The question may arise spontaneously for the amateur fruit grower: "What need is there to prune the plants? In nature they know for themselves how to regulate themselves". Well, even if this consideration is correct, we must never forget that man raises fruit plants with purposes very different from those that nature sets itself.
In nature, fruiting is simply aimed at the perpetuation of the species, without yield objectives. To us instead it is important that the plants produce a good quantity of fruit with consistency and quality, as explained in the guide to the orchard, and precisely in this we are helped by pruning interventions.
That said, we should still prefer sustainable pruning techniques, which comply within the limits of the natural expressions of development of the plant. In fact, organic fruit growing aims to respect the natural tendencies of bearing and growth of plants by directing them correctly.
In this article we will find out what pruning is and outline some useful general guidelines for this work. On Orto Da Coltivare you will also find guides for pruning each fruit plant, with specific indications for each tree.
What is pruning
Pruning is the set of operations aimed at guiding the plant in its development, limiting its size, regulating the load of the fruit and favoring the interception of sunlight by the foliage. These are mainly cutting operations, but they also include bud removal, thinning and bending of branches.
The reasons for pruning are more than one:
- Stimulate the productivity of the plant.
- Adjust production so that it is constant from year to year.
- Improve fruit size and quality.
- Keep the plant healthy.
- Regulate the hair.
- Set and maintain a shape and size of the plant (important from an aesthetic point of view, but also for ease of management).
The different types of pruning
Basically when we refer to pruning we must distinguish between the following types:
- Breeding pruning, which is carried out in the first years of planting, and serves to give the plant the desired shape. For each species there are certain forms of farming considered suitable for production purposes and which often facilitate the operations of harvesting from the ground making stairs unnecessary. With farming pruning, the formation of a harmonious skeleton is favored and the plant's entry into production is encouraged;
- Production pruning, is the one that is performed regularly on the plant in the years following the actual entry into production. The main purpose of this type of pruning is to balance the vegetative and reproductive development, and avoid problems such as alternation of production (years of fruit load alternating with years of discharge);
- Reform pruning, to be done when necessary, for example in cases where you have to change the shape of a plant, or give it back after years of "wild" growth in which there has been no pruning.
Know the plant
Before pruning a fruit plant it is essential to have a basic understanding of its nature and physiology. In the articles that will concern the pruning of each individual species we will go into details, but in summary we can now remember that:
- The However depending on the variety it tends to produce on short peduncles called lamburde, and on the brindilli, branches of 15-30 cm at most with a terminal flower bud.
- The Apple tree it bears fruit on 1-year-old brindilli, 2-year-old lamburde and on mixed branches composed of wood buds and a terminal flower bud (and which therefore must not be shortened, otherwise they do not produce).
- The stone fruit (peach, plum, apricot, cherry and almond) fruit mainly on brindilli, on mixed branches (which unlike those of pome fruit have many flowers and end with a wood bud and therefore can undergo shortening cuts), and on squat twigs called bunches of May, productive for many years.
- The FIG bears fruit on 1 year old shoots and branches, the olive tree on the shoots, citrus fruits on 2 year old branches and on shoots, actinidia on 1 year old branches, persimmon on 1 year old branches, vines on 1 year old branches, 1 year, walnut and stone on the shoots.
However, there are differences between individual species and between different varieties of a species.
The time to prune
There are two distinct times to prune during the year: winter and summer pruning.
Production winter pruning can be practiced from autumn until before flowering, or on deciduous plants at rest. Postponing it to just before flowering gives the advantage of recognizing the flower buds well, because they are more swollen than the wood ones and this allows you to decide the load of flowers to leave.
Summer or green pruning
Green pruning can occur at various times during the growing season, and depending on when it is performed, different results can be obtained. For example, late cuts in mid-August will give rise in the future to a contained and orderly growth of the plant, while anticipating them in July means witnessing a certain vegetative emission.
