Scholarlink

<p>The fall armyworm (<i>Spodoptera frugiperda</i> J.E. Smith) poses a major constraint to maize (<i>Zea mays</i> L.) production across sub-Saharan Africa. This study evaluated biochar-based microbial inoculants incorporating <i>Bacillus thuringiensis</i> (Bt), <i>Pseudomonas putida</i>, <i>Klebsiella variicola</i>, <i>Trichoderma</i> spp., and <i>Arbuscular mycorrhiza</i> for their efficacy in fall armyworm management and maize growth enhancement. Molecular identification confirmed the bacterial isolates used, with Bt exhibiting the strongest chitinase and protease activities. The in vitro bioassays demonstrated a concentration-dependent larval mortality, reaching 90.4 ± 2.3% at 10⁸ CFU mL⁻¹. Probit analysis revealed LC₅₀ and LT₅₀ values of 2.6 × 10⁷ CFU mL⁻¹ and 48.2&#xa0;h, respectively, indicating high virulence of Bt against <i>S. frugiperda</i> larvae., the Biochar + Bt treatment achieved 76.5 ± 3.1% larval mortality and reduced leaf area loss to 18.4 ± 2.2%, comparable to the chemical control Ampligo<sup>®</sup> (88.2 ± 2.6%). Field trials under natural infestation showed that NPK (50&#xa0;kg N ha⁻¹) + Mycorrhiza + Biochar + Bt (T₂) significantly improved plant height (184.6 ± 5.2&#xa0;cm), chlorophyll content (65.2 ± 2.8 SPAD units), and grain yield (3.74 ± 0.16 t ha⁻¹) relative to the untreated control (2.41 ± 0.11 t ha⁻¹; <i>p</i> &lt; 0.05). Chlorophyll accumulation and foliar damage were significantly affected by the treatments, with Mycorrhiza + Biochar + Bt producing the lowest mean foliar injury scores (2.0–2.3) under both spray and non-spray regimes. Principal component analysis (PC₁ = 22.4%, PC₂ = 9.8%) clustered integrated bioformulations with yield-related traits, distinguishing them from nutrient only or untreated controls. These findings demonstrated that biochar-based microbial consortia enhance maize productivity, chlorophyll retention, and pest suppression, offering a sustainable and environmentally sound alternative to chemical insecticides in integrated pest management (IPM).</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Entomopathogenic microbial potential in the management of fall armyworm, Spodoptera frugiperda (J. E. Smith) in maize production

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年4月4日

查看全文
  • Iwebaffa Amos Edet,
  • Oluwafolake Adenike Akinbode,
  • George Oluwadamilare Iwebafa,
  • Clement Gboyega Afolabi

摘要

The fall armyworm (Spodoptera frugiperda J.E. Smith) poses a major constraint to maize (Zea mays L.) production across sub-Saharan Africa. This study evaluated biochar-based microbial inoculants incorporating Bacillus thuringiensis (Bt), Pseudomonas putida, Klebsiella variicola, Trichoderma spp., and Arbuscular mycorrhiza for their efficacy in fall armyworm management and maize growth enhancement. Molecular identification confirmed the bacterial isolates used, with Bt exhibiting the strongest chitinase and protease activities. The in vitro bioassays demonstrated a concentration-dependent larval mortality, reaching 90.4 ± 2.3% at 10⁸ CFU mL⁻¹. Probit analysis revealed LC₅₀ and LT₅₀ values of 2.6 × 10⁷ CFU mL⁻¹ and 48.2 h, respectively, indicating high virulence of Bt against S. frugiperda larvae., the Biochar + Bt treatment achieved 76.5 ± 3.1% larval mortality and reduced leaf area loss to 18.4 ± 2.2%, comparable to the chemical control Ampligo® (88.2 ± 2.6%). Field trials under natural infestation showed that NPK (50 kg N ha⁻¹) + Mycorrhiza + Biochar + Bt (T₂) significantly improved plant height (184.6 ± 5.2 cm), chlorophyll content (65.2 ± 2.8 SPAD units), and grain yield (3.74 ± 0.16 t ha⁻¹) relative to the untreated control (2.41 ± 0.11 t ha⁻¹; p < 0.05). Chlorophyll accumulation and foliar damage were significantly affected by the treatments, with Mycorrhiza + Biochar + Bt producing the lowest mean foliar injury scores (2.0–2.3) under both spray and non-spray regimes. Principal component analysis (PC₁ = 22.4%, PC₂ = 9.8%) clustered integrated bioformulations with yield-related traits, distinguishing them from nutrient only or untreated controls. These findings demonstrated that biochar-based microbial consortia enhance maize productivity, chlorophyll retention, and pest suppression, offering a sustainable and environmentally sound alternative to chemical insecticides in integrated pest management (IPM).