INFLUENCE OF ONCE-IN-ALL OR GRADUAL REDUCTION AND BRANCH TYING DOWN OF OVERLAPPING CANOPIES ON THE GROWTH AND FRUITING OF OVERCROWDED APPLE TREES

Y.-K. Kim, H.-H. Han, C.-H. Lee
The average production of Korean apple trees per ha in 2001 was 15.3 tons which is only about 30% of the productivity of apples grown in the South Tyrol in Italy. One of the main reasons of the low productivity is considered to be the overcrowded canopies of Korean adult apple trees, caused by continuous heading cuts of the leading shoots on scaffold branches and heavy shortening cuts of branches. The necessity of renovating the overcrowded apple trees into non-overcrowded trees to be able to produce as many apples with good colour as the trees in Europe led to the establishment of trials aimed at canopy reduction plus branch tip tying down and removal of water sprouts on the adaxial parts of fruiting branches. The trees received once and for all treatment or gradual shoot reduction and branch tying down of overlapping canopies and these treatments were compared with no shortening or no shortening plus branch tying down. Reduced canopy width resulting in shorter or no overlapping canopies was achieved from the 1st year of treatment in 2000 through to the 3rd year in 2002. This opening up of alleyways for sunlight penetration into the overcrowded canopies by shortening cuts of overlapped canopies between the north-south tree rows brought about a reduction of the numbers of fruits produced per tree during the 1st and 2nd years but in the 3rd year the canopy shortened trees recovered their productivity to more or less the productivity of non-treated closed canopies. Fruit size generally remained the same between the shortening and non-shortening treatments except for a slight reduction in the non-shortened in the 2nd year. However, the percentages of 1st harvested apples observed in the 3rd year of experiment were larger in the canopy-opened trees than in the closed trees.
Kim, Y.-K., Han, H.-H. and Lee, C.-H. (2004). INFLUENCE OF ONCE-IN-ALL OR GRADUAL REDUCTION AND BRANCH TYING DOWN OF OVERLAPPING CANOPIES ON THE GROWTH AND FRUITING OF OVERCROWDED APPLE TREES. Acta Hortic. 636, 89-94
DOI: 10.17660/ActaHortic.2004.636.10
https://doi.org/10.17660/ActaHortic.2004.636.10
Malus domestica (Borkhausen), training, shortening cut, ¿Fuji¿ cultivar, fruit colour
English

Acta Horticulturae