93 

natural plant extracts from Tea Seed Kernel and Sapindus to prevent Pomacea 
Canaliculata. By using pH value as measurement basis; five concentrations including 0.2 
g, 1 g, 10 g, 50 g and 100 g on indoor constant temperature test and outdoor exposure test 
were determined under different temperatures. Result of experiments showed that Tea 
Seed Kernel is an acidic substance as the dose increases 0.2 g to 100 g, and the pH value 
was 4 and 4.5 in indoor constant temperature test and outdoor exposure test; Sapindus 
rendered weak acid as the dose increases 0.2 g to 100 g, and the pH value was 5.3 and 6 
in indoor constant temperature test and outdoor exposure test. Tea Seed Kernel and 
Sapindus was positive correlated with pH value and temperature, both of these substances 
have significant effectiveness in killing Pomacea Canaliculata. Concerning on 
environmental impact, Sapindus release weak acid in environment which is less 
threatening in soil and water, therefore Sapindus which has same effectiveness with Tea 
Seed Kernel was selected instead of Tea Seed Kernel as substrate to kill the Pomacea 
Canaliculata in paddy fields.

 

Keywords: Pomacea Canaliculata, Tea Seed Kernel, Sapindus, pHValue. 

 

 

 

(

Pomacea Canaliculata)

1979

19%

1981

1982

1985

1986

1987

1989

(1)

1982

(2)

1986

171,425 ha

19,980 

ha

3.76%

(3)

3,090

(1)

11.69

3.21%

 

10~50 

cm

2~45℃

北

(4)

151~773

250

7~9

4

7,000~9,000 

14~16

 

3~5

20℃

 

30℃

6

(2)

(5)