Relationship Between Residue Of Acetamiprid In The Cabbage Leaves And Activity Against Aphids With Two Applications

Acetamiprid is the main kind of insecticide for controlling aphids, which is the pharmacy of strong aspiration for application of soil or roots, but are mainly used in China by spraying. As a result of the drawbacks of the use of spraying are as follows: First, it lacks target specificity and wastes pesticide; Second, it causes environmental pollution; Third, it is used inconveniently and must be added water when spraying; Fourth, it harms non-target organism. But it avoids these drawbacks when acetamiprid is used by root pouring , in the light of this, this article is intended to aphids as target insects, because the aphids have provideded a serious threat to agricultural production. By comparing the two different application methods such as spraying and root pouring methods of using acetamiprid, combined with the residual state in the crop and the control effect of the test insects to investigate the relevance of the"bio-extraction"and the biological effectiveness of acetamiprid in order to provide the theoretical basis for the best use of methods and preparation of suitable formulations. Most residual analysis of acetamiprid are used by gas chromatography analysis, using high-performance liquid chromatography analysis adds a new option for the residual analysis of acetamiprid . The results could be summarized as follows:1. The persistence of acetamiprid on aphids extended with the spraying concentration(10-30mg/L) increasing, but its DT50 on leaf surface decreased; the effect of acetamiprid got better and better in 1-7 days after spraying, but the control effect got worse in 7-21 days. The residues of acetamiprid reduced gradually day by day.2. The control effect of acetamiprid got better and better the concentration (10-30mg/L) increasing by root pouring, both dynamic of effect and depletion of residue have the same trend in different concentration, which increased in 1-10days after root pouring, and decreased in 10-21days after applying acetamiprid by root pouring.3. Comparing the residues of the insecticide acetamiprid in the cabbage and the control effect to aphids by applying the two different application methods such as spraying and root pouring methods with the same concentration. For example, the concentration of acetamiprid is 30mg/l, the results showed that the residues of the acetamiprid in the cabbage was 12.81 mg/kg at 1d after spraying and the residues was only 2.48 mg/kg at 21d after spraying. However, the residues of the insecticide in the cabbage was 0.80 mg/kg at 1d after root pouring and the maxium residue was 4.60mg/kg at 10d after root pouring, then decreased gradually and the compound residue was arrived at 1.40 mg/kg at 21d after treating only one time using root pouring method. The results showed that the persistent period applied with root pouring was about 10 days longer than spraying method if the insecticide, acetamiprid, was used against the cabbage aphids. Meanwhile, the control effect to cabbage aphids was obviously different according to the different methods that is that the short-term control effect (within 7d) adopting spraying was much better than root pouring method, but the persistent bio-effect of spraying was much more shorter. The control effect was reduced evidently after 7d for spraying method use. On the other hand, at the same time the control effect to aphids always kept above 67% if adopting the root pouring method within 7d to 21d when the results were investigated.4. Both the residues of the acetamiprid in the cabbage and the control effect to aphids by applying the two different application methods such as spraying and root pouring methods have the same trend in different concentration.