Abstract
Four cases of lawsuits involving use of chelating agents in plant nutrition are discussed. Three of them involved use of iron. One concerned addition of FeDTPA to nursery trees in containers. One case involved foliar application of FeHEDTA to potatoes in July by airplane. Another case not involving iron chelate was with ZnEDTA and MnEDTA with Fe as FeSO/sub 4/ later as a foliar spray. The Zn and MnEDTA were applied as a band 8 inches (20 cm) on both sides of nursery tree rows just as the buds that had been placed in the fall began growing in the spring. In the fourth case, many tomato transplants died when the transplanting was done with about 120 ml per plant of transplant solution containing besides N, P and K, about 19 mg Zn as ZnEDTA, 14 mg Mn as MnEDTA and 7 mg Fe as FeHEDTA. Cases such as these will probably discourage use of chelating agents in plant nutrition even if the chelating agents were not the damaging agent. Not enough developmental work was done on the potential toxicities from metal chelates. This trend to lawsuits makes it even more important to solve iron chlorosis problems via plant breeding.