Variable intensity sampling: developing operational plans for the green rice leafhopper in wet paddy ecosystem in Malaysia
A relatively new sampling scheme called the variable intensity sampling (VIS) has been proposed for a rice pest, the green leafhopper (GLH),Nephotettix spp. Taylor’s Power Law (TPL) coefficients a and b were used in developing the VIS plan. Population density estimations and decision making attribut...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Malaysian Agricultural Research and Development Institute (MARDI)
1998
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| Online Access: | http://psasir.upm.edu.my/id/eprint/48908/1/Variable%20intensity%20sampling%20developing%20operational%20plans%20for%20the%20green%20rice%20leafhopper%20in%20wet%20paddy%20ecosystem%20in%20Malaysia.pdf http://psasir.upm.edu.my/id/eprint/48908/ http://ejtafs.mardi.gov.my/index.php/publication/issues/archive/92-1998/volume-26-no1/639-260113 |
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| Institution: | Universiti Putra Malaysia |
| Language: | English |
| Summary: | A relatively new sampling scheme called the variable intensity sampling (VIS) has been proposed for a rice pest, the green leafhopper (GLH),Nephotettix spp. Taylor’s Power Law (TPL) coefficients a and b were used in developing the VIS plan. Population density estimations and decision making attributes were derived from data obtained from four experimental plots at Universiti Putra Malaysia for a sampling period of 73 days. Four sampling occasions were chosen for analysis. The data fit well the TPL and are represented as lns2 = 0.24 + 1.30lnx– (s2 = variance, x– = mean density). A precision level of 0.25 and an economic threshold of 2 hoppers/hill were selected in developing this plan. The average sample number required in VIS ranged from 13 to 48. The VIS-TABLE for sampling and the VIS-CHART for determining the required sample size for GLH are presented. |
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