INFLUENCE OF POST-HARVEST CHILLING TREATMENT ON CERATITIS CAPITATA AND ITS IMPACT ON PHYSICAL AND CHEMICAL PARAMETERS OF VALENCIA ORANGE

The Mediterranean fruit fly, Ceratitiscapitata (Wiedemann), is found in most tropical and subtropical areas ofthe world. Therefore, the aim of this study was to evaluate the chillingtreatment method to reduce the cooling time and the cost. Thisinvestigation evaluated post-harvest cooling treatmentat 1 and 2oC on the immature stages of C. capitata inValencia orange and the effect of these temperature degrees on certain physical and chemical parameters of Valenciaorange fruits. The result revealed that the mortalitypercentage of immature stages increased by exposure time. The egg recorded 100%mortality after 8 days of exposure at 1oC, whereas the time ofexposure was extended to reach 10-12 days in the case of larvalinstars. Cooling time was extended for the tested stages; egg stage andthe three larval instars to 10, 12, 14, and 14 days after post-treatment at 2oC,till the mortality reached 100%. The data clarified that the mortalitypercentage increased with decreasing the temperature and the exposure timewhich decreased by decreasing temperature in all immature stages. Thisinvestigation clarified that the third larval instar of C. capitata wasthe most tolerable in Valencia oranges. The results showed that 12 days wereenough time for killing all immature stages of C. capitata aftertreatment at 1oC and 14 days of exposure to cold treatment at 2oCin Valencia orange were sufficient to achieve this infestation. There are nosignificant differences in both physical (weight loss, color, and hardness) andchemical parameters (acidity and soluble solid) of Valencia orange fruitsexcept vitamin C.