TY - JOUR
T1 - Association of spectral reflectance indices with plant growth and lint yield in upland cotton
AU - Gutierrez, Mario
AU - Norton, Randall
AU - Thorp, Kelly R.
AU - Wang, Guangyao
PY - 2012/3
Y1 - 2012/3
N2 - Canopy reflectance plays an increasingly important role in crop management and yield prediction at large scale. The relationship of four spectral reflectance indices with cotton (Gossypium hirsutum L.) biomass, leaf area index (LAI), and crop yield were investigated using three cotton varieties and five N rates in the irrigated low desert in Arizona during the 2009 and 2010 growing seasons. Biomass, LAI, and canopy reflectance indices (normalized difference vegetation index [NDVI], simple ratio [SR], near-infrared index [NIR], and ratio vegetation index [RVI]) were determined at different growth stages. The commonly used NDVI and the other three canopy reflectance indices explained over 87% variation in cotton biomass (all R 2 > 0.87) and LAI (R 2 > 0.93). Indices SR, NIR, and RVI all had higher coefficients of determination (R 2) compared to NDVI because these indices were not saturated at late growth stages. There was no significant relationship between lint yield and the spectral indices measured at early growth stages. However, the spectral indices determined at peak bloom showed significant correlations with lint yield. Indices SR, NIR, and RVI explained 56, 60, and 58% of variations in cotton lint yield, respectively, while NDVI only explained 47% of variation in lint yield. This study suggests canopy reflectance indices can be used to predict cotton lint yield at peak bloom and the accuracy of yield prediction can be significantly improved when SR, NIR, and RVI are used.
AB - Canopy reflectance plays an increasingly important role in crop management and yield prediction at large scale. The relationship of four spectral reflectance indices with cotton (Gossypium hirsutum L.) biomass, leaf area index (LAI), and crop yield were investigated using three cotton varieties and five N rates in the irrigated low desert in Arizona during the 2009 and 2010 growing seasons. Biomass, LAI, and canopy reflectance indices (normalized difference vegetation index [NDVI], simple ratio [SR], near-infrared index [NIR], and ratio vegetation index [RVI]) were determined at different growth stages. The commonly used NDVI and the other three canopy reflectance indices explained over 87% variation in cotton biomass (all R 2 > 0.87) and LAI (R 2 > 0.93). Indices SR, NIR, and RVI all had higher coefficients of determination (R 2) compared to NDVI because these indices were not saturated at late growth stages. There was no significant relationship between lint yield and the spectral indices measured at early growth stages. However, the spectral indices determined at peak bloom showed significant correlations with lint yield. Indices SR, NIR, and RVI explained 56, 60, and 58% of variations in cotton lint yield, respectively, while NDVI only explained 47% of variation in lint yield. This study suggests canopy reflectance indices can be used to predict cotton lint yield at peak bloom and the accuracy of yield prediction can be significantly improved when SR, NIR, and RVI are used.
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U2 - 10.2135/cropsci2011.04.0222
DO - 10.2135/cropsci2011.04.0222
M3 - Article
AN - SCOPUS:84863137046
SN - 0011-183X
VL - 52
SP - 849
EP - 857
JO - Crop Science
JF - Crop Science
IS - 2
ER -