DETERMINATION OF CRITICAL LEVELS OF MINERAL NUTRIENTS IN PEAR LEAVES

Field experiments and/or analysis of leaves from orchards deficient in N, B, S, Mg, P, and K, as well as research elsewhere, were used to establish deficient, below normal, normal, above normal and excess levels for leaf samples taken in August.
Mineral levels found in deficient and normal mid terminal leaves are reported and symptoms of deficient are described.
Deficiency is considered to exist at leaf levels below the following; K 0.4%, P 0.1%, Mg 0.18%, S 0.1%, B 25 ppm.

III International Symposium on Pear Growing

R.L. Stebbins

https://doi.org/10.17660/ActaHortic.1982.124.17