Root Restriction, an Alternative to Rootstocks, for Control of Flowering, Fruiting, Tree Growth, Yield Efficiency, and Fruit Quality of Apple

Apple (Malus Xdomestica Borkh.) trees planted in root-restriction bags provided an alternative to dwarfing rootstocks for control of tree vigor. Root restriction suppressed tree growth, reduced the need for pruning, and increased tree flowering, yield efficiency, and fruit color, firmness and soluble solids concentration. Root bags, with hole sizes of less than 2 mm in diameter restricted tree growth and root development more than desirable. Galvanized wire mesh was toxic to roots, limited root and tree growth, and caused significant leaf yellowing. Root bag materials did not inhibit root bag penetration or damage to the apples by voles (Microtus spp.). Only galvanized wire mesh (hardware cloth) and/or screen wire excluded voles from apples.