Studies On Four Pesticides Clearing Up Rule And Removal Technology On Chinese Cabbage

Chinese cabbage as the material is sprayed four kinds of pesticides when it has four leaves and one heart in order to proceed the study of non-public hazards vegetable ,looking for suitable usage and times of Dichlorvos, Omethoate , Depteret, Pirimicarb which are commonly used ,testing their safe partition period and the most valid pesticide detergent. Each pesticide has three different densities ,three different spraying- times and different applying fertilizer way .Six kinds of pesticide detergents are used after Chinese cabbage is harvested. The results indicate that firstly ,from repression of enzyme inhibition rate it can be seen that pesticide in Chinese cabbage that sprayed by Dichlorvos, Omethoate , Depteret, Pirimicarb all can reduce to the lowest limit in the examination. Pesticides in Chinese cabbage resolve most quickly in three days after the last time spraying and can attain the standard that safety usage in the third day(enzyme inhibition rate ≤30%). Pesticides in Chinese cabbage that sprayed one time resolves most quickly, and can attain the lowest standard during four days. That in Chinese cabbage that sprayed three times resolves the slowest and attain during six days. Chinese cabbage is sprayed Dichlorvos, Omethoate , Depteret, Pirimicarb of three different densities, with the same density and times. From the first to second day after spraying ,the enzyme inhibition rate increases with the increase of sprayed density,. It can be concluded that sprayed density affect the pesticide residue greatly, After sprayed by the three different density pesticide, Chinese cabbage can be eaten in the third day. after sprayed Dichlorvos, the plant-height and leaves-area in treatments with the same spraying density increase with the increase of spraying times ,but the leaf-area in treatment with 400 times liquid is an exception. The reason of this regulation has not been reported. Treatment sprayed Omethoate , Depteret, Pirimicarb do not follow this regular, which is to say that plant height and leaves area are not relative to the spraying-times. Fertilizing can increase the plant-height and leaf-area in the treatments of Dichlorvos, Omethoate , Depteret, Pirimicarb. Thirdly, it can be tested that after spraying Dichlorvos, Omethoate , Depteret and Pirimicarb different treatments have different influences on content of chlorophy11 in Chinese cabbage.With the same density it increases with the increase of spraying-times.As to the three treatments sprayed Dichlorvos content of chlorophy11 in Chinese cabbage with leaf using fertilizer is more than that all plants using Fertilizer and no- Fertilizer. As to the three treatments sprayed Omethoate , Depteret or Pirimicarb, content of chlorophy11 in Chinese cabbage with Fertilizer is more than that leaf using fertilizer and no using Fertilizer. Forthly,in the removal experiment ,it can be seen from the comparison of the six different methods that A14 has the best washing-result ,which to Dichlorvos comes to 35.8 percent.A17 has the poorest washing-result, which is only 7.5 percent. From the comparison of the six different methods that B13 has the best washing-result, which to omethoate comes to 16.8 percent.B14 has the poorest washing-result, which is only 0.2 percent. From the comparison of the six different methods that D16 has the best washing-result ,which to pirimicarb comes to 37.0 percent. Water has the poorest result.