Investigation Of Insect Pests In The Chinese Cabbage Fields And Safety Evaluation Of Pests And Diseases Residues During Storage

Chinese cabbage is the largest amount of winter vegetables in northern China.Currently,it is also the vegetable with the largest planting area.In order to better adapt to the urban residents for the "basket" agricultural products "more fresh,more quality,more nutritious and pest-free" consumption of food requirements,more in the production of more emphasis on product quality improvement,green pollution-free vegetable cultivation The ratio increased year by year.But the amount of pests and diseases in the field and the amount of pests and diseases also increased.Therefore,based on the occurrence of pests in the growing season of Chinese cabbage,the investigation of the occurrence of pests in the growing period of Chinese cabbage and the investigation and safety assessment of the pests and diseases of winter pests and diseases were carried out in combination with the pests and diseases of winter Chinese cabbage.For the safety of Chinese cabbage production,but also for China's agricultural products,quality and safety supervision to provide a certain theoretical support and decisionmaking services.The main results are as follows:The data of the occurrence of Plutella xylostella in Chinese cabbage field were collected from 2005 to 2016,and the correlation analysis was made with meteorological factors.The analysis method was Random Forest.According to the results of the random forest model,we can conclude that the "average temperature" plays a major role in the occurrence of P.xylostella in the meteorological factors affecting the occurrence of P.xylostella.In addition,the "average relative humidity" on the occurrence of P.xylostella also played a role.According to the survey of Shandong Agricultural University in 2015,the incidence of pest infestation decreased gradually in October and September,and the rate of occurrence of Aphis gossypii increased with the decrease of temperature.Compared with ordinary cabbage,several common Chinese cabbage pests in the pollution-free cabbage on the occurrence of more serious,of which the most obvious aphid aphid.It was found that the main pests and diseases of Chinese cabbage during the storage period were: the storage pests were more likely to harm the quality of Chinese cabbage when the storage temperature was above 5 ?.The risk analysis model of pests and diseases of Chinese cabbage was established by quantifying the risk value of different kinds of pests and diseases.Using the mathematical model of pest and disease residue evaluation,it was concluded that the quality of Chinese cabbage pests and diseases had different effects on the quality of Chinese cabbage,The riskvalues of the Chinese cabbage soft rot lesion,Chinese cabbage black spot disease and the white feather disease were 0.68,1.26 and 0.24 respectively.The risk values of the aphids,Pieris rapae and Plutella xylostella were : 0.82,0.34,0.32.From the above data can be drawn,cabbage black spot disease on the shelf life of Chinese cabbage quality is moderate risk,while other pest residues for low risk.