The effect of pruning on the health of trees
The positive effect of pruning on the health of trees is often emphasized. Sick or dead shoots are removed during pruning, thus limiting the further spread of diseases. Removal of infected shoots plays an important role in combating apple mildew and brown rot in stone trees. In orchards composed of vigorous trees, pruning is necessary to enable the effective spraying of pesticides on the trees. Sprayers operating in the orchard have a limited range. The stream of liquid from the "Ślęza" sprayer manufactured in Poland does not reach higher than up to 4 m. The sprayed liquid cannot reach the central parts of the crowns if they are overly densified. By cutting, we regulate the size of trees and the density of branches, creating conditions for effective spraying.
On the other hand, pruning contributes to the development of bark and wood diseases in the orchard. Any tree injuries caused by pruning are at risk of being infected by pathogens. The greatest danger is from late fall to spring, so in the period, when we most often cut. At this time, fruit trees show a high sensitivity to infestation by fungi that cause bark gangrene, tree cancer and leaf silvery. Stone trees are most at risk: cherries, cherries, plum trees, peaches and apricots.
By proper conduct, you can limit the development of diseases associated with cutting trees. One important procedure is to lubricate all major wounds immediately after cutting. Suitable emulsions such as Funaben are used for lubrication 3 or Santar SM. Instead of emulsion, you can use white emulsion or oil paint with an additive 2% benzimidazole fungicides (Topsin M) and copper (copper 50). Due to this, that all small wounds cannot be smeared, after cutting each orchard plot, spraying with preparations such as: Funaben 50, Topsin M or Benlate in concentration 0,1%.
Stone trees that are more susceptible to infection should be cut mainly in sunny and dry weather. Cutting cherries is best done after the fruit is harvested, in late July and early August. The susceptibility of trees to infection is then the lowest.