By-products of insect farming as a novel sustainable biofertilizer for crops

THE ROLE OF PLANT BIOSTIMULANTS AND GROWTH REGULATORS IN CLIMATE-RESILIENT AGRICULTURE: A REVIEW

The need for the most up-to-date, environmentally friendly techniques of controlling plant diseases and pests necessitates keeping an eye out for effective tools that provide a safe environment for human and animal fitness. In recent years, the usage of plant biostimulants (BS), which are derived from various organic materials through hydrolysis reactions, has increased. Soil microbes and plants immediately absorb these Biostimulants, which often consist of peptides, amino acids, polysaccharides, humic acids and phytohormones  with less energy requirement. This benefits not only growth but also the yield and quality of the harvested grain or fruit. These items are intended to promote and increase plant metabolism, reduce stress, etc., rather than to supply nutrients. These days, a variety of biotic and abiotic stresses hinder plant development, seed germination and seedling growth due to shifting climatic conditions, which reduces biological and economic yields. Plant growth regulators (PGRs) helps plant in mitigating different abiotic stresses and also enhances the adaptability of plants in stress conditions. A variety of PGRs, including ethylene (ET), salicylic acid (SA), abscisic acid (ABA) and jasmonates (JAs), are linked to improving plants' ability to respond to various stimuli. On the other hand, under both normal and stressful environmental conditions, PGRs like auxin, cytokinins (CKs), gibberellins (GAs) and relatively novel PGRs like strigolactones (SLs) and brassinosteroids (BRs) are engaged in plant growth and development. These PGRs are crucial for regulating stress adaptation through modulates physiological, biochemical  and molecular processes and activation of the defense system, upregulating of transcript levels, transcription factors, metabolism genes, and stress proteins at cellular levels.

Biofertilizers and Biostimulants for Sustainable Rosaceae Crop Production

The Rosaceae family includes some of the most economically important fruit and nut crops worldwide, such as apples, strawberries, and almonds. Increasing market demand and climate constraints have intensified reliance on synthetic fertilizers, leading to environmental degradation and reduced ecosystem resilience. In response, sustainable alternatives, such as organic fertilizers, biofertilizers, and biostimulants, have gained increasing attention. Here, we review recent findings in the application of these ecofriendly inputs in Rosaceae crops, using almonds (Prunus dulcis) as a representative case study. We highlight the roles of plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi in improving nutrient availability, stress tolerance, soil fertility, and crop productivity through mechanisms including biological nitrogen fixation, phosphate solubilization, siderophore production, phytohormone modulation, and enhanced plant defense responses. Evidence from field, greenhouse, and controlled experimental studies has indicated that rhizobacteria and mycorrhizal fungi, as well as organic fertilizers, enhance nutrient uptake, photosynthetic efficiency, fruit yields, and quality while supporting soil biodiversity and long-term orchard sustainability. Despite their demonstrated benefits, the adoption of biofertilizers and biostimulants in almond orchards remains limited. This review discusses the current challenges, knowledge gaps, and future perspectives for integrating microbial-based solutions into sustainable Rosaceae cultivation systems.

Growth and Phytoremediation Potential of Salicornia spp. Under Different Wastewater Irrigation Regimes: A Review

Salicornia is a genus of salt-tolerant plants capable of growing and producing biomass under conditions that severely constrain conventional agriculture. Beyond its ecological niche as a halophyte, Salicornia has emerged as a multifunctional crop for sustainable food, feed, and bio-based production in saline landscapes. The increasing generation of saline wastewaters and brines from aquaculture, municipal treatment, agro-industrial activities, and greenhouse systems intensifies the need for natural solutions that can recover resources while protecting soils and receiving ecosystems. This review synthesizes current understanding of how Salicornia species perform when irrigated with saline wastewaters, with particular attention to their dual role as productive crops and phytoremediation agents. It further examines the biological mechanisms underlying salt tolerance and the influence of wastewater characteristics on biomass production and phytoremediation performance. Overall, the evidence indicates that Salicornia performs particularly well in nutrient-rich, controlled saline effluents, whereas more complex wastewater matrices require careful contaminant management to ensure biomass quality and safe reuse. This synthesis positions Salicornia as a fundamental species for circular and climate-resilient strategies linking saline wastewater reuse with crop production, while emphasizing that standardized reporting, long-term field validation, and contaminant-aware biomass management remain essential to support wider adoption.

