PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

This study was conducted to investigate the growth of two Opuntia ficus-indica varieties (var. inermis and var. Mill) in eleven geographical sites in the southwestern region of Saudi Arabia. Selected spectral vegetation indices (VIs) were used to identify suitable production sites for each variety. The results showed significant variations between the studied sites for both varieties. The best growth performance of the inermis variety was at Thaqeef Canal site, as evidenced by the highest values ​​of the Normalised Difference Water Index (NDWI, 0.477), Normalised Difference Vegetation Index (NDVI, 0.553) and the Green Normalised Difference Vegetation Index (GNDVI, 0.392), and the second highest value of the Soil Adjusted Vegetation Index (SAV, 0.392) compared to other sites. While the moderate growth performance of the var. Mill was at the Bani Saad site compared to other sites, as indicated by the values ​​of NDVI (0.575), SAVI (0.428), and GNDVI (0.408). A land suitability analysis focusing on site-variety interactions was conducted using the Analytical Hierarchy Process (AHP). The results indicated that Thaqeef Canal and Al-Shifa were the most suitable sites for the growth of both Opuntia ficus-indica varieties. Other sites considered highly suitable for growing the variety inermis include Al-hada, Wadi Muharrm and Sayyadah. While Baqran Village, Al-Thumalah farm, and Al-Thumalah were considered highly suitable for growing the variety of Mill. The results of this study provide a good basis for future studies aimed at improving agricultural practices and decision-making related to the production of Opuntia ficus-indica in the southwestern region of Saudi Arabia.