BACKGROUND AND OBJECTIVES: Begomoviruses transmitted by whiteflies threaten chili production and create environmental-management dilemmas because control often increases pesticide reliance and encourages residue burning that degrades air quality and soil organic carbon. The study objectives were to align disease control with environmental safety by integrating molecular identification of the causal begomovirus with field documentation of production practices that influence ecological risk and biosecurity in purple-stem chili production in Karo, North Sumatra.METHODS: Field documentation recorded production choices that affect environmental outcomes, including seed sourcing, residue handling, crop rotation, nutrient regimes and pesticide practice, across 21 production units. Sixty symptomatic fruits were processed into twenty seed lots; seedlings raised under insect-proof conditions were screened by polymerase chain reaction using degenerate begomovirus primers. Positive amplicons were Sanger-sequenced and evaluated by sequence comparison and phylogenetic placement against global begomovirus datasets.FINDINGS: Molecular screening produced a single fragment of approximately 916 base pairs; sequence comparison placed the fragment within the Pepper yellow leaf curl virus group with nucleotide identity near 90–92 percent to Indonesian isolates. Field documentation (21 production units) showed predominant use of farmer-saved local seed (66.7 percent), a high rate of post-harvest rotation (76.2 percent), and universal sanitation practices reported by respondents (100 percent). Integrated nutrient management combining mineral fertilizer with compost or manure was the largest single fertilizer strategy (about 28 percent), while the most common fertilization frequency was approximately three applications per season (modal response 35 percent). Previous crop history on sampled plots was often potato or mixed vegetables (33.3 percent). CONCLUSION: The coexistence of resilience-building practices (rotation, sanitation, organic amendment) with biosecurity gaps (widespread informal seed use without molecular testing) identifies priority intervention points. Priority initiatives to reconcile crop health with environmental safety include mandatory molecular seed-health screening for seed lots intended for distribution, low-cost whitefly monitoring coupled with threshold-based integrated pest management to reduce prophylactic insecticide use, substitution of residue burning with composting to protect air quality and soil carbon, targeted soil testing prior to liming, and full genome sequencing with public deposition to strengthen regional surveillance and traceability
Tarigan et al. (Thu,) studied this question.