Thinning or thinning fruit trees is the process of removing some fruits from trees while they are still small. Cutting a large part of the fruits that have just begun to grow can make the remaining ones develop relatively larger and more uniform, but in smaller quantities.
Studies show that reducing the amount of fruit on each plant not only improves the size, but greatly increases the sugar content of the fruit and even phytonutrients (chemicals that help protect plants against germs, fungi, insects, and other threats).
The thinning of fruit trees, although it may not seem like it, is a benefit for the plant. There are trees that produce too much fruit. If we allow everything to ripen, the fruits will be small, of low quality and not very nutritious.
It is important to know the types of thinning that we can use, also when, how and why we should perform the thinning of fruit trees. Some trees that are commonly thinned are: apple tree, pear, plum, peach and citrus.
Reasons to perform the thinning of fruit trees
Deciding which fruits should be removed is no easy task. Proper selection must be made so that the harvest is not affected. There are several reasons to perform the thinning of fruit trees, some of them are:
- Fruits of better quality and larger size are obtained
- Release the weight of the tree to increase production and prevent the breaking of branches
- Thinning allows the tree to receive more sunlight, improving fruit ripening
- Allows a better development and growth of the tree, as well as its shoots
- Prevents stunted growth of the fruit tree, caused by very frequent harvests
- Reduces the spread of pests and diseases
- The risk of biennial trend, where the tree bears fruit every two years, is avoided.
- Decreases premature fruit fall
When to perform the thinning of fruit trees
Thinning should begin in early summer and culminate in mid-July, as this produces an increase in the size of the remaining fruits. It is recommended to lose weight after pollination and in the early stages of fruit development; this is usually before the young fruit exceeds 3 centimeters in diameter.
There is a phenomenon called the fall of June, where the trees will spontaneously shed their fruits. We must take advantage of this moment to perform the thinning, cutting the youngest fruits, being careful not to overdo it.
How to perform the thinning of fruit trees
We don’t need to be experts to perform the thinning. Although there are different techniques, the cutting of the fruits can be done in a simple way with sharp scissors, a small shunt pruner or simply with the hands. If you use your hands twist the fruit gently instead of pulling it, to avoid damaging the branches.
There are two fundamental steps to perform the thinning of fruit trees: Observation and elimination. In the observation we must perform a reevaluation while pruning, here we detail the damaged or weak fruits and identify signs of the presence of pests, such as excrement and larvae.
For elimination, we select one or two fruits per bunch, the largest and healthiest should be taken. After making this selection, pruning will be done on each branch, leaving only the strongest fruits which will develop completely full of vitamins and flavor.
Types of thinning of fruit trees
There are several types of thinning namely: natural thinning, manual thinning, chemical thinning and mechanical thinning. Each of them applied with the purpose of improving the harvest.
It is the discharge of fruits that the tree performs naturally, without human intervention. With natural thinning the tree tries to maintain a balance and sheds some fruits that interfere with its development and growth.
In this process, the fruits with spots, cuts, irregularities and smaller size are removed. Pruning is mainly carried out on the outer branches to prevent them from bending and breaking, pruning must be balanced throughout the tree maintaining a separation between the fruits and avoiding contact between them. Hands or scissors can be used.
Chemical thinning is done with hormonal products, however it is not advisable. This technique still requires a lot of research. The application of chemical thinning helps mainly in the elimination of pests, it is generally used as biological control.
Este sistema de adelgazamiento es usado en plantaciones comerciales. Las frutas se eliminan del árbol mediante chorros de agua a presión, vibradores y peines de púas.
5 árboles frutales que necesitan aclareo
Cierta variedad de árboles frutales, son más propensos a producir cada dos años si no se adelgaza la cosecha de frutas del presente año. Algunas especies de árboles tienen mucha carga de frutos en un año y al año siguiente una carga muy baja.
Sin embargo esos períodos de superabundancia generan frutos cada vez más pequeños. A este tipo de árboles es necesario realizarles un aclareo. Como vimos anteriormente los más propensos son: manzano, peral, ciruelo, melocotonero y cítricos.
El mejor momento para el aclareo de los manzanos es 30 días después de su floración máxima. Para adelgazar las manzanas, debemos dividir los racimos para poder seleccionar bien la fruta. Elimine las frutas mal formadas dejando la fruta ‘rey’ en el centro del racimo.
Es aconsejable dejar alrededor de 15-20 centímetros entre la fruta restante. El aclareo puede hacerse con tijeras de podar o con los dedos pulgar e índice.
Pear trees generally need less thinning. But if you notice that your healthy pear tree drops the fruit when it’s still small and not ripe, or has a tendency to be biennial every two years, consider thinning as a remedy.
Remove small, deformed, or injured fruit as soon as it appears. Leave two fruits for each bunch with a distance of 10-15 centimeters between the remaining fruit.
Plum is particularly prone to overexploitation, so thinning is vital. These trees have a tendency to have clusters along the branches and with their weight they usually break.
When the fruit is large enough to be easily picked, it is necessary to break the bunches, leaving room for the fruit to grow and help prevent premature fall. Leave about 10-15 centimeters between the remaining fruit.
These fruit trees tend to give very heavy fruit harvests, which can damage the tree. It is very likely that the thinning should be routine in the peach tree. It also happens with peach or nectarine trees that due to the weight run the risk of their limbs breaking and tearing the bark.
Leave at least 15 centimeters of space between the remaining fruit. Thin peaches every 10 cm when they are the size of a hazelnut, then every 20-25 cm when they are the size of a walnut.
Thinning citrus fruits to improve the size and quality of the fruit should be done after the natural fall of the fruits, starting with the smaller fruit. Removing 20% to 30% of the remaining fruit.
Robert Asprin, APD is a non-dieting Accredited Practicing Dietitian passionate about inspiring positive changes in eating and lifestyle behaviors to help improve health while nurturing relationships with food and body.