Abstract
Ethyl formate (EF) is an environmentally friendly fumigant with strong potential as a methyl bromide (MB) alternative for pre-export quarantine disinfestation of agricultural produce. This study evaluated the synergistic effect of EF combined with 10 % carbon dioxide (CO₂) to enhance penetration and toxicity against Pseudococcus jackbeardsleyi in pineapple. Insect mortality was significantly influenced by EF concentration, treatment temperature, and developmental stage. At 25 °C, fumigation with 60 mg L−1 EF + 10 % CO₂ for 3 h achieved 99.9968 % mortality of the most tolerant stage. Comparable efficacy was obtained at 20 °C and 15 °C with 90 mg L−1 and 110 mg L−1 EF, respectively, representing an approximate 30 % reduction in EF concentration compared to EF alone. Large-scale confirmatory trials validated complete control of over 100,000 individuals at each temperature. Post-fumigation assessments showed no significant differences in fruit firmness, weight loss, total soluble solids (TSS), or titratable acidity (TA) during cold storage. EF-alone treatments, however, led to elevated respiration rates and greater color variation (ΔE) during shelf-life, while EF + CO₂ mitigated these effects. The combined treatment effectively stabilized physiological and visual quality. These findings indicate that EF + 10 % CO₂ is a highly effective phytosanitary treatment for P. jackbeardsleyi in pineapple, ensuring both quarantine security and postharvest quality. This strategy enables rapid and shelf-life-preserving pest control for fresh produce, supporting safer and more sustainable export practices.
