Experiment on the efficacy of 10% chlorothioline wettable powder in the treatment of tea leafhopper

Control effect of 10% chlorothioline wettable powder on tea leafhopper

Abstract: the field experiment showed that 10% chlorothioline wettable powder had a good control effect on tea leafhopper, and the control effect was still more than 80% after 14 days.

Key words: chlorothioline; tea green leafhopper; control effect

10% chlorothioline wettable powder is a nitromethylene internal absorption insecticide. The mechanism of chlorothioline is selective inhibition of nicotinic acetylcholinesterase receptor in insect nervous system and highly competitive binding with it, thus destroying the normal conduction of central nervous system. A field experiment was conducted in Yixing City, Jiangsu Province from 2001 to 2002. The results showed that 10% chlorothioline wettable powder had good control effect on tea green leafhopper.

1 materials and methods

1.1 medicament to be tested

10% chlorothioline wettable powder (active ingredient: imidaclothiz, Nantong Jiangshan Pesticide Chemical Co., Ltd.); 10% imidacloprid wettable powder (Nanjing first Pesticide Factory).

1.2 Control object tea small green leafhopper

The experiment consists of 3000, 4000, 5000 times liquid of 10% chlorothioline wettable powder, 4000 times liquid of 10% imidacloprid wettable powder, and water control. Cell area 33.3m2, random block arrangement, repeated 4 times, interval between treatments, and protective lines around. The experimental field is located in the tea farm of Shanggan Village, Zhangzhu, Yixing City, Jiangsu Province. The tea tree is 21 years old, the soil is clayey loess, the content of organic matter is medium, and the pH value is 6.5. The application time was July 5 in 2001 and June 26 in 2002. Water consumption is about 50kg/667m2, uniform spray.

1.4 contents and methods of investigation

The results were investigated before and 1, 3 and 7 days after treatment. methods the pot patting method was used to check 4 points in each plot, and 1 pot per point (0.5m2) to record the number of falling worms. Compared with the pre-drug base, the reduction rate of insect population was calculated, and then compared with the control area, the control effect was calculated.

2 results and analysis

The control effects of 3000, 4000 and 5000 times treatment of 10% chlorothioline wettable powder were 96.13%, 90.65% and 88.30% respectively, and there was no significant difference among treatments. 3 days after application, the control effects of 3000, 4000 and 5000 times of 10% chlorothioline wettable powder were 96.12%, 91.85% and 87.50%, respectively, and there was no significant difference between treatments. 7 days after application, the control effect of 3000 and 4000 times of chlorothioline wettable powder was 93.92% and 82.83%, respectively, and the difference between treatments was not significant, while that of 5000 times solution was 75.92%. In the experiment in 2002, the control effects of 3000, 4000 and 5000 times of 10% chlorothioline wettable powder were 93.83%, 93.41% and 89.69%, respectively, and there was no significant difference between treatments. 3 days after application, the control effects of 3000 and 4000 times of 10% chlorothioline wettable powder were 96.72%, 92.65% and 89.30%, respectively, compared with 3000 times. 7 days after application, the control effects of 3000, 4000 and 5000 times of chlorothioline wettable powder were 83.90,78.89 and 76.86%, respectively, and there was no significant difference between treatments.

2.2 after systematic observation on the safety of tea trees, there were no symptoms of drug damage in each treatment area, and the growth period and growth were the same as those in the control area, indicating that the test dose of 10% chlorothioline wettable powder was safe for tea trees.

3 summary and discussion

The results showed that 10% chlorothioline wettable powder had good control effect on tea small green leafhopper and had both quick effect and lasting effect on tea small green leafhopper. 3 000 × 4 000 liquid (equivalent to effective dose 25~33mg/kg) has a good control effect on tea leafhopper and is safe to tea trees.