TREND ASSESSMENT OF CROP VIGOUR IN APPLE ORCHARDS USING TIME SERIES HIGH RESOLUTION SATELLITE DATA

摘要

Himachal is known as the apple state of India and covers nearly 49 per cent of the total area under fruit crop and 87 per cent of the total fruit production. Though area under apple orchards is growing, the present orchards are not able to meet the requirements of the country. Many orchards have become uneconomic and require rejuvenation practices in order to boost their economic yield. Remote sensing has played a vital role in assessment of orchard inventories in India and around the globe. However, very few studies have been directed in the area that utilizes remote sensing as a tool to keep a track of orchards to be considered for rejuvenation. The present study was conducted in Shimla district of Himachal Pradesh, in an effort to identify such orchards. Apple area was identified using supervised classification of RESOURCESAT-2 LISS IV data (~5 m spatial resolution). L1SS III data (~23 m resolution) from RESOURCESAT 1 and 2 over past 10 years (2005 - 2015) were used to study the trend of vigour of the apple orchards. It was done by using regression analysis of the NDV1 of the 10 years data against time represented by the years. Apple orchards of Shimla were characterized based on the analysis. Steady decline in the trend in vigour of apple orchards can indicate need of rejuvenation practices in those areas. But in Shimla, such areas constitute very negligible areas. The result is also validated by the ground observation that the apple farmers take exceptionally good care of their crop. Future scope of studies include impact of global warming, shift in suitable growing degree days and unconventional pest-disease effects. The study can be used to delineate areas requiring rejuvenation practices in other study areas and also for other crops like mango.