Analysis of Optimum Growth Stages for Winter Crop Separability using Multi-Temporal NDVI Profiles in Vijapur Taluka, Gujarat State-India

Abstract

In the present study analysis of growth stages of different winter crops grown in Vijapur Taluka was carried for determining optimumgrowth period for crop separability using multi-temporal NDVI profiles. The multi-temporal Sentinel-2 multi-spectral data coveringstudy area for the winter crop period from November-2018 to March-2019 was analysed. The spectral behavior of wheat, cotton,potato, fennel and castor crops during active growth stages was studied and it was observed that the spectral response of these cropsis quite distinct. However, wheat and potato have almost matching spectral response during the month of January when wheat was atflag leaf to flowering stage and potato was at maximum vegetative growth stage. This suggests that, single-date Sentinel-2multispectral digital data of active vegetative growth stages of these two crops during the month of January is not adequate anduseful for unique discrimination of wheat and potato. The Normalized Difference Vegetation Index (NDVI) profiles of these majorwinter crops were generated to monitor and identify the optimum growth stages of the winter crops for their unique separability. Theresults indicated that, during second fortnight of February, wheat was at grain filling and milk stage and potato was at maximumvegetative stage with tuber maturity and at the same time other crops namely cotton, castor and fennel were at the maturity stages,have quite distinct NDVI values. During the period of second fortnight of February major winter crops with different growth stageshad quite distinct spectral behaviour. This indicates that the period of second fortnight of February is quite good and unique fordiscriminating these winter crops using single date satellite data.