Effects Of Substrate,temperature And Humidity On Three Pesticide Residues In Agaricus Bisporus

The output of edible fungi in China ranks first in the world,but it's serious that the problem of pesticide residues occurs from time to time,and restricted the healthy development of the industry and affected the import and export trade.Different cultivation patterns of edible fungi and the law of pesticide digestion in the environment are different,and the related basic research is weak.In this paper,taking the cultivation of Agaricus bisporus as an example,the degradation dynamics of imidacloprid,prochloraz and beta cypermethrin in different formulations of Agaricus bisporus cultivation media were studied,and it was revealed that the degradation of imidacloprid and prochloraz was affected by temperature and humidity,which provided theoretical support for the standard use of industrial Agaricus bisporus pesticide and the reasonable selection and use of culture medium.The main results of this study are as follows,(1)Ultra high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)was used for detection,and QuEChERS purification method was used for pretreatment.The average recoveries of these three pesticides were 74%?98%with RSD of 3.3%?12.6%at the addition level of 0.01?1 mg/kg.The average recoveries were 80%?96%with RSD of 1.6%?12.3%in culture medium,82%?93%with RSD of 4.3%?9.1%in fruiting body.The average recovery and RSD in this experiment are in line with the requirements of pesticide residue analysis.(2)The field simulation experiment of Agaricus bisporus was carried out under the condition of factory facility cultivation.The residues of imidacloprid,prochloraz and beta-cypermethrin in the soil and fruiting body of Agaricus bisporus were dynamically monitored by mixing the soil and material in the covering soil and culture medium respectively.The results showed that these three pesticides accorded with the first-order reaction kinetic equation,and the dissipation half-lives(DT50)of pesticides in different substrates has the same tendency as following:in the original casing soil ST 1>the coconut chaff soil ST 3>the plant ash soil ST 2,and in the compost CT 2>the compost CT 1.It was preliminarily revealed that the degradation of the three pesticides was related to organic carbon content,pH value,pesticide properties and physicochemical properties of culture materials.Three kinds of pesticides were detected in the three flush mushroom growing under different treatments,which proved that the pesticides in soil of Agaricus bisporus cultivation would migrate to the fruiting body,and the degradation rate in the compost was faster than that in casing soil.(3)The cultivation experiment of Agaricus bisporus was carried out under the indoor simulated experimental conditions,and the cultivation experiment was carried out in the artificial climate incubator.The digestion dynamics of imidacloprid and prochloraz under the influence of temperature and humidity in the cultivation of Agaricus bisporus were preliminarily explored.The results showed that the degradation of imidacloprid and prochloraz had the same trend in different temperature conditions,and the DT50 of pesticides became shorter when the temperature increased from 15?to 20?.Under different humidity conditions,the degradation of imidacloprid and Prochloraz in soil and culture media also showed the same trend.The humidity increased from 70%to 90%,and the half-life of pesticides became shorter.It was confirmed that the increase of temperature and humidity could promote the degradation of pesticide in Agaricus bisporus cultivation.