Technically we speak of removal of a branch or a branch when these are cut at the base, if they are badly positioned or in excess, or too vigorous. The important thing is to make the cut correctly. It must be remembered that a cut always creates a wound to the plant, which must react and be able to heal it. At the base of the branch there is an area of enlarged bark called collar, and is the seat of the defense and healing mechanisms of the plant, from which a callus is formed that will close the cut wound. For this to happen, the cut, therefore not being flush, must leave a small portion of wood. The shortening cuts of the branches are distinguished in trimming, if they occur a few centimeters from the apex; the shortening real if they are in the central part of the branch; is ramming if you cut close to the base leaving only a few gems. They are cuts that stimulate the vegetation to the detriment of production, and are useful for rejuvenating portions of the plant.
We talk about return cut to indicate the removal of the apex of a branch above a lateral branch, which in turn becomes the top. The term "return" refers to the rapprochement to the center of the periphery of the canopy. Even the shortening cuts must be performed with care, avoiding damage to the plant, destined to have consequences also in the following year. The cut is made on a gem, but not too close to it, and must be tilted in the same direction as it. The gem, which exerts a strong lymph call, allows a good healing of the cut.
The bending and inclinations of the branches are alternative interventions to cutting, and affect the circulation of the sap in the plant. Vigorous branches bent down generally tend to weaken. The branches can also be tilted or spread apart instead of bent in a curved way, and this generally increases their productive activity compared to the vegetative one.
The operations described above mainly concern winter pruning, while on the green there are other possibilities such as the removal of excess shoots or in an unsuitable position, topping of shoots and thinning of the fruits, useful for lightening the plant and avoiding the phenomenon of alternation of production. In fact, when a plant produces many fruits, there is little flower differentiation of the buds for the following year and therefore low future production. However, fruit thinning must be done with care and at the right time, neither before nor after, usually just before the stone hardening for stone fruit and at the fruit-nut stage for pome fruit.
The operations to always do
There are some general pruning operations that must be performed whenever needed. One of these is the elimination of suckers, or the branches at the base of the plant, which are usually generated by the rootstock; or even the elimination of suckers, or other vertically growing branches which, however, unlike the former, form on a branch. Both types of branches take nourishment from the plant and have no productive value.
Even dry or diseased branches must be regularly eliminated, and those too bundled together, must be thinned out to allow the plant to be ventilated and have the right solar irradiation. Overhanging branches or even branches inserted into the trunk at a too narrow angle must be cut because they risk falling apart and therefore causing a great injury to the plant.
To perform proper pruning you need to have the right equipment.
The shears they are used to cut branches up to 2 cm in diameter. It is very important that they are robust and of good quality because otherwise they break easily. With the shears you have to make clean cuts, without fraying the branch.
The lopper, to be used with two hands, it is a shears with handles about 80 cm long, useful for cutting branches with a diameter of 3-5 cm. The important thing is that it is robust and at the same time light.
The pruner it has a long fixed or telescopic shaft with a blade that can be operated by a spring or chain mechanism: it is useful for pruning trees up to 5 meters high, avoiding the ladder.
The hacksaw it is used to cut larger branches and should be able to allow quick and precise cuts.
Finally the chainsaw a motor could be used for cutting large branches, in the rare cases where topping or killing at the base of a dead plant are necessary. We remind you to use it only while wearing safety equipment (helmet, overalls, gloves, boots).
Plants actually have a natural tendency to regulate their branch charge. When a branch is in a very disadvantageous and particularly shaded position, usually at the bottom, the plant tends to exclude it by interrupting the supply of sap, until it dries up and falls naturally.
The management of pruning residues
After pruning an orchard, branches usually build up. These, as it seems obvious, can power stoves or fireplaces, which not everyone has. A valid alternative is to return them to the earth after a shredding process with a shredder and subsequent composting. For these shredded remains to decompose well, however, it is advisable to mix them with other more tender organic substances (ie containing less lignins). When the compost is ripe it can be distributed again in the orchard and in this way, even if it should not be the only source of replenishment, part of the organic substance consumed is returned to the earth.