Relationship between defoliation, canopy reflectance and pod yield in the peanut-late leafspot pathosystem

Nutter, F. W., Jr and Littrell, R.H. (1996) Relationship between defoliation, canopy reflectance and pod yield in the peanut-late leafspot pathosystem. Crop Protection, 15 (2). pp. 135-142.

[img] PDF - Published Version
Restricted to ICRISAT researchers only


Defoliation of groundnut (caused by Cercosporidium personatum [Mycosphaerella berkeleyi]), and reflected radiation (800 nm wavelength) of sunlight from groundnut canopies, were assessed weekly beginning c. 60 d after planting. Visual and reflectance assessments obtained with a hand-held, multispectral radiometer continued until 1 week prior to digging. Critical-point yield-loss models were developed using either percentage defoliation or percentage reflectance values as the independent variable and pod yield (kg/ha) as the dependent variable. Yield reductions in the 4 experiments ranged from 52.9 to 79.0%. Based upon coeff. of determination and the standard errors for predicted y-values (yield), the best critical-point models for either assessment method were obtained when groundnuts were assessed 2-3 weeks prior to digging. Critical point models using percentage reflectance data as the independent variable explained more of the variation in groundnut pod yield and had lower standard errors of the y-estimate than critical point models using percentage defoliation values as the independent variable. Percentage reflectance values explained 96.3-99.3% of the variation in biomass. It is concluded that measurements of healthy green leaf area (as estimated by percentage reflectance) have a better relationship with pod yield than defoliation based assessments.

Item Type: Article
Additional Information: SNNigam Collection
Uncontrolled Keywords: Arachis hypogaea; Cercosporidium personatum; crop loss; multispectral radiometry; remote sensing; yield loss modeling
Author Affiliation: Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA.
Subjects: Plant Protection
Divisions: Groundnut
Depositing User: Mr Balakrishna Garadasu
Date Deposited: 14 May 2013 04:29
Last Modified: 14 May 2013 04:29
Official URL:

Actions (login required)

View Item View Item