Economic injury level for the silverleaf whitefly (Bemisia argentifolii Bellows & Perring) on tomato under nethouse
Date Issued
2005
Date
2005
Author(s)
Liu, Tai-shan
DOI
zh-TW
Abstract
This study was to establish an economic injury level for the silverleaf whitefly on tomato cultivated under nethouse, so as to reduce insecticidal applications. Experiments were conducted at the nethouses in Taoyuan District Agricultural Research and Extension Station with Asveg #4 toamto. Preliminary samplings were taken from April 26 to June 2, 2003 to analyze the vertical distribution of the silverleaf whitefly on tomato, and to estimate the optimal sample size via Taylor’s power model. Yield loss studies were conducted from November 27, 2003 to February 10, 2004. The population levels of the silverleaf whitefly were manipulated by the application of abamectin, and the control thresholds were set at 5 insects/leaf, 10 insects/leaf, 20 insects/leaf, and none as the check. Yield loss studies were conducted again from December 27, 2004 to April 6, 2005 by natural infestations of the silverleaf whitefly. All data collected were used to estimate the economic injury level by the EIL model, EIL = C/VID. The data collected from April 26 to June 2 in 2003 showed that individuals of silverleaf whitefly distributed at the height where the medium and old-age leaves blended. Sampling targets were setting at the 10th to 12th leaves counting down from the top of tomato plants with an optimal sample size 53 at 10 insects/leaf and 93 at 5 insects/leaf under C = 25%. The data collected from November 27, 2003 to February 2, 2004 showed that population density ranged from 4.3 to 19.73 insects/leaf, and the yield ranged from 880.25 to 1044.54 g/plant. The
yield decrease rate was at 8.5537 g/insect, and the EIL was estimated at 7.91 insects/leaf. The data collected from December 27, 2004 to April 6, 2005 showed that population density ranged from 6.88 to 19.83 insects/leaf, and the yield ranged from 1184.06 to 1400.64 g/plant. The yield decreace rate was at 16.131 g/insect, and the EIL was estimated at 4.19 insects/leaf. We conclude that the tomato Asveg #4 could tolerate direct damage by low silverleaf whitefly and these tentatively set EILs need further appraisal for their practicability.
Subjects
番茄
銀葉粉蝨
經濟為害水平
防治基準
最適樣本數
產量損失
tomato
silverleaf whitefly
Bemisia argentifolii
economic injury level
control threshold
optimal sample size
yield loss
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R91632014-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):c5be424953f1b966f537f000b0406e16