Cutting fruiting cherries.
After the trees enter the fruiting period, x-rays combined with periodical rejuvenation of crowns must be used in commercial orchards, or a renewing cut.
Irradiation is an appropriate pruning method for relatively young trees. It consists in removing excess twigs and limbs, in order to loosen the crown and allow light to enter it (Lynx.).
Lynx. Overexposure of fruiting cherry.
X-rays are started after the crown formation is completed and we do it every year in the first years of fruiting trees. After that, x-ray alone is not enough.
Usually, after several years of intensive growth and fruiting of cherries, growth stops. Side shoots are short and covered with flower buds along their entire length. Only at the top of the shoots are leaf buds. After fruiting, such shoots do not develop any branches or leaves and remain bare. The stripping of the shoots is the most characteristic of the Lutówka variety.
The fruiting zone moves to the periphery of the crown, while the center of the crown remains unproductive. To prevent this from happening, older cherry trees should be rejuvenated every few years. Rejuvenation is based on a strong shortening of the limbs, making, that the buds located in the depths of the crown produce new annual shoots (Lynx.).
Lynx. The limb of the Lutówka variety, after shortening, produced young, valuable gains.
Cherries require rejuvenation every 3-5 years. In the remaining years, we use x-rays.
Another method of pruning older trees is called renewing pruning. Renewal pruning consists in maintaining a constant rotation of fruit-bearing shoots in the crown, one and two years old. With the same method of pruning, the tree has limbs, from which only annual and biennial shoots grow. Two-year-old shoots are cut after fruiting, but not at the limb itself, and leaving a suppository a few centimeters long. Such a suppository makes it easier to break out new shoots. The renewing pruning is widely used in the cultivation of line-shaped apple trees. Due to the fruiting nature of apple trees, a 3-year rotation of shoots is most often used. Renewal pruning with a two-year rotation of shoots should give good results when growing cherries in the form of a free row. It is especially suitable for the Nefris and North Star varieties. The renewing pruning will probably not be applicable to the cultivation of the Lutówka variety, because it does not produce a sufficient number of annual shoots.
Fruitful cherries need to be pruned in the summer. The best time to cut cherries is July and August after the fruit harvest. Cutting wounds should be lubricated with Santarem or emulsion paint with an additive 2% Topsinu i 2% Miedzianu.