ISHS Acta Horticulturae 451: VI International Symposium on Integrated Canopy, Rootstock, Environmental Physiology in Orchard Systems
EARLY RESULTS WITH INTENSIVE SYSTEMS OF APPLES ON VIRUS-FREE M.9 ROOTSTOCK IN NEW ZEALAND |
| Authors: | John W. Palmer, H. M. Adams |
| Keywords: | yield, fruit quality, light interception |
| Abstract:
In common with growers in many other parts of the world, some New Zealand growers are seeking to improve precocity and to reduce production costs by planting apple trees more intensively on dwarfing rootstocks. Unfortunately all commonly available dwarfing rootstocks are susceptible to woolly apple aphid. However, this pest may not be too serious in the cooler regions of New Zealand. Virus-free M.9 has only recently become widely available in New Zealand and a number of within-row spacing trials of single row slender spindles have been planted over the last few years in the northern part of the South Island. Early yield results are presented in this paper. Yields per hectare from well-feathered trees in the second leaf ranged from 26 t/ha for ‘Fuji’ at 2198 trees/ha to 7 t/ha from ‘Royal Gala’ at 1143 trees/ha. In the third leaf, yields varied from 44 t/ha to 18 t/ha for the same treatments. Trials have shown clear advantages of using well-feathered trees compared to unfeathered whips, with at least a twofold increase in yield per tree in year 2 and 3. Trials on grower properties with unfeathered trees of ‘Royal Gala’ produced 7 t/ha in the second leaf and 30 t/ha in the third, with a tree density of 2000 trees/ha. In a trial planted on very variable soil conditions, yield per hectare in the third year was linearly related to light interception and to TCA per hectare. | |
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