Abstract
Effects of dwarf rootstocks on tree growth, yield and fruit qualities of young ‘Amakusa’ and ‘Amaka’ trees were compared with common Trifoliate orange and ‘Flying Dragon’ trifoliate orange rootstocks in order to improve fruit qualities and to maintain a small canopy for easy cultural operation.
For both cultivars, the volume of the tree crown four years after planting was significantly smaller on ‘Flying Dragon’ (FD) rootstock than on the common trifoliate orange (P) rootstock. Overgrowth of rootstock was observed in the cultivars on both rootstocks 6 years after planting. The degree of rootstock overgrowth was greater for trees on FD than for those on P rootstock. Both soluble solid and acid contents of the fruit juice were higher on FD rootstock than on P rootstock for both cultivars. Although yield per tree was greater on trees with P rootstock, yield per unit canopy volume (kg/m3) was greater on trees with FD rootstock. FD rootstock was considered a suitable rootstock for maintaining compact canopies and produced higher quality fruit for both ‘Amakusa’ and ‘Amaka’.
