Field efficacy test of 12% cypermethrin emulsion in water against litchi in stinkbug.

Litchi stinkbug is the main pest of litchi. Adults suck the juice of litchi buds, shoots, flowers and fruits. It has piercing and sucking mouthparts, which affects the growth of new shoots, or causes flower drop and fruit drop, which has a great impact on yield. In order to screen chemical pesticides suitable for production, we carried out this experiment with 12% cypermethrin emulsion in water in Hufeng litchi orchard in Huiwen town of our city on 20 12. The test results are reported as follows:

I. Materials and methods

1. test reagent

12% cypermethrin emulsion in water (product of Guangdong Dongguan Ruidefeng Biotechnology Co., Ltd.); 10% cypermethrin EC (product of Ling Pesticide Chemical Factory in Yangzhou City, Jiangsu Province).

Step 2 control the target

Litchi stinkbug

3. Experimental crops

Litchi (Princess laughs).

4. Meteorological conditions

During the test period, it turned cloudy and cloudy, and the average daily temperature was 25-28℃.

5. Experimental design

There are five treatments in the experiment: ① 12% cypermethrin EW 1000 times solution; ② 12% cypermethrin EW 1500 times solution; ③ 12% cypermethrin EW2000 times solution: ④ 10% cypermethrin EC 1500 times solution; ⑤CK (blank control, spraying water). Repeat 4 times, ***20 plots, every 3 plants are 1 plot, randomly arranged in blocks.

6. Testing and survey methods

The experiment was conducted in Hufeng Litchi Garden, Huiwen Town, Wenchang City. Litchi is 6 years old. On April 15, routine uniform spraying was carried out with Linong HD400 manual backpack sprayer. Before applying pesticide, the population base was investigated, and 2 plants were investigated in each plot, and the number of all adults in the crown was investigated. After application 1d, 3d and 7d, the number of remaining live insects on the plant was investigated, and the population decline rate and control effect were calculated. The control effect was analyzed by variance, and the differences between treatments were compared by DMRT method.

Second, the results and analysis

No phytotoxicity was found in the whole experiment.

The experimental results (attached table) show that the population decline rates of the three treatments (1d, 12% cypermethrin EW 1000 times, 1500 times and 2000 times) are 96.23%, 93./kloc-respectively. The reduction rate and control effect of the control agent 10% cypermethrin EC 1500 times solution were 86.74% and 87. 1 1% respectively. The results of variance analysis showed that the control effects of 12% cypermethrin EW 1000 times solution and 1500 times solution were higher than those of the control agent 10% cypermethrin EC 1500 times solution, and the difference reached a very significant level. The control effect of 1.2% cypermethrin EW was significantly different.

On the third day after application, the relative control effect of each treatment area was the highest, and the control effects of 12% cypermethrin EW 1000 times solution, 1500 times solution and 2000 times solution were 98.75%, 95.50% and 86.64% respectively, and the control drug was 65438+. The result of variance analysis is the same as that of 1d after taking the medicine.

On the 7th day after application, the population decline rates of three treatments (12% cypermethrin EW 1000 times solution, 1500 times solution and 2000 times solution) were 96.29%, 92.52% and 79.60% respectively, and the control effects were 97.03% respectively. The result of variance analysis is also the same as 1d after taking the medicine.

Three. Conclusion and discussion

Using 12% cypermethrin emulsion in water to control stinkbug scale insects of litchi has an ideal control effect, the highest relative control effect can reach 98.75%, and the duration is long. After 7 days, the population decline rate is still above 96%. And it is safe for litchi in the concentration range of this experiment, so it can be popularized and applied in litchi producing areas. It is suitable for the peak period of adult spawning and the whole incubation period of nymphs, with the concentration of 65,438+0,000-65,438+0,500 times, and the use interval of 7-65,438+05d, and the application is stopped before harvesting.