Study On Technology Of Cryogenic Storage And Diseases Control During The Shelf Life Of Kiwifruit

Kiwi fruit (zhonghua Actinidia) has satisfying storability in most areas. But the storability of kiwi fruits from Zibo Shandong Province is poor, whether it is sprayed pesticides in the field or complied with the Organic Food Produce Standard. And it had soft rot disease after storage 30 days and the incidence rate is over 85% by using the current storage method, such as MA or CA.Therefore, the study was commissioned by the enterprise to research the storability of kiwi fruits at different site conditions and fruit cultivation methods. And the study researched the physiological and biochemical changes of the fruits at different temperatures, atmosphere, physiological agent or preservative treatment conditions. Moreover, the softening mechanism of kiwifruits was researched, the main pathogen was separated during the shelf lives and the better fungicide was selected.Firstly, the fruit storability experiment result showed that there is preservation effect on the fruit bagging pre-harvest, it improved the fruit storability and reduced shelf life rot disease. And the bag D-5 was the best treatment in the experiment. The firmness, the SSC content, the TA content and the decay rate was 8.30 kg cm-2,18.5%,0.96%,10.3% respectively after the storage of 150 days. Different temperatures experiment showed that 0℃ was the optimum temperature of long time storage. And the chilling injury temperature was-2℃. High concentration of CO2 will injury the fruit,5%CO2 was the optimum environment for kiwifruits, it can slow down the fruit aging rate.Secondly, the shelf life experiment showed that fruit shelf life was shortened with the extension of storage period. The shelf life of fruit which storage 50 days at 0℃ was more than 15 days, and it was similar to fresh fruit. While the fruits which storage 100 days was 12 days and storage 150 days was 9 days. The kiwi fruits’activity ofamylase, PG,PE and cellulase, which were stored for 50d at 0℃, reached peak during the shelf life, while the kiwi fruits’enzymes activities, which were stored for 100d and 150d, were decreasing during the shelf life and had not appeared peak.Moreover, five main pathogens were separated from the kiwi fruits. Through observe pathogens morphological by microscope confirmed that they were Phomopsis sp., Penicillium spp., Alternaria spp., Botrytis cinerea.and Macrophoma sp respectively. And the study confirmed that Phomopsis sp., Penicillium spp., Alternaria spp. were main pathogens during shelf life. The Phomopsis sp. will lead to fruit soft rot disease.Eventually,nine fungicides were selected for antagonistic activity against three main pathogen. Duojunling was best for antagonistic activity against main pathogens. The results showed that the bacteriostatic diameter on Phomopsis sp. was 44.0 mm, on Penicillium spp. was 45.0 mm and on Botrytis cinerea. was 42.0 mm by this fungicide. And the infection rates of kiwi fruits which was inoculates with Duojunling and Phomopsis sp.,Duojunling and Penicillium spp.,Duojunling and Botrytis cinerea.was 17.9%,22.5%,34.5% respectively.