The Effect of Orchard Floor Management and Nitrogen Fertilization on Nutrient Uptake and Fruit Quality of ‘Golden Delicious’ Apple Trees

Mature ‘Golden Delicious’ apple trees (Malus domestica Borkh.) were subjected for 3 years to factorial combinations of 3 rates of N fertilization applied in April and 3 degrees of orchard floor management. Tree N nutrition was affected more by vegetation management than by rate of N fertilizer applied. Significant reduction in leaf N and trunk diameter, and superior fruit skin color and firmness at commercial harvest occurred consistently when the orchard floor was sod. Increased leaf N and reduced fruit skin color and firmness at harvest were measured at the highest N (180 kg N ha-1) in only 1 year while tree growth was not increased by this rate of N. Increased fruit Ca associated with smaller fruit and increased leaf Mg and leaf K were measured under sod in 2 of 3 years. Leaf Mn was affected only by rate of N fertilization and was consistently high at 180 kg N ha-1.