Phosphorus Deficiency and Flowering in Subterranean Clover (T. subterraneum L.)

Observations on three strains of subterranean clover indicated that phosphorus (P) deficiency, unless acute, had no effect on time of flower initiation. The node of first flower (NF) was, however, lower in P deficient than in healthy plants. Where the deficiency was acute, the time of flower initiation was delayed. Time of commencement of flowering was always delayed by P deficiency; with acute deficiency many plants died before flowering.