Response of Young ‘Topred Delicious’ Apple Trees to Orchard Floor Management and Fertilization

Growth of ‘Topred Delicious’ ( Malus domestica Borkh)/Malling Merton (MM) 111 apple trees during the first 5 years in the orchard was significantly affected by the orchard floor management system. Trees grown in a mowed sod were smaller and had a significantly lower yield efficiency (kg/cm 2 ) than those grown under cultivation or a herbicide strip system. N source or rate did not influence growth or average yield/tree; fruit size and bitter pit development were significantly greater where a complete fertilizer (10N-4P-8K) was applied. N increased tree growth under sod but not under a cultivated or herbicide strip managment system. Growth response in the first year was increased when larger-sized trees were planted under a weed-free management system and trees were headed to 76 cm.