic and agricultural waste used as a soil amendment, in suppressing broad range plant pathogens. A broad-spectrum BC effect contributes to the control of soil and foliar pathogens by altering the root exudates mechanism of the host plant, soil health and nutrient mobilization that affect the colonization of antagonistic microorganisms. Induction of plant defense mechanism by adding BC in potting medium to reduce foliar pathogens by the activation of defensive responses and induction of reactive oxygen species signaling in the plant system. Although few reports have been found for controlling oomycetes, viruses and bacterial pathogens through the application of BC, reports indicated that adding BC has potentially changed the soil microbiota colonization which contributes to disease suppression. BC also controls nematodes and harmful insects of plants. In addition, the main mechanisms of action for plant parasitic nematodes are changes in soil structure and could increase the biocontrol microorganism in the rhizosphere which resists nematodes colonizing and penetrating the plant system. Using BC-based amendments is a promising strategy with a carbon sequestration strategy, created on zero waste, as part of the integrated management of pathogens and parasites. Comprehensively, it is needed to be standardized the dosage and feedstock of BC in terms of sustainable production and disease control.

Drought stress is one of the primary stresses that reduce crops’ yield in some parts of the world. In this regard, to mitigate drought stress effects on plants, farmers usually apply chemical fertilizers that lead to environmental issues. This study aimed to investigate the effect of biofertilizer application containing potassium-solubilizing bacteria (Pseudomonas koreensis and Pseudomonas vancouverensis), phosphorus-solubilizing bacteria (Pseudomonas putida), and nitrogen-fixing bacteria (Pantoea agglomerans) as an environmentally friendly biofertilizer for the growth and uptake of some essential nutrients in maize and its effect on drought tolerance. To achieve this, a Completely Randomized Design with ten treatments experiment was conducted in greenhouse conditions. The findings revealed that biofertilizers have the potential to improve maize yield and physiological characteristics, particularly under drought stress. The discussion section explores the mechanisms through which biofertilizers exert their effect and discusses practical implications for agricultural practices and environmental sustainability. Overall, this study contributes valuable insights into sustainable agricultural practices and has the potential to inform decision-making processes for farmers and policymakers.

Environmental stresses, such as drought, represent the most limiting factors for agricultural productivity. Drought stress has drastic effects on the growth of canola plants. This study investigates the effects of inoculation with Pseudomonas fluorescens FY32 on the growth and antioxidant status of canola cultivars under drought stress induced by polyethylene glycol (PEG). The results show that bacterial inoculation improves the aerial dry weights and root length of canola plants under moderate drought stress. Peroxidase activity, as an antioxidant enzyme, increased in response to drought stress, whereas catalase activity remained constant, and polyphenol oxidase activity decreased. Compared to non-inoculated plants, inoculated plants showed significantly higher activities of antioxidant enzymes under drought stress. The inoculated canola cultivar Hyola308 exhibited a better protection mechanism against drought stress and was more tolerant than other cultivars exposed to drought stress, possibly due to its increased growth parameters and antioxidant enzyme activities. These results suggest that inoculation with the Pseudomonas fluorescens FY32 strain might alleviate the adverse effects of drought stress and lead to less stress pressure on plants.

Climate change-induced flooding has a profound impact on plant growth and development, posing a significant abiotic stressor that significantly affects the yield and quality of cabbage and cauliflower. In many regions, cabbage and cauliflower is severely affected by flooding stress during the cultivation period. This study aimed to assess and compare the effects of flooding stress on the morpho-physiological and biochemical properties of cabbage and cauliflower at different harvest times. In this context, cabbage and cauliflower seedlings were exposed to excess water, and essential parameters, such as photosynthesis, antioxidant enzymes, chlorophyll fluorescence, and certain agronomic features. As a result of flooding stress, significant decreases occurred in agronomic features were measured. The results showed significant decreases in agronomic parameters, including aboveground and underground fresh and dry weights, as well as leaf area. It was observed that the damage rate of plants increased as the exposure time to flooding stress increased. In our experiment, proline, an essential amino acid, significantly increased under flooding stress at different harvest times. Furthermore, the activity of catalase and ascorbate peroxidases, which are reactive oxygen species (ROS), also significantly increased in our investigation. In our experiment, we observed significant increases in proline, an essential amino acid, under flooding stress at different harvest times. Additionally, the activity of catalase and ascorbate peroxidases, which are reactive oxygen derivatives (ROS), also significantly increased. Furthermore, decreases were noted in stomatal conductivity, photosynthetic efficiency, leaf temperature (°C), and chlorophyll fluorescence levels. The application of flooding stress at various harvest times had a negative impact on the growth and development of cabbage and cauliflower plants, leading to significant alterations in their physiological and biochemical properties.

