|Michels, jr., Gerald|
|Elliott, Norman - Norm|
Submitted to: Turkish Journal of Agriculture and Forestry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/22/2006
Publication Date: 9/22/2006
Citation: Mirik, M., Michels, Jr., G.J., Kassymzhanova, S., Elliott, N.C., Catana, V. 2006. Spectral sensing of aphid (Hemiptera: Aphididae) density using field spectrometry and radiometry. Turkish Journal of Agriculture and Forestry. 30:421-428. Interpretive Summary: The greenbug and bird cherry-oat aphid are serious insect pests of wheat and other small grain crops. Greenbug and bird cherry-oat aphid infestation in crops is unpredictable over space and time. Therefore, a repeatable and rapid method is necessary for monitoring wheat fields for the presence of crop damaging infestations of these pests. Remote sensing appears promising for the monitoring of aphid infestations in wheat. The present research examined the potential use of spectral data to quantify greenbug and bird cherry-oat aphid infestations. A multispectral ground radiometer and a hyperspectral handheld spectrometer were used to record the level of reflected sunlight light particular wavelength bands of the spectrum of solar radiation. We mathematically described the relationship between the reflectance of light in particular wavelength bands that were reflected from the wheat crop canopy to determine how sensitive they were to infestation by greenbugs and bird cherry-oat aphids. The overall conclusion of the study was that multispectral and hyperspectral remote sensing have potential for monitoring aphid infestations in winter wheat fields. This knowledge will help lead to cost effective methods for monitoring wheat fields for damaging aphid infestations.
Technical Abstract: The greenbug, Schizaphis graminum (Rondani), and bird cherry-oat aphid, Rhopalosiphum padi L., are aphid pests of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), sorghum (Sorghum bicolor L.), oat (Avena sativa L.), and other cereals worldwide. Greenbug and bird cherry-oat aphid infestation in crops is unpredictable over space and time. From these 2 aphids, greenbug infestation causes significant reduction in yield, and consequently large amounts of insecticides are used to control greenbug populations. Therefore, a repeatable and rapid method is necessary for monitoring aphid populations. Remote sensing appears promising for the monitoring of aphid density in crops. The present research examined the potential use of spectral data to quantify aphid density (greenbug and bird cherry-oat aphid) in 3 winter wheat field experiments and 1 greenhouse experiment. A multispectral ground radiometer and a hyperspectral handheld spectrometer were used to record reflectance data. In order to quantify the relationship between reflectance data and aphid density, 2 spectral indices were used in regression. The coefficients of determination (r2) ranged from 0.48 to 0.76 for the hyperspectral-derived index and from 0.43 to 0.67 for the multispectral derived index. The results indicate that multispectral and hyperspectral remote sensing appear functional to monitor aphid population density in production winter wheat fields.