attached
Rubber (Hevea brasiliensis) is a valuable cash crop and the primary source of natural rubber. Ecophysiological and topographical
factors are main governing parameters in sustainable cultivation. Present study focused on application of satellite Remote
Sensing (RS) and Geographic Information techniques to determine suitable topographic factors for high productivity of rubber.
Dartonfield Estate in Kalutara, Sri Lanka was selected for the investigation. QuickBird high resolution satellite images were
used for RS analysis and 1:10000 scale topographic maps including field observations were used for modeling of topographic
characteristics. Chlorophyll content of rubber leaves was measured using SPAD-502 Chlorophyll meter. Relationship between
total leaf chlorophyll content and NDVI values was determined, and it was correlated with yield data.
NDVI vs Chlorophyll showed positive correlation (r2
> 0.5). Chlorophyll content of rubber leaves was slightly lower on top
of the ridges while higher on the southwestern slopes. The highest latex yield was on the high elevated ridges while the lowest
towards the bottom of the southwestern slopes. Therefore, hilly grounds are more suitable for rubber cultivation than flat ground
valley bottom.
