Cutting young trees and shrubs - by reducing the number of fruit-bearing shoots and flower buds, it almost always reduces the fruit yield. Therefore, young trees are recommended to be pruned only when necessary and as little as possible. It is different with older trees. After trees enter the period of abundant fruiting, that is, 6-8 years after planting for the orchard, they produce a large number of fruit-bearing shoots, where they create much more flower buds than are necessary for a large fruit yield. If fruiting is not regulated by cutting, what happens in untreated trees, then too much fruit grows on the tree. There are a lot of them, but they cannot grow. The yield does not have adequate commercial value.
On older apple trees, 5-10% of flowers will bear fruit. So, with abundant flowering, it can be removed 1/3 flowers without causing a significant yield loss. Cutting old trees by shining the crowns does not reduce the yield or it does not, but insignificantly (table).
Table. The influence of pruning on the yield depending on the age of semi-dwarf apple trees (according to A. Mica, A. Jackiewicz. M. Potocka)
| Variety | Total fruit yield in kg per tree | |||
| young apple trees (3-7 lat) | older apple trees (8-11 lat) | |||
| cutting
weak |
cutting
strong |
cutting
weak |
cutting
strong |
|
| Mclntosh | 135 | 79 | 387 | 340 |
| Bankroft | 113 | 97 | 265 | 270 |
| Jonathan | 112 | 88 | 250 | 235 |
| Golden Delicious | 129 | 110 | 309 | 304 |
However, you have to take into account, that in modern orchards it is not only the crowns of trees that are overexposed, but at the same time it regulates their size. The trees are pruned from the top, so that they have a height within the limits of 2,5 into 3,0 m and is limited by cutting the crown growth to the sides, to fit on an area of several or several square meters. Under these conditions, the crowns of trees are much smaller than the crowns of freely growing trees, and proportionally to this, the fruit yield per tree is lower.. By limiting the size of trees by cutting, we limit the potential yields that an individual tree could produce. However, we accept this knowing, that it is not the yield of the tree that determines the income from the orchard, but the yield per hectare. The fruit from the top of a tall tree is often blown off by the wind. The number of small trees is much greater than that of large trees and they are easier to care for, in addition, the cost of harvesting fruit from low trees is much lower than from tall trees.
The above-mentioned relationships also apply to fruit shrubs. In commercial plantations, the size of the shrubs is limited by pruning, hence the yields from one bush are lower than under the conditions, when bushes grow unregulated.
It happens from time to time, that the orchard will plant the orchard excessively densely and try to keep it in this dense spacing by cutting the trees very intensively. If the pruning is very intense, it can inhibit the formation of flower buds even on older trees, flowering and fruiting. After each spring cut, the trees give numerous and long shoots, and the fruiting is weak. Instead of producing fruit, the orchard produces useless wood.
It is worth asking whether it is possible to increase the fruit yield by means of pruning, at least in sporadic cases? Well, some experiences produce just such a result. Let's take two plots of adult apple trees, one of which is uncut and has tall and dense trees. The second cut plot has low trees, loose crowns. It will not be possible to spray effectively on the first one, therefore the fruit yields may be lower than in the second quarter, properly cut. The positive effect of cutting on the apple yield in the described case is only apparent, resulting from the conditions of protection of the tree against diseases and pests.