The search for effective and environmentally sustainable bioherbicides is a key objective in integrated weed management. This study evaluated the herbicidal potential of bergamot ( Citrus bergamia ) juice, a by-product of the essential oil industry, based on its high acetic acid content. Field experiments were conducted using a randomized complete block design to test five application rates (1,500, 1,200, 900, 600, and 300 L ha ^-1 ) on two contrasting weed communities: young regrowth (one week after mowing) and established weeds (four months after mowing). Efficacy was assessed over 60 days using the Henderson-Tilton formula and the European Weed Research Council (EWRC) rating scale. Soil pH was analyzed post-trial to detect acidification. A central finding was the stark contrast in efficacy based on weed growth stage. On established weeds, the rates of 1,500 L ha ^-1 and 900 L ha ^-1 provided the best control, with a residual activity of 30-45 days and efficacy >90% for up to 45 Days After Application (DAA). In sharp contrast, the treatment was largely ineffective on young regrowth, with even the highest doses providing only transient control that declined to very poor efficacy (≤31%) by 60 DAA. Results demonstrated that bergamot juice provided effective control of a broad spectrum of broadleaf weeds, including Phyllanthus amarus and Ageratum conyzoides , but showed poor efficacy against several grass species, particularly Paspalum dilatatum . Critically, no significant or consistent changes in soil pH were detected following application. The findings confirm that bergamot juice is a viable contact bioherbicide for managing established broadleaf weeds without impacting soil acidity but is not suitable for controlling young regrowth. Further research is needed to optimize application strategies, determine its economic feasibility, and fully elucidate its efficacy spectrum for commercial adoption.

This study evaluated the antifungal activity of plant extracts against Phytophthora infestans, the causal agent of tomato late blight. It was conducted in an insect-proof high tunnel using a randomized complete block design with three replicates. Treatments included aqueous garlic extract (0.2 g/mL), carapa oil (12% (v/v)) and neem oil (20% (v/v)), mancozeb 80 WP-based fungicide (5 g/L), and the untreated control. The biopesticides were applied once a week, while the chemical fungicide was applied once a fortnight. Applications were done before or after inoculation with 3×105 zoospores/mL of the pathogen. Recorded disease incidence varied from 50-100% for ancozeb to neem oil for preventive treatments and 100% for curative treatments. There was no significant difference in the severity of symptoms between aqueous garlic extract and mancozeb. The severity index ranged from 13.33 to 17.22% before inoculation to 20.0 to 25.0% after inoculation at the fruiting stage. The severity index of the untreated control was 58.34%. However, the net potential yield after inoculation with mancozeb (8.08 t/ha) was higher than that obtained with aqueous garlic extract (6.56 t/ha), carapa oil (4.95 t/ha), and neem oil (4.66 t/ha) compared to 4.55 t/ha for the untreated control. Hence, aqueous garlic extract can be used in integrated tomato late blight control programs.

Crop protection against pests and diseases remains a critical challenge for sustainable agricultural production, particularly in tropical regions. This study investigated the phytochemical composition and antioxidant properties of leaf extracts from Carica papaya and Urtica dioica cultivated in Côte d'Ivoire, aiming to assess their potential as natural biopesticides. Phytochemical screening revealed the presence of polyphenols, flavonoids, tannins, alkaloids, sterols, and polyterpenes in both species. Quantitative analyses showed significantly high contents of total polyphenols (158.8 to 176.9 mg GAE/g dry matter) and flavonoids (152.7 to 153.8 mg QE/g dry matter). Antioxidant activities evaluated by DPPH and ABTS assays highlighted strong free radical scavenging capacity, especially in Urtica dioica extracts. The bioactive secondary metabolites identified are known for their antimicrobial, antifungal, and insecticidal effects, supporting their application in integrated pest management. These findings underscore the potential of Carica papaya and Urtica dioica leaf extracts as eco-friendly, low-cost biopesticides to reduce reliance on synthetic chemicals and promote sustainable crop protection in Côte d'Ivoire.

Large-scale production of Bacillus thuringiensis, one of the most widely used biopesticides, is often limited by the high cost of conventional culture media. In this study, fermented cassava paste water (EFM), ripe mango pulp juice (CM), and cashew apple juice (JPC) were evaluated as alternative substrates for the liquid fermentation of B. thuringiensis var. kurstaki HD-1. Physicochemical analyses revealed acidic pH values and classified the substrates into two clusters: CM with high C/N ratios, organic matter, total sugars, and proteins, and EFM and JPC with lower C/N ratios and nutrient levels. Fermentation results indicated that JPC supported the highest biomass production (8.29 × 10¹³ CFU mL⁻¹), exceeding that in the standard Tryptone Soy Broth (TSB) medium. However, CM promoted the highest sporulation rate (1.46 × 10¹³ CFU mL⁻¹) and the greatest bioactive lipopeptides—iturins (102.2 mg L⁻¹) and surfactins (554.7 mg L⁻¹)—surpassing TSB. The antifungal activity of crude fermented CM, EFM, and TSB was evaluated against Sclerotium rolfsii. All samples significantly inhibited mycelial growth of the pathogen with no significant differences among substrates or concentrations tested. This study highlights the potential of B. thuringiensis-fermented agrowaste as a cost-effective, environmentally friendly biocontrol tool for Sclerotium rolfsii.