|
|
|
| Authors: | F. Gyuro, M. Gondor-Pinter, K.A. Dib |
Abstract:
Detailed studies on trees of Jonathan, Golden Delicious and Starking Delicious on M.9, M.4 and seedling rootstocks and on their own roots, planted in 1968, were carried out over the years 1979–1981. The objective was to determine those parts of the tree canopy which were most productive, especially in terms of fruits of high quality, and to assess the effects of rootstock and variety on this.
Results were as follows:-
- Variety has less effect than rootstock on tree size.
Trees of the same variety were five or six times as large in terms of crown volume when grown on seedling rootstocks than when grown on M.9. Trees of Starking Delicious on their own roots were surprisingly small, being only half as large as those on M.4 or on seedling rootstocks.
- The outer zone at the top of the trees is the most productive.
On average this constituted 70–73% of the tree canopy volume while the inner zone, which usually lost its leaves, made up only 3.7–5.1% of the tree canopy volume.
- All of the fruits of the Jonathan and the Golden Delicious trees on M.9 were within 2 metres from the ground.
Averaged over varieties 35, 38 and 42% of the fruits on trees on M.4, their own roots and seedling rootstocks were in zones more than 2 metres from the ground.
- The fruits were largest on the Jonathan trees and were rather small on the Golden Delicious trees.
Own-root trees of this variety gave better-than-average fruit size with 37% of the fruits in the over-60 mm category, so may be advantageous.
Trees of this variety on M.9, M.4 and seedling rootstocks had 30, 15 and 3% of their fruits in the over-60 mm category.
- The number of fruits of more than 60 mm diameter was always greatest in the outer part of the top of the trees.
The best-coloured fruits were also found there: the higher the position in the tree the higher being the fruit colour.
|
Download Adobe Acrobat Reader (free software to read PDF files) |
  
|