EFFECTS OF SOIL-PH AND NUTRIENTS ON GROWTH OF APPLE SEEDLINGS GROWN IN APPLE REPLANT DISEASE SOILS OF BRITISH-COLUMBIA

Relationships between McIntosh apple seedling growth and pH along with soil nutrients in 568 apple replant disease (ARD) soils were examined by regression analysis. Sixty percent of the ARD soils in the Okanagan-Similkameen valleys had pH values between 6-7.5. All three major nutrient elements (N, P and K) had positive relationships with plant height when the soil pH was greater-than-or-equal-to 8. When the soil pH was lower than 5.4, only P had positive relationships with plant height. When the soils were treated with monoammonium phosphate or ammonium nitrate, pH had significant negative relationships with the plant height.