Preliminary Research On Controlled-atmosphere And Temperature Treatment Of Two Quarantine Pests On China Major Export Fruit

Controlled atmosphere Temperature Treatment is a newly kind of comprehensive quarantine treatments which combined controlled atmosphere with forced hot air treatment The shorter treat time makes it more rapidly than controlled atmosphere treatment alone.And lower treat temperature makes it more efficiently than forced hot air treatment alone.These advantages could reduce the hot damages to treated fruits and vegetables.Compared to methyl bromide fumigation technology,it is more safer for human and less polluted to environment.Bactrocera?Bactrocera?' dorsalis?Hendel?and Carposina sasakii Matsumura are important quarantine pests in international trade and are of vital importance to pome fruit and stone fruit in southern and northern China.These pests could widely infect fruits and vegetables with great reproductive capacity.Once introduced in an area,they could cause destructive damage to the local production of fruits and vegetables,reducing the quantity and quality.Since they would bring invaluable damage to the live and production and even to the whole industry economics,quarantine measures must be carried out to change the situation.In this study,quarantine treatment is combined by controlled atmosphere with forced-hot-air treatment against oriental fruit fly in orange and peach fruit borer in apple.There are three parts of the study:1.Test on the effect of O₂,CO₂,temperature and humidity on insecticidal effect of controlled atmospheres and temperature treatment,CATT is conducted under the enrironment of 42? to kill the eggs of oriental fruit fly?18h?.There are different groups of CATT with kinds of ratios of O₂/CO₂ and humidity.Analyzing the relationship between the mortality and the factors to determine the best combination of air ratio?temperature and humidity.Use the thermo dynamics model to analyze the relationship between he mortality and treatment period.The result shows that the best combination consists of 1%O₂+15%CO₂+RH90%.With the temperature of 42?,the lethal effect of CATT to eggs of oriental fruit fly is strengthened by the decreasing oxygen,increasing carbon dioxide and humidity.2.Treatment of infected fruits.Treat oranges which are infected by different stages?18h-eggs,1st instar,2nd instar,3rd instar?oriental fruit fly with the best group of CATT.Treat apples which are infected by different stages?2day-eggs,4day-eggs?1-3 instar,4-5 instar?C.sasakii too.The result shows that eggs and the 3rd instar larva of oriental fruit fly are 100%kill by the controlled atmosphere temperature treatment with the environment consists of 1%O₂?15%CO₂ and RH90%,which lasts for 30 minutes when the core temperature reached 42?.The most thermal tolerant instar of oriental fruit fly larvae is the 1st intar.At the same condition,the eggs and 4-5 instar larvae of peach fruit borer,which die after the treatment all,are less tolerant than the larvae of the 1-3 instar.During the treatment of 42?and 44? ith controlled atmosphere of 1%O₂+15%CO₂+ RH90%,which last for 60min and 30min after the core temperature reached the goal temperature respectly,all stages of oriental fruit fly in navel oranges and peach fruit borer in apples are killed completely.3.Effects of controlled atmosphere temperature treatment to the quality of oranges and apples.After controlled atmosphere with 1%O₂+15%CO₂+RH90%,which lasts 60 min after the core temperature reached 42?,the fruits are restored at 25? for 2 weeks as the shelf life to document for the effects on fruit quality?hardness,weight loss etc.?.The result showed that CATT merely affect the fruit quality.As the time goes by,the quality of controlled group and treated group of oranges and apples decreased.The weight loss increased day by day,less than 5%.The soluble solids and the acid decreased.The color of the fruit grow yellow.We also find that lower temperature?4 ??enrironment can delay the decreasing quality of orange.