Effect of Varying Concentration of Nickel and Cobalt on the Plant Growth and Yield of Chickpea

A pot experiment was conducted to evaluate the sensitivity of chickpea, Cicer arietinum cv. T-3 to nickel and cobalt at 0, 10, 50, 100, 200 and 400 ppm concentrations. The bacterized seeds of chickpea were sown in 1 5 cm clay pots containing 1.5 kg steam sterilized soil. Before the sowing 550 ml metal solution of different concentrations was added per pot. Nickel and cobalt at the higher concentrations (100-400 ppm) were found injurious to chickpea. Seed germination, plant growth and biomass production were adversely affected. Root nodulation was suppressed and number of functional nodules appreciably decreased. Leaf chlorophyll contents were greatly reduced. These adverse impacts reflected in reduced yield of the plants. Nickel was apparently more harmful than cobalt to chickpea. The study suggests that cultivation of crops like chickpea in metal polluted soils should be avoided or appropriate control measures be adopted to maintain the heavy metal content of the soil below the damage threshold levels, which was found to be 10 ppm Ni and 50 ppm Co for chickpea