ISHS Acta Horticulturae 444: III International Symposium on Kiwifruit
EFFECT OF REDUCING BETWEEN-ROW SPACING IN KIWIFRUIT ORCHARDS |
| Authors: | G. Costa, R. Testolin |
| Keywords: | Actinidia deliciosa, training system, plant spacing, plant density, pruning, bud load |
| Abstract:
We report a study on row spacing accomplished by narrowing the distance between rows from 4.5 (the control) to 4.0 and 3.5 m. Training and pruning were adapted accordingly to have, in all cases, clear alleyways of fixed width. The experimental orchard was established in 1988. The male to female ratio was maintained at 1 to 7. Vines were pruned to reach a load of either 27 buds/m2 of planar canopy projection area or 15 buds/m2 of orchard ground surface. Where a constant bud load per unit of planar canopy projection area was adopted (27 buds/m2 in our case), the cumulated yield (1991–1994) decreased from 64.8 to 46.6 t/her upon decreasing spacing between rows because of the proportional reduction of soil exploitation. Where a constant bud load per unit of ground area was adopted (15 buds/m2 in our case), we observed a similar reduction in cumulated yield from 65.9 to 49.9 t/her in the closer spacing, which was due in this case mainly to a reduction in bud fertility as a consequence of the increased canopy density. The mean fruit weight ranged from 94 to 96 g without any appreciable difference between treatments. Reducing the row spacing achieves the opposite result that reduction of in-row spacing does, because the number of alleyways, whose width must be kept constant, increases and, as a consequence, the ground surface covered by the cropping canopy is reduced. This crop reduction, that is theoretically predictable, cannot be counterbalanced by any pruning strategy. | |
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