Effects of ethyl formate, a posthavest fumigation controlling fruit surface insect pests, on mangosteen quality
Exporting fruits are usually treated with methyl bromide; an ozone depletion substance, as a quarantine measure for controlling fruit surface insect pests. To protect the ozone layer, the Montreal Protocol designed a treaty providing a timetable on which the production of several substances must be phased out and eventually eliminated. It is therefore necessary to seek an alternative for methyl bromide before the restriction in the year 2015. In our initial study the effect of ethyl formate on five insect pests, citriculus mealybug, Pseudococcus cryptus Hempel (Hemiptera: Pseudococcidae), scale insect (Coccus sp.) (Hemiptera: Coccidae), chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), black cocoa ant (Dolochoderus thoracicus Smith (Hymenoptera: Formicidae) and tropical tyrant ant, Iridomyrmex anceps (Roger) (Hymenoptera: Formicidae), ethyl formate (EF) has the potential to control these insect pests. In this study, ethyl formate, carbon dioxide (CO2), and ethyl formate in combination with CO2 were evaluated to determine their effects on fruit quality. In fruit quality assessment, fumigation of ethyl formate at 25, 50, 75 and 100 g m-3, for 1, 2, 3 and 4 h had no effect on the internal and external quality of mangosteen, whereas the application of ethyl formate at over 100 g m-3 adversely affected the quality. Calyx and stalk were shrived, dry and brown in colour. In addition, the peel colour changed to dark brown and became hardened. The fumigation of fruit with carbon dioxide, CO2, at 25, 50, 75 and 100% and ethyl formate at 25, 50, 75 and 100 g m-3 combined with CO2 of 50 and 100% for 1, 2, 3 and 4 h had no effect on internal and external fruit quality of mangosteen. Calyx and stalk remained green. Fruit color development was uniform. Furthermore, flesh and its odor of treated fruits were not different from untreated fruits.
Ormking, C. (2017). Effects of ethyl formate, a posthavest fumigation controlling fruit surface insect pests, on mangosteen quality. Acta Hortic. 1178, 155-160
fruit quality, carbon dioxide, postharvest insect pests