The phosphorus budget of a field‐grown strawberry (Fragaria x ananassa cv. Hapil) crop: evidence for a mycorrhizal contribution

Summary The phosphorus content of a field‐grown strawberry crop was monitored over one growing season and the allocation of P to different plant parts determined. In the early part of the season, leaves were the major sink for P and this was partly supplied by redistribution from rhizomes. Once flowers were initiated, these became the major sink and their P requirement was satisfied by new uptake. The calculated rates of P inflow to the roots in this phase of growth were so large that it was necessary to postulate not only that P uptake was assisted by mycorrhizas, but that the whole root system, including the old, brown roots, was active. The implications of this conclusion for concepts of vesicular‐arbuscular mycorrhizal function under field conditions are discussed.