Effectivenessof High Levels of Carbon Dioxide and Modified Atmosphere Conditions on Insect Infestation Development in Three Dry Date Cultivars

Abstract

The study was carried out to evaluate two methods of controlling postharvest insect pests, firstly, it dealt with effects of high levels of carbon dioxide (>98%) for 48, 72, and 96 hours on insect infestation development in three Libyan date cultivars, Athwi, Deglet and Talees. Treatments were made in airtight conditions, after treatments, samples were kept at 26°C.The second method was modified atmosphere conditions at 10% CO₂ and 5% O₂ at 5°C and room temperature. All samples were monitored for 7 months, then examined to determine the infestation rates.. Results showed significant effects of CO₂ treatments on infestation at 0.05 level, 72 and 96 treatments were better, infestation percentages of 72h treatment were 8.42±2.91, (3.33%±2.9), (3.49%±3.05) for Athwi,Deglet and Talees, respectively. For 96h treatments means were (3.33%±2.9), (12.04%±0.76), (3.49%±3.05), for Athwi,Deglet and Talees, respectively.But 48h treatment infestation means were quite higher at (9.6%± 1.0), (16.2%±2.6) and (8.5%±3.6) Athwi,Deglet and Talees, respectively.However, the control treatmentshowed the highest infestation level at (10.8%±1.6), (19.5±.87) and (14.4%±1.5) for Athwi,Deglet and Talees, respectively. The MA treatments showed that MA treatment alone did not have significant effect on infestation, but temperature showed significant effect; low temperature combined with MA was more efficient. Infestation percentage at 5°C was 0.0 for Athwi, (3.3%±4.1) for Deglet and (8.4%±7.1) for Talees, compared with room temperature with infestation percentages of (16.75%±4.26) for Athwi, (14.19%±5.37) for Deglet and (28.29%±8.62) for Talees. The study showed the potential of using high CO₂ treatments for reducing insect infestation in dry dates during storage and the possibility of testing MA combinations and other cultivars.