Who developed the DTPA tests for available soil micronutrients

Answer: Option B

The DTPA (diethylene triamine penta acetic acid) test is to test soil micronutrients and identifies near-neutral and calcareous soils with insufficient available Fe, Zn, Mn and Cu for maximum yields of crops. It draws on labile pools it was designed to extract and correlates well with plant micronutrient concentrations when the soil metal levels are neither too high nor too low.
It was developed by Lindsay W. L. and Norvell, W. A. in 1978.