Effect of Biofertilization with Plant Growth-Promoting rhizobacillus (PGPR) on Growth and Productivity of maize (Zea mays L.) Compared to Chemical Fertilization

Background: Maize (Zea mays L.) is one of the world's most important cereal crops, and improving its productivity while reducing dependence on chemical fertilizers has become a major goal of sustainable agriculture. The potential role of plant growth promoting rhizobacteria (PGPR) as a biofertilizer evolved as appropriate substitute to neutralize adverse environmental impacts wielded by manmade agrochemical. Objective: This study aimed to evaluate the effects of Pseudomonas fluorescens and Bacillus subtilis, individually and in combination, on the growth and yield of maize compared with conventional NPK fertilization. Methods: A field experiment was conducted during the 2025 growing season at the Field Crops Research Station, College of Agriculture, University of Samarra, using a Randomized Complete Block Design (RCBD) with three replicates. Six treatments were evaluated: Untreated control (T1), Pseudomonas fluorescens (T2), Bacillus subtilis (T3), combined inoculation (P. fluorescens + B. subtilis) (T4), combined inoculation with NPK fertilizer (T5), and NPK fertilizer (20:20:20) only (T6). Vegetative growth and yield-related traits were recorded and statistically analyzed. Results: Inoculation of plants with PGPR bacteria resulted in a significant improvement in both vegetative growth and yield compared to the untreated control group. Pseudomonas fluorescens (T2) exhibited the highest vegetative growth rate, recording the highest plant height (148.00 cm), leaf area (365.00 cm²), leaf area index (2.63), and number of grains per spike (688 grains) compared control group recorded (92.33 cm), (10.67 plant⁻¹), (151.73 cm²), (0.70) respectively. Bacillus subtilis (T3), achieved the highest productivity, producing the largest number of spikes per plant (2.67 spikes) and the highest spike weight (283.50 g) compared control group recorded (2.00) and (161.60 g). Conclusion: The use of PGPR, and especially Pseudomonas fluorescens and Bacillus subtilis as potential biofertilisation agents is a promising sustainable alternative to chemical fertilisation that can enhance maize growth and production, while decreasing dependence on mineral fertilisers.

Application of Plant Growth-Promoting Rhizobacteria Consortia as Biofertilizers for Sustainable Cereal Production

Sustainable crop production is increasingly threatened by declining soil fertility, climate change, excessive agrochemical use, and rising food demand.  Cereal crops are major staple foods globally and require innovative strategies to improve productivity.  Nigeria’s total grain production as at 2019 stood at 19.1 million tonnes, of which 11 million tonnes were corn and 6.5 million tonnes were sorghum.  Among this, total imports were 5.6 million tonnes, with rice alone constituting 3.8 million tonnes, of which 3 million tonnes valued at $1.2 billion were imported from other countries.  The Nigerian government recently imposed a 70% tariff and a levy on sea-imported rice, with a total import ban on land borders.  Nigerian farmers are also faced with the increasing cost of fertilizer and agrochemicals.  Therefore, formulating the best alternative to chemical fertilizers in terms of cost implications, environmental stability, and increased production rates will greatly enhance agricultural production in Nigeria.  The Nigerian government has opened many opportunities for farmers, which need to be complemented by sustainable research outputs.  Plant Growth-Promoting Rhizobacteria (PGPR) are beneficial rhizosphere bacteria that stimulate plant growth through direct and indirect mechanisms, including nitrogen fixation, phosphate solubilization, phytohormone production, siderophore secretion, pathogen suppression, and enhanced stress tolerance.  Recent studies indicate that microbial consortia comprising compatible PGPR strains often outperform single-strain inoculants due to synergistic interactions and multifunctional benefits.  The PGPR consortia have been reported to improve germination, root architecture, nutrient uptake, biomass accumulation, drought tolerance, grain yield, and soil health in cereal crops.  The adoption of well-formulated PGPR consortia offers a sustainable pathway to enhance cereal productivity while reducing dependence on chemical fertilizers.

Use of beneficial microorganisms in bean cultivation: strategies employed to increase productivity