Abstract: | The visual symptoms caused by deficiency of calcium, magnesium, potassium, and nitrogen in seedligs of Pinus radiata Don., grown in sand, ere described. In the treatment in which phosphorus was omitted from the nutrient solution, the plants grew very slowly at first but later their growth rate was rapid. Since the sand in which the plants were growing contained some apatite, it is believed that the mycorrjhizal fungus was able to mobilize phosphorus from the apatite and make it available to the pines. |