Soil exhaustion and rootstock effect on the growth of apple planting ...

Table 2. Rootstock <strong>and</strong> planting site <strong>effect</strong> on ‘Sampion’ apple tree height <strong>and</strong> trunk
diameter in the nursery.
514
Tree height, cm Tree trunk diameter, mm
Rootstock New Replanted Height New Replanted Diameter
field field decrement, field field decrement,
Factor A Factor B
% Factor B
%
Seedling 113.4 80.0 29.4 10.3 7.9 23.2
B.118 117.9 82.4 30.1 11.8 8.6 27.1
MM.106 101.6 67.0 34.1 9.3 7.4 20.5
M.26 99.0 66.0 33.3 9.1 6.2 32.4
P 60 94.1 57.5 38.9 8.8 6.3 29.0
B.396 92.7 74.1 20.0 8.5 7.0 18.5
P 2 91.5 79.5 13.1 8.2 7.5 9.0
M.9 98.2 70.0 28.7 9.4 7.8 16.8
P 22 94.9 68.8 27.5 9.7 6.8 29.4
P 59 99.7 61.3 38.5 9.6 6.7 30.0
LSD05AB 5.67 0.56
Average 100.3 70.7 29.4 9.5 7.3 23.6
LSD05B 1.3 0.13
Apple trees on seedling <strong>rootstock</strong>s <strong>and</strong> B.118 had significantly bigger trunk
diameter in the new field. In the replanted field significant differences remained only
when compared with B.118 <strong>rootstock</strong>. Significant differences were not established
among seedling <strong>rootstock</strong>, M.9, P 2 <strong>and</strong> MM.106 <strong>rootstock</strong>s. Trees on B.396 <strong>and</strong> P 2
<strong>rootstock</strong>s had the smallest trunk diameter in the new field, while in replanted
conditions their diameter was significantly thicker than on M.26 <strong>and</strong> P 60 <strong>rootstock</strong>s.
In some countries more vigorous <strong>rootstock</strong>s are suggested for use when replanting
in old apple l<strong>and</strong>, although it has been shown that vigorous <strong>rootstock</strong>s are as sensitive
to replant as dwarfing ones (Waechter-Kristensen, 1991). Some data reported that
dwarfing <strong>rootstock</strong>s CG.5935 (G.935) <strong>and</strong> CG.4202 (G.202) showed some tolerance of
replant disease (Robinson et al., 2004; Robinson et al., 2006). Our trial confirmed that
<strong>rootstock</strong> response to replanting did not depend on their growth vigour, therefore
specific <strong>rootstock</strong> behaviour should be taken into account when orchards are replanted.
Leaf area usually correlates with the intensity of photosynthesis <strong>and</strong> is an
important factor for maiden trees that need to use sun radiation <strong>effect</strong>ively. The tallest
<strong>and</strong> thickest trees on B.118 <strong>rootstock</strong> had the biggest average leaf area <strong>and</strong> dry leaf
weight in the fresh soil (Table 3). The lowest <strong>and</strong> thinner trees on P 2 had smaller leaf
area <strong>and</strong> dry leaf weight.
On average, leaf area <strong>and</strong> leaf dry weight decreased in replanted soil by 27.8 <strong>and</strong>
32.8% respectively. Our earlier performed investigations with cv. ’Auksis’ resulted in
smaller reduction of average leaf area <strong>and</strong> dry leaf weight (Kviklys et al., 2007). Such
differences could be attributed to specific <strong>rootstock</strong> cultivar combinations. The average
leaf area of cv. ‘Sampion’ on B.118 <strong>rootstock</strong> decreased in replanted soil more than
46%. Trees on M.26 <strong>and</strong> P 59 were also more sensitive among tested <strong>rootstock</strong>s. Their
absolutely dry leaf weight decreased around 40%. The lowest decrement of average
leaf area was recorded for trees on MM.106, seedling, P 60 <strong>and</strong> B.396 <strong>rootstock</strong>s,
while the lowest decrement of dry leaf weight was found on seedling <strong>and</strong> P 60
<strong>rootstock</strong>s.