the effects of trunk scoring and pruning methods on fruit quality of ...

E. Gudarowska <strong>and</strong> A. SzewczukTearing <strong>of</strong>f shoots is a faster method <strong>of</strong> training <strong>of</strong> trees than <strong>pruning</strong>(Mika, 2002). However, tearing <strong>of</strong>f weak shoots could reduce induction <strong>of</strong>flower buds (Poniedziałek et al., 2000).MATERIAL AND METHODSThe experiment was carried out in 2001-2004 at <strong>the</strong> Experimental Stationin Samotwór near Wrocław. Trees <strong>of</strong> <strong>the</strong> cultivars ‘Elstar’ <strong>and</strong> ‘Jonagold’were planted in <strong>the</strong> spring <strong>of</strong> 1995 on M.26 <strong>and</strong> M.9 rootstock 3.5 x 1.2 mapart (2381 trees per ha) <strong>and</strong> trained as spindles. Eight years after planting,<strong>the</strong> <strong>trunk</strong>s were scored <strong>and</strong> <strong>the</strong> branches in <strong>the</strong> centre <strong>of</strong> <strong>the</strong> canopies werebroken. The control trees were pruned with shears during blossoming. Trunkswere scored during blossoming with a h<strong>and</strong> saw at two places: 15 cm <strong>and</strong> 65cm above <strong>the</strong> budding place. Score were made on opposite sides <strong>of</strong> <strong>the</strong> <strong>trunk</strong>to a depth <strong>of</strong> one third <strong>of</strong> <strong>the</strong> circumference. Two-year-old branches werebroken at <strong>the</strong> end <strong>of</strong> May <strong>and</strong> <strong>the</strong> beginning <strong>of</strong> June. Stronger branches werepruned with shears, <strong>and</strong> shoots in <strong>the</strong> upper part <strong>of</strong> a canopy were torn <strong>of</strong>f.The last treatment included both <strong>trunk</strong> <strong>scoring</strong> <strong>and</strong> branch breaking.The experiment was carried out in a r<strong>and</strong>omized block design with fourreplications <strong>of</strong> four trees each. The yield per tree, mean weight <strong>of</strong> apples, <strong>the</strong>size <strong>of</strong> fruit in every class <strong>of</strong> diameter <strong>and</strong> <strong>the</strong> fruit skin covered with blushwere assessed.Data were statistically elaborated by analysis <strong>of</strong> variance, followed byDuncan’s multiple-range t-test at P ≤0.05.RESULTS AND DISCUSSIONThe <strong>methods</strong> <strong>of</strong> training <strong>of</strong> trees used in <strong>the</strong> experiment can have aninfluence on <strong>the</strong> yield <strong>and</strong> its quality. However, this influence depends on <strong>the</strong>cultivar <strong>and</strong> rootstock.T a b l e 1 . Yield <strong>of</strong> ‘Elstar’, depending on <strong>of</strong> <strong>trunk</strong> <strong>scoring</strong> <strong>and</strong> breaking <strong>of</strong> branchesTreatmentYield [kg tree -1 ]Total yield2001 2002 2003 2004 2001-2004M.26Control 8.7 a* 11.1 abc 12.5 bc 7.0 a 39.3 abcTrunk <strong>scoring</strong> 5.5 a 21.5 bc 7.6 abc 17.9 bc 52.5 cTrunk <strong>scoring</strong> +branch breaking6.0 a 3.9 ab 14.6 bc 1.7 a 26.2 aBranch breaking 3.5 a 8.3 ab 14.8 c 1.9 a 28.5 abM.9Control 7.7 a 20.0 bc 5.1 ab 13.7 abc 46.5 cTrunk <strong>scoring</strong> 5.1 a 25.3 c 2.5 a 20.0 c 52.9 cTrunk <strong>scoring</strong> +branch breaking4.9 a 15.7 abc 10.7 abc 12.4 a 43.7 bcBranch breaking 3.0 a 12.9 abc 10.7 abc 9.2 ab c 35.8 abc*Means followed by <strong>the</strong> same letter do not differ significantly at P=0.05 according to Duncan’s t-test178J. Fruit Ornam. Plant Res. vol. 14 (Suppl. 2), 2006: 177-182