Jurnal Hama dan Penyakit Tumbuhan Tropika

Pheromone-based monitoring and population dynamics of Spodoptera frungiperda: implications for maize IPM in Lampung Province, Indonesia

2026-01-19T03:56:39+00:00

Spodoptera frugiperda is a major pest of maize, capable of causing damage throughout all crop growth stages. This study evaluated the use of sex pheromone traps to monitor adult male populations of S. frugiperda, characterize population dynamics during maize growth, and determine optimal trap density under field conditions. A trap density experiment was conducted using four pheromone trap densities (10, 20, 30, and 40 trap/ha⁻¹), each replicated five times. Adult moth captures were recorded at 7-day intervals from trap installation until harvest. In a separate assessment, the intensity of leaf and ear damage was compared between maize plots equipped with pheromone traps and conventional plots without pheromone deployment. Adult capture data revealed clear population fluctuations, with peak abundance occurring during the early vegetative stage of maize, followed by a gradual decline toward harvest. Increasing trap density significantly increased the number of male moths captured, indicating a density-dependent response to pheromone deployment. Maize plots with pheromone traps consistently exhibited lower leaf and ear damage than conventional plots, demonstrating a strong association between reduced adult populations and decreased crop injury. These results indicate that pheromone traps are effective tools for monitoring S. frugiperda populations and for identifying critical intervention periods within an integrated pest management (IPM) framework. While primarily serving as monitoring devices, higher trap densities also showed potential to reduce mating success when deployed over sufficiently large areas. The species-specific nature of pheromone traps further supports environmentally sustainable pest management by minimizing non-target effects.

First report of Fusarium incarnatum causing fruit rot of chili pepper in Indonesia

2025-10-23T07:16:13+00:00

Chili pepper (Capsicum annuum L.) is a widely cultivated horticultural crop with significant potential as an export commodity. Fruit rot of chili pepper was recorded in Lubuk Cuik village, North Sumatra Province, Indonesia. One hundred and fifty symptomatic fruits were randomly collected from four locations using purposive random sampling. Fungal colonies were isolated from infected fruits until pure cultures were obtained. Pure colonies observed for macroscopic examination exhibited abundant, dense white aerial mycelia with a brown–yellowish base. Microscopic observations revealed numerous long and slender macroconidia, 3–5 septate, with a curved shape and tapering ends. Microconidia were rare, pyriform to obovate in shape, and mostly 0–1 septate. Chlamydospores were thick-walled, intercalary, globose, and produced singly or in chains. Molecular identification was performed using the internal transcribed spacer (ITS) and translation elongation factor (TEF-1α) regions. The pathogenicity of the eight Fusarium incarnatum isolates was tested twice. The morphological characteristics, phylogenetic analysis, and pathogenicity assay confirmed that all isolates were consistent with Fusarium incarnatum. This study represents the first confirmed report of F. incarnatum causing fruit rot of chili pepper in Indonesia.

Enhanced nematicidal potential of MnCl2-fortified Bacillus sp. cell-free supernatant against Meloidogyne incognita

2025-09-30T04:23:45+00:00

Meloidogyne incognita causes major yield losses, underscoring the need for sustainable control strategies. This study is the first to demonstrate that micronutrient fortification and pH modulation of Bacillus sp. SK07 cultures enhance the nematicidal activity of their cell-free supernatant (CFS) and alter metabolite composition. Bacillus sp. SK07 was cultured in Nutrient Broth supplemented with MnCl₂ at 0, 50, or 75 ppm, with pH adjusted to 6 or 8. A 10% (v/v) CFS was evaluated in vitro against eggs and second-stage juveniles (J2) over 7 days using a completely randomized design with five treatments and five replicates. The most effective treatment—50 ppm MnCl₂ at pH 8—resulted in 96.4% egg-hatch inhibition and 63.6% J2 mortality at 168 hours, significantly higher than the unfortified control (91.8% and 49.4%, respectively). Chemical analysis revealed substantial changes in metabolite composition: unfortified cultures exhibited 9 peaks, whereas the optimized treatment produced 27 peaks, indicating increased chemical diversity. Several bioactive compounds, including fatty acid derivatives and aromatic esters, were identified. These compounds belong to diverse chemical classes such as acids, esters, alcohols, and hydrocarbons, many of which are known for their nematicidal activity. These findings demonstrate that MnCl₂ fortification at pH 8 effectively enhanced the bioactivity of Bacillus sp. SK07, offering a promising and sustainable approach for managing M. incognita.

First Report of Atherigona orientalis (Diptera: Muscidae) infesting Capsicum annuum in West Sumatra, Indonesia confirmed by COI barcoding

2025-11-28T04:56:16+00:00

Accurate identification of pest species is fundamental to the development of effective integrated pest management (IPM) strategies. This study presents the first molecular identification of the dominant fruit fly species infesting chili (Capsicum annuum L.) in West Sumatra, Indonesia, using DNA barcoding of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Adult specimens were collected between October 2024 and March 2025, and COI-specific primers were used to amplify the genomic DNA extracted from adult tissues. The resulting ~685 bp sequences showed 99.0–99.4% similarity and 96–100% query coverage with reference sequences of Atherigona orientalis (e.g., accession codes PQ483146.1, PQ483144.1, EU627707.1) based on BLASTn analysis. Phylogenetic analysis using the Neighbor-Joining method further confirmed species-level identification by clustering the specimens within the A. orientalis clade with strong bootstrap support. This study provides the first molecular evidence of A. orientalis infestation in chili crops in West Sumatra. The findings offer new insights into the pest status of A. orientalis within chili agroecosystems and emphasize the need for targeted pest management strategies. Moreover, these results establish a valuable baseline for future studies on the host range, dispersal patterns, and seasonal dynamics of this emerging pest to support more effective mitigation planning.

Efficacy of phosphonic acid applied by spraying and seed treatment at various concentrations for controlling downy mildew disease in maize

2025-09-01T08:09:25+00:00

Downy mildew, caused by Peronosclerospora spp., is one of the major problems in maize cultivation. Several studies have reported the development of resistance in Peronosclerospora spp. to metalaxyl, which had previously been an effective control method for the disease. Other research suggests that the efficacy of phosphonic acid in controlling downy mildew in maize is inconsistent. The objective of this study was to evaluate the efficacy of seed treatment with phosphonic acid in controlling downy mildew in Bisi 18 maize. The treatments were arranged in a randomized block design with six replications. The observed variables included the incidence and severity of the disease, the area under the disease progress curve (AUDPC), maize yield, and the content of tannin and hydroquinone compounds in maize leaves. The results showed that both phosphonic acid applied by spraying and seed treatment significantly reduced the incidence and severity of downy mildew (P < 0.05). However, the concentrations of phosphonic acid used in seed treatment had no significant effect on the disease during 1–7 weeks after inoculation. Furthermore, all phosphonic acid treatments tended to increase the content of tannin and hydroquinone compounds in maize leaves, which should be confirm quantitatively.