Correlation study of spectral vegetation indices and agronomical ground truth observations in promising cotton cultivars

Abstract

An experiment was conducted during Kharif season of 2019 and 2020 to study response of promising cotton cultivars to nitrogen levels through aerial multispectral remote sensing. Results indicate cotton cultivar (hybrid) PKV-Hy-2-BG-II was found superior than cultivar (improved) AKH-9916 in terms of leaf area plant-1, sympodial branches plant-1, total dry matter accumulation plant-1, picked bolls plant-1, average boll weight, seed cotton yield plant-1, seed cotton yield and lint yield. However, higher cotton stalk and biological yields were obtained in cultivar AKH-9916. PKV-Hy-2-BG-II recorded higher seed cotton yield with the application of 5.0 t FYM + 120 kg N ha-1, whereas AKH-9916 recorded higher seed cotton yield with the application of 5.0 t FYM + 90 kg N ha-1. Higher cotton stalk and biological yields were obtained in AKH-9916 with the application of 5.0 t FYM + 90 kg N ha-1. Spectral vegetation indices such as BNDVI, GNDVI and NDVI have potential to distinguish varietal differences as these indices recorded higher values for cultivar AKH-9916 than cultivar PKV-Hy-2-BG-II throughout the crop growth period. Spectral vegetation indices viz; BNDI, GNDVI and NDVI had potential to detect the status of cotton growth and changes in yield attributes while none of the SVIs showed any type of correlation with seed cotton yield ha-1 means these SVIs were failure to predict seed cotton yield ha-1.