A pot experiment was conducted with fourteen coarse textured alluvial soils (Typic Ustifluvents) to find suitable soil and plant tests of sulphur and their critical limits for potato. Dry matter yield of whole plant (shoot + tuber) and tuber in control on different soils variedfrom 69 to 105 and 62 to 102 per cent, respectively. 05 M NaHCO3 extractable SO4-S gave highest correlation (0.77**-0.94**) with all the plant responses. followed by Ca(H2PO4)2(500 ppm P), 0.1M LiCI. 0.15 per cent CaCl2 solution. IN NH4OAc and water. Critical limit of available SO4-S in soil was 155 and 10.5 mg kg−1for NaHCO3 and Ca(H2PO4)2 solution, respectively. whereas 6 mg kg−1for all other extractants. Critical limit of plant tests of S concentration. NIS and PIS ratios in potato leafat after 60 days of planting were 0.27 per cent, 14.0 and 1.01, respectively.
Potato, S in soil and leaf, response to S, critical limits
