Background: Annona muricata, or soursop, is a tropical plant known for antimicrobial and antiparasitic properties, widely used in traditional remedies. Extracts from leaves, seeds, and bark show activity against pathogens in humans and plants, making it a promising candidate for natural biopesticide development as safer alternatives to chemical controls. This study evaluates Annona muricata seed extracts as bio-fungicides against Cercospora leaf spot in okra under field conditions. Methods: Capillary gas chromatography and mass spectrometry (GC-MS) analyzed aqueous and organic (acetone, ethyl acetate, and methanol) extracts. Two okra varieties (V1 and V2) were tested in field trials during 2019 and 2020. Six treatments included control, synthetic fungicide (3.33 g/L), aqueous extract (33.33 g/L), and methanol, acetone, and ethyl acetate extracts (1:600 v/v). Disease incidence, severity, and yield were measured. Results: GC-MS identified eight antifungal compounds (hexadecanoic acid methyl ester, hexadecanoic acid ethyl ester, hexadecane, n-hexadecanoic acid, octadecanoic acid methyl ester, 9-octadecanoic acid ethyl ester, and 10-octadecadienoic acid (Z,Z)-methyl ester), though these were not directly tested in this study. The Cercospora incidence at 12 weeks after sowing was significantly reduced from 51.11 % and 47.82 % in control plots during 2019 and 2020, respectively, to 8.88 % and 6.64 % in plots treated with aqueous extract and 9.99 % and 9.76 % in plots treated with methanol extract. Yields were highest with aqueous extract (6.48 and 5.22 t/ha), outperforming methanol extract, synthetic fungicide, and control. Conclusion: Bio-fungicides from Annona muricata extracts offer environmentally friendly options for managing okra cercosporiosis

Sweet potato crops are severely threatened by nematodes of the genus Meloidogyne spp. and Fusarium sp. fungi, which are responsible for Fusarium wilt. Nematodes cause root and tuber deformities, as well as wilting of stems and leaves, while Fusarium wilt leads to rot, necrosis, and wilting. These two pests contribute to a significant reduction in yields and substantial losses of production. Control measures primarily rely on the use of chemicals, whose excessive use poses a threat to the environment and human health. This study aims to assess the tolerance of four sweet potato varieties treated with aqueous neem seed extract against combined attacks from nematodes and Fusarium spp. A completely randomized block design with four sweet potato varieties (V1: white variety from the center region (togologo); V2: white variety from Adamawa region (lambadidi); V3: Improved Yellow variety (IRAD 1112); V4: Yellow variety from the center region (Bété)) and four treatments (T0: non-inoculated varieties; T1: varieties inoculated with nematodes + Fusarium; T2: varieties inoculated with nematodes + Fusarium then treated with neem aqueous extract; T3: varieties inoculated with nematodes + Fusarium then treated with synthetic pesticides) was used in a greenhouse. Agro-morphological, epidemiological parameters, and biochemical resistance markers were evaluated. The results revealed that treatment with neem extract (T2) reduced severity rates by 60 to 80% in the different growing bags compared to treatment (T0), followed by treatment (T3). The highest yields were obtained in treatments T1 and T2 across all varieties. The Adamawa White variety (lambadidi) (V2) and the IRAD 1112 variety (V3) exhibited the highest yields with up to 7 t/ha in T3 treatment. The content of phenolic compounds, proteins, and the enzymatic activity of peroxidase were higher in sweet potato plants inoculated with Fusarium and treated with neem aqueous extract. Neem treatment showed strong protective potential in combating fungal diseases and nematodes affecting sweet potato.

This study evaluated the effectiveness of indigenous microorganism (IMO) in association with wheat bran and enhanced with NPK fertilizer, to suppress Fusarium wilt and Gummy stem blight and improve watermelon production. A split-plot experimental design with three watermelon varieties (V1: Kolosse; V2: Pinksweet; V3: Kaolack) and six treatments were used. Three cultivation periods were conducted with different treatment combinations. Experiment 1 and 2 which consisted of control, 30 g IMO, 38 g IMO , 46 g IMO, NPK + Fungicide, 38 g IMO + NPK. Experiment 3 were, based on previous results, IMO rate was increased; the six treatments included control, 50 g IMO, 150 g IMO, 250 g IMO, NPK + fungicide and 150 g IMO + NPK. Epidemiological parameters and morphological identification of two pathogens as well as agronomic parameters were assessed. The results revealed that in the first experiment, 46 g IMO reduced the disease incidence of Fusarium wilt by 23.29 % compare to the control; in the second campaign, no Fusarium wilt symptoms were observed in plants treated with 38 g IMO , 46 g IMO and the combination 38 g IMO +NPK. On the contrary, 30 g IMO increased the disease severity of Gummy stem blight by 44.41 % to 90.42 % compared to NPK + F followed by control. Morphological identification confirmed Fusarium oxysporum sp. and Stagonosporopsis sp. as the causal pathogens. Treatment 150 g IMO + NPK increased the weight of watermelon fruit by 89.30 % compared to control, followed by 250 g IMO. Kolosse variety exhibited the highest TSS in treatment combination with up to 10.40 ° Brix in experiment 3 followed by Pinksweet 10.23 ° Brix. This finding demonstrates that IMO bokashi represented a viable strategy for improving watermelon health and productivity.