EFFECT OF SOME DWARFING METHODS ON TREE GROWTH, CROPPING AND FRUIT QUALITY OF ‘JONICA’ APPLE

Different methods of apple tree dwarfing were compared, including dwarfing rootstocks (‘M.9’ and ‘P60’), grafted rings of ‘Jonica’ scion bark (in normal and inverted position), microinterstocks of dwarfing rootstocks (‘M.9’, ‘P22’, ‘M.27’) and a growth retardant (paclobutrazol). A microinterstock is a ring of bark taken from a dwarfing rootstock and grafted on the tree’s trunk.
The biggest reduction in tree vigour was obtained with an inverted ‘Jonica’ scion bark ring and microinterstocks.
Although the inverted bark graft ring, the ‘P22’ microinterstock and the growth regulator treatments made trees flower more abundantly, yield was reduced for the inverted bark ring and all of the microinterstocks compared to the control.
All microinterstocks and the paclobutrazol treatment tended to increase soluble solids concentration (SSC) in the fruits.
These treatments also improved fruit firmness but had no negative effect on mean fruit weight.
Calcium content of the fruits was lowered by using microinterstocks, the only exception was the microinterstock ‘P22’.

VIII International Symposium on Canopy, Rootstocks and Environmental Physiology in Orchard Systems

M. Gastol, W. Poniedzialek

Malus × domestica, rootstock, bark grafting, flowering, fruit mineral content

https://doi.org/10.17660/ActaHortic.2007.732.29