Comparison of the effects of high levels of DTPA and EDDHA on microelement uptake in bush beans

Abstract

Abstract Bush beans (Phascolus vulgaris L. var Improved Tendergreen) were grown for 21 days in noncalcareous Yolo loam soil with 0, 500, and 1000 ppm of DTPA (diethylene triamine pentaacetic acid) and also of EDDHA (ethylenediamine di(o‐hydroxyphenylacetic acid)) applied as the Na salts. The objective was to learn more of DTPA‐increased uptake of some heavy metals. The high levels of both agents tended to depress yields and result in leaf symptoms of excesses of metals. Both agents resulted in large increases of Fe in shoots. DTPA resulted in much larger increases in Zn, Cu, Mn, Co, Ni and Pb than did EDDHA. For Cu, Co, and Ni the proportional increases with DTPA were greater than that for Fe. Aluminum was increased more by EDDHA than by DTPA while Mo was increased almost equally by the two chelating agents. Chromium was increased slightly by each agent, but V was unaffected. Leaf/stem ratios were increased by DTPA for Co and Ni and to a lesser extent for Fe and Zn indicating some transport through the pl...