Cobalt requirement of symbiotically grown alfalfa


Alfalfa was grown in purified culture solutions to which different amounts of radioactive Co were added. Treatment effects were evaluated by measuring the yield, N and Co content of the plant tops; and the weight, volume and leghemoglobin content of the root nodules. The Co requirement of symbiotic N fixation was met with 10 ppt of the element in the rooting medium; this amount gave plants containing 0.0005 ppm of Co in their whole tops and 0.0008 ppm of Co in their leaves. Leghemoglobin was found in measurable amounts only in nodules which were fixing N at the time of harvest. The level of added Co had no effect on the weight or volume of root nodules formed, nor were the Co levels supplied related to the leghemoglobin content of the nodules.

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Scientific Paper No. 2301, Washington Agricultural Experiment Station, Pullman. Project Number 1526. This investigation was supported in part by funds provided for biological and medical research by the state of Washington Initiative Measure No. 171.

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Wilson, D.O., Reisenauer, H.M. Cobalt requirement of symbiotically grown alfalfa. Plant Soil 19, 364–373 (1963).

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  • Nodule
  • Cobalt
  • Plant Physiology
  • Treatment Effect
  • Root Nodule