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Investigations were conducted in the years 2006–2008 in Przybroda near Poznań on nectarine cv. ‘Fantasia’ trees with vase-trained crowns, planted in spring 2004 on peach cv. ‘Mandżurska’ rootstocks at a 4.0 × 2.5 m spacing (1000 trees ha⁻¹), strongly damaged by frost during the winter of 2005/2006. In the experiment 2 types of mulch were used in tree rows: fibre sheets and mown grass. In spring 2006 tree tops were headed back by 35–40 cm. In autumn 2006 pruned trees were by 0.4 m lower than unpruned trees, but trees mulched with fibre sheets were taller and had bigger crown projection areas than trees mulched with mown grass. In the 2nd year after heading-back the increment of trunk cross-sectional area was bigger in trees in combinations mulched with mown grass in comparison to fibre sheets mulching, as well as unpruned trees in comparison to pruned trees. Pruning of trees resulted also in the fruit-bearing zone in shooting of longer long shoots with a diameter of ≥0.5 cm, but only in the first year after pruning. In the third year after pruning the highest yield was produced by unpruned trees mulched with mown grass, while unpruned trees mulched with fibre sheets gave the poorest yields.
Studies were carried out in the years 2006–2008 in Przybroda near Poznań. Objects of studies consisted of 8-year old peach trees ‘Harbinger’ cultivar grown on three rootstocks: Manchurian Peach, Sand Cherry and Rakoniewicka Seedling. Tree crowns had a vase form and they were strongly damaged by frost during the winter 2005/2006. In spring 2006, intensive tree pruning was carried out. The objective of the studies was the estimation of the effect of a radical pruning of frostbitten trees on their regeneration and yielding, as well as to estimate the role of rootstocks in this process. Studies have shown that the tree pruning evoked a very strong compensation growth, the reaction of trees was the stronger, the more intensive was the tree pruning. As a result of the pruning, after 3 years, the lowered tree height (on the average by 40–50 cm) was maintained in relation to the control trees. After pruning, in the tree crown, longer productive long-shoots with diameters > 0.5 cm, developed as compared with the control. However, the radical pruning of trees caused in the third year after pruning a decrease in tree yielding from 30 to 40%, in comparison with the not pruned trees.
The aim of the studies was to assess the amount of wood to be gained during the pruning of apple orchards. The trials were carried out on the following cultivars of apple: 'Jonagold', 'Elstar', 'Idared', 'Jonica', and 'Rubinstar'. The chosen orchards in which the estimations took place had different interrow widths, tree distances and tree ages. The widths of interrows were from 3.5 m to 4.4 m. The distances between trees were from 1.5 m to 2.5 m. The ages of the trees were from 4 to 17 years. Pruned branches were manually collected from interrows along 20 grown trees. The mass of branches cut from a single tree, and the total mass of wood gathered on 1 hectare of orchard were calculated. The obtained results showed significant variability from 21% to 77%, between replications. This variability depended on cultivar and tree age. According to expectations, the highest amount of cut wood was achieved from the oldest, 17-year-old trees of the 'Elstar' cultivar. The mass of the branches cut from one 'Elstar' tree was from 1.92 kg to 2.43 kg, which means 3.7-4.6 tons of wood from 1 ha of the orchard. Of the 4-6-year-old trees of three cultivars: 'Rubinstar', 'Jonica' and 'Jonagold', grafted on M.26 rootstock,, less wood was achieved from 'Jonica' tree - 1.59 kg, on average. The highest wood mass gave 'Rubinstar' - 2.27 kg per tree, on average. Significant differences were observed in different years of the stud­ies when young trees became older. The most wood came from 'Rubinstar' - 960, 1700 and 2050 kg per hectare, in the 4th, 5th and 6th year of the study, respectively. In the same years 'Jonica' gave 780, 630 and 1450 kg/ha, respectively. In middle-aged orchards with 'Jonagold' and 'Idared', significantly more wood was obtained after cutting 'Jonagold' trees: 2100, 2000 and 2550 kg/ha, than after cutting 'Idared' trees: 780, 1440 and 1350 kg/ha in the 8th, 9th and 10th year of cultivation, respectively.
The research was carried out in 2006 within the area of forest nursery in Okalewo, the Forest Inspectorate Skrwilno (Central Poland, at 53º02´N, 19º23´E). The aim of the study was to determine the effects of root pruning in one-year Scots pine seedlings (Pinus sylvestris L.) on their growth after transplanting. The vertical roots of one-year Scots pine seedlings were pruned to the length of 5, 10, 15 i 20 cm and measured. The scope of measurements included: stem length and thickness, total root length, root length within thickness classes, surface root area, root volume as well as the number of root tips and ramifications. The measurements of root systems were performed with the use of a scanner and WinRhizo software. The seedlings were transplanted and were growing in the nursery all through the vegetation season 2006. In October of this year the seedlings were lifted from the ground and measured again at the same scope. Reiterated measurements allowed evaluation of increment characteristics after transplanting. The results indicated negative impacts of intensive root pruning before transplantation on seedling survival rates. Severe pruning of seedling vertical roots had negative effects on increment gained by both above- and underground seedling parts. Pruning roots to 5 cm of length significantly decreased pine seedling survival rate of. On the other hand, 20 cm long roots have no significant effects on seedling survival and increment but they can cause difficulties in seedling nursery cultivation.
In the years 2006–2008 in Przybroda near Poznań the objects of studies were peach trees ‘Harbinger’ on rootstocks Manchurian Peach, Sand Cherry and Rakoniewicka Seedling, formed as a spindle, severely damaged by frost in 2005/2006 winter. In May 2006, an intensive tree pruning was carried out. The objective of studies included the estimation of the pruning effect and rootstocks of frostbitten trees on the process of their regeneration and yielding. Pruning caused a decrease of tree height and crown width in relation to control. Trunks of the strongly pruned trees became thicker, as compared with control trees. In the third year after regenerative pruning, the trees decreased their yield by about 30% in relation to control. The best yielding trees were on rootstock Rakoniewicka Seedling, but the weakest on Sand Cherry.
The study assessed pruning efficiency of Scots pine (Pinus sylvestris L.) using different types of specialist pruning saws. Elements used in the study included the diameter and number of removed knots, pruning time per tree and passage time from one tree to another.
In this experiment, early ripening plum trees were pruned at two different times. The experiment was conducted at the Fruit Experimental Station in Samotwór near Wroc ław in 2001-2004. Objects of the study were 8 year-old plum trees of 'Herman', 'Cacanska Rana', 'Sanctus Hubertus' and 'Cacanska Lepotica' cultivars budded on 'Myrobalan' seedlings (Prunus divaricata). The experiment was established in a randomised block design in three replications with 6 trees per plot. In 2001-2003, time of tree pruning was differentiated. Half of the trees were pruned only at the end of August (summer pruning after harvest of fruit). The other pruning took place at the end of March (dormant pruning before blooming time). Time of pruning had no influence on vegetative growth and chemical composi­tion of leaves. No matter what the time of pruning, the total sugars, reducing sugars, potassium, calcium, magnesium and phosphorus contents in leaves were similar. Sugars, calcium and phosphorus contents were significantly influenced by the year. Foliar nutrient content differed according to the plum cultivar. 'Sanctus Hubertus' showed markedly lower leaf K and Mg contents, whereas 'Cacanska Lepotica' had a higher P content. Pruning time had an influence on the crop efficiency index. Dor­mant-pruned trees were significantly more productive.
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