Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/15/2004
Publication Date: 11/7/2004
Citation: Riedell, W.E., Osborne, S.L., Hesler, L.S. 2004. Effect of insect pests and disease on oat crop canopy characteristics. Meeting Abstract. Annual Meeting, American Society of Agronomy, October 31-November 4, 2004, Seattle, WA.
Technical Abstract: Knowledge of how different insect species and plant disease affect small grain crop canopy reflectance may allow the use of remote sensing techniques to distinguish between insect and disease damage. Experimental objectives were to characterize canopy reflectance spectra of oats damaged by greenbugs (GB), Russian wheat aphids (RWA), and by barley yellow dwarf (BYD). Oat plants were infested with aphids or infected with barley yellow dwarf virus (BYDV) at the 3-leaf stage. Canopy temperature, chlorophyll, leaf area index, and canopy reflectance (350 to 1100 nm) were measured at the flag leaf stage. In both years of the study, leaf chlorophyll concentrations were less and canopy reflectance in the 600- to 650-nm range was greater (compared with control) in oat canopies infected with BYDV. In the second year of the study, canopy temperature was greater while canopy reflectance in the near infrared (750- to 900-nm) range was less in oat canopies that were infested with RWA or infected with BYDV. Stepwise regression analysis on reflectance data revealed multiple regression equations useful for predicting canopy temperature, chlorophyll, and yield in the second year of the study but not in first. Canopy characteristics and spectral reflectance differences between insect infestation damage and disease infection damage can be measured in oat crop canopies but these differences may not be consistent from one growing season to the next.