Over de beteekenis van koper voor de groei van planten en micro-organismen : in het bijzonder een onderzoek naar de oorzaak der ontginningsziekte
1938
Mulder, E.G.
Cereal plants growing on newly reclaimed peaty and heath soils often showed serious symptoms of 'reclamation disease' which were cured by adding Cu salts. To elucidate the function of Cu in this plant disease, several plant species were grown in purified water-culture and sand media practically free from Cu. The symptoms of Cu deficiencies obtained were identical with the symptoms of plants growing in 'diseased' soil. The considerably larger amounts of Cu needed by plants growing in 'diseased' soil proved to be due to the fixation of Cu by the black organic matter of the soils.Further evidence that a low content of available Cu was the cause of reclamation disease was provided by a microbiological method. In this test the colour of the spores of Aspergillus niger grown in a copper-deficient medium supplied with small amounts of soil was a measure of Cu supply to the fungus.In addition to fixation by certain types of organic matter, bacteria producing hydrogen sulphide may precipitate soluble Cu so that it becomes, at least temporarily, unavailable.With humid air, symptoms of Cu deficiencies were less severe. Copper-deficient wheat plants were more susceptible to fungus diseases. Application of Cu salts may sometimes cause manganese deficiency. Cu was, found to be required by some micro-organisms.
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