A plant disorder in lentils, known as “Marea Negra” or “Roña” in Chile, was studied. First the isolation of patogen microorganisms from the diseased tissue was tried without positive results; then, the sterilization of soils with the problem was also tried, but the disorder persisted; therefore microorganisms were discarded. Further studies showed that “Marea Negra” was not seed born, and that it was apparently produced by sorne element (s) of the soil; also it was always related with high foliar contents of manganese and ron. This could be the first reference of such a problem in the world. |