Effect of host‐plant resistance on economic injury levels for the sorghum midge, Contarinia sorghicola

Sharma, H C and Vidyasagar, P and Nwanze, K F (1993) Effect of host‐plant resistance on economic injury levels for the sorghum midge, Contarinia sorghicola. International Journal of Pest Management, 39 (4). pp. 435-444. ISSN 0967-0874

PDF - Published Version Restricted to ICRISAT users only Download (1MB) | Request a copy

Abstract

Sorghum midge, Contarinia sorghicola Coq. (Cecidomyiidae: Diptera), is the most important pest of grain sorghum worldwide. The effect of midge‐resistant cultivars on economic injury levels (EILs) for sorghum midge was studied on two midgeresistant (ICSV 197 and ICSV 745) and four commercial cultivars (CSH 1, CSH 5, ICSV 1 and ICSV 112). There was a linear relationship between midge density and percentage loss of grain in the midge‐susceptible cultivars CSH 1, CSH 5, and ICSV 112. However, there was only a marginal increase in midge damage with an increase in midge density in the midge‐resistant cultivars ICSV 197 and ICSV 745 while ICSV 1 showed a moderate increase in midge damage. Insect density‐damage relationships were better correlated when the cultivars were infested four times with a range of midge densities (5–40 midges/panicle) than with single infestations. Regression coefficient (b‐value) and coefficient of determination (R2%) increased with number of infestations and insect density in the midge‐susceptible cultivars. EILs based on four infestations (across Infestation levels) were 0.1–0.2 midges/ panicle for the commercial cultivars ICSV 1, ICSV 112, and CSH 1, and 25 and 33 midges for the midge‐resistant cultivars ICSV 197 and ICSV 745, respectively. EILs at 40 midges/panicle (across number of infestations) were: 0.2 midges/panicle for CSH 1, ICSV 1, and ICSV 112 compared with 6.7 midges for ICSV 745, and 100 midges for ICSV 197. Economic injury levels for sorghum midge therefore differ with plant resistance, insect densities, and the number of days for which the panicles are exposed to the midge flies. Panicles infested with a range of insect densities, and for three to four days give a reliable estimate of EILs for sorghum midge. It is important to determine EILs for resistant and susceptible cultivars for appropriate pest management decisions.

Item Type:	Article
Divisions:	UNSPECIFIED
CRP:	UNSPECIFIED
Uncontrolled Keywords:	plant resistance, economic injury level, sorghum midge, Contarinia sorghicola
Subjects:	Mandate crops > Sorghum
Depositing User:	Mr Charan Sai Ch
Date Deposited:	24 Oct 2011 11:56
Last Modified:	24 Oct 2011 11:56
URI:	http://oar.icrisat.org/id/eprint/3149
Official URL:	http://dx.doi.org/10.1080/09670879309371836
Projects:	UNSPECIFIED
Funders:	UNSPECIFIED
Acknowledgement:	UNSPECIFIED
Links:	Author

View Statistics

Actions (login required)

View Item