IDENTIFICATION OF K DEFICIENCY IN BRITISH COLUMBIA APPLE ORCHARDS

K deficiency was identified for the first time in British Columbia orchard soils. Greenhouse-grown apple seedlings responded to K in soils low in available K. MacSpur McIntosh (Malus domestica Borkh.) had increased leaf K (above deficiency) and improved initial fruiting after surface applications of KCl in an orchard with low soil K. Key words: Potassium deficiency, apple, leaf and soil potassium