Root rot is a damaging disease caused by various pathogenic fungi including, Fusarium spp., Rhizoctonia spp., and especially oomycetes. This disease poses significant challenges to food crop production worldwide. Pythium and Phytophthora, most species of these genera, are fungus-like pathogens that can grow and expand in diverse agroecosystems, inflicting severe damage to the root systems of numerous food crops, including cereals, vegetables, and legumes. Multiple factors contribute to the proliferation of root rot, including temperature, soil moisture levels, and the existence of vulnerable host plants. Based on a wide range of scientific literature, this paper examines the impact of the disease on plant safety, emphasizing the substantial yield losses and economic harm faced by farmers worldwide. The paper provides also a comprehensive overview of the global prevalence, impact, and management strategies associated with root rot infections. A special highlight is directed at symptoms, infection process, and pathogenicity mechanisms employed by Pythium and Phytophthora species, with a particular case of olive root rot caused by these two pathogens. Additionally, detection strategies of pathogenic oomycetes are discussed as well, from conventional to recent tools that are employed now in the plant pathology field. Finally, various preventive and management strategies are provided in this work. These include cultural practices, chemical control measures, and biological control agents, from bacteria to antagonistic fungi with a special focus on the use of Trichoderma spp. strains, and host resistance breeding. The limitations and challenges associated with these strategies, such as the emergence of resistant strains and environmental concerns, are also addressed. In conclusion, this review helps to understand the biology, pathogenicity, and management options for these pathogens, which is crucial for developing sustainable solutions to mitigate the impact of root rot, ensuring food security, and raising sustainable agriculture in the face of this significant challenge.

Drought is one of the main devastating environmental factors limiting crops’ development and productivity. This study investigated the role of combining intercropping and co-inoculation of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) to protect barley and alfalfa against drought damage. The experiment design consisted of four inoculation treatments: (1) non-inoculated plants (C), (2) plants inoculated with AMF consortium (AMF), (3) plants inoculated with the bacterial consortium (PGPR), and (4) plants co-inoculated with AMF + PGPR (AMF + PGPR), and two irrigation regimes: (i) well-watered, equivalent to 75% field capacity (FC), and (ii) drought, where watering was maintained at 35% FC. For each treatment (inoculated or not inoculated and stressed or not stressed), the plants of barley and alfalfa were monocropped and intercropped. Growth (shoots and roots dry weight), physiological (stomatal conductance and chlorophyll fluorescence), and biochemical (stress markers, osmolytes contents, and antioxidant enzyme activities) parameters were all measured. The results showed that applying intercropping and microbial inoculation AMF or/and PGPR enhanced the tolerance of plants to drought stress. The most pronounced effect was displayed by combining intercropping system and co-inoculation of AMF + PGPR, which improved shoot and root dry weight by 141 and 280% in barley and by 512 and 533% in alfalfa, respectively, compared to their respective uninoculated monocultures. Similarly, combining intercropping and co-inoculation with AMF + PGPR enhanced acid phosphatase, superoxide dismutase, and catalase activities by 125%, 161%, and 58% in barley and by 114%, 311%, and 112% in alfalfa, respectively, compared to their respective uninoculated monocultures. Furthermore, the thousand-seed weight was increased by 73% in barley intercropped and inoculated with AMF +PGPR. These findings revealed that intercropping barley and alfalfa and co-inoculation of AMF +PGPR may provide a sustainable approach to enhance drought tolerance, increase crop productivity, and promote food security.