What solutions are there against spring frost on apricot trees?

The apricot tree is a fruit tree appreciated for its early flowering and sweet fruits. However, this precocity makes it vulnerable to late frosts that can compromise the harvest. Every year, producers face unpredictable climatic episodes that threaten the formation of fruits. This problem is accentuated by global warming, which causes milder winters and an early vegetative recovery, thus increasing the risks of exposure to spring cold. Find out what the risks of frost are on apricot orchards and the natural solutions developed by Agrobiotop to strengthen your trees against these spring frosts.

The apricot tree, a fruit tree very sensitive to frost

Native to Asia, the apricot tree is a tree accustomed to hot and dry climates . When mature, it can withstand temperatures as low as -20°C or even -25°C. Its real weakness lies in its early flowering, which generally occurs between February and March , a period when night frosts are still frequent. Unlike other fruit trees such as the apple or pear tree, which flower later, the apricot tree exposes its buds to negative temperatures when they are most fragile.

Climate change is exacerbating this problem. Milder winters lead to an earlier rise in sap and therefore to an earlier flowering . When a cold snap occurs later, it can wipe out some or all of the future harvests. Producers must therefore be extra vigilant and implement effective protection methods to limit losses.

What are the effects of frost on flowers and fruits?

The impact of frost varies depending on the stage of development of the flowers and young fruits. The more advanced the flowering, the greater the risk of damage. As soon as the buds begin to swell, a temperature of -4°C is enough to destroy them. When the stamens become visible, exposure below -3°C causes serious damage. A fully open flower cannot withstand -2°C, and petal fall accelerates as soon as the thermometer approaches 0.8°C.

Young fruits are even more vulnerable. Below -0.5°C, they undergo internal alterations that do not manifest themselves immediately. Black spots gradually appear inside, while a ring of frost can form on their skin. This deterioration, invisible at first glance, compromises their development, and many fruits end up falling prematurely.

The apricot tree goes through several stages of development in spring, and each of them has a specific sensitivity to negative temperatures. The more advanced the flowering, the greater the risk of destruction by frost.

• Swollen flower buds : from -4°C, these still closed structures suffer irreversible damage, compromising flowering even before it opens.
• Appearance of the stamens : when the reproductive organs begin to appear, a temperature below -3°C is enough to damage them, thus limiting pollination.
• Fully open flowers : Frost becomes particularly critical at this stage. From -2°C, floral tissues freeze, preventing fertilization and greatly reducing fruit production.
• Petal fall : Even after pollination, a temperature of 0.8°C can cause degradation of the still fragile structures, which increases the rate of loss.
• Young fruits in formation : exposure below -0.5°C causes internal alterations which compromise their development.

A fruit affected by frost does not always show immediate signs. Over time, anomalies appear:

• Internal black spots that often go unnoticed in the first few days but gradually alter the quality of the fruit.
• A ring of frost that gradually appears on the surface, indicating tissue deterioration.

How to protect the apricot tree against spring frosts?

There are several methods for limiting these risks, whether it is the choice of planting location, physical protection or even thermal techniques.

Optimize location and growing conditions

The choice of planting location directly influences the resistance of the apricot tree to late frosts . A sunny location protected from cold drafts reduces the risk of prolonged negative temperatures.

Low areas , especially valley bottoms or the hollowest parts of a garden, should be avoided. Cold air, which is heavier than warm air, tends to accumulate there, which increases the risk of frost. Planting an evergreen hedge high up can provide a natural barrier against the descent of cold air and improve the microclimate around the trees.

Use thermal techniques

Placing heat candles between trees raises the ambient temperature and protects the buds from frost. This technique is effective, but it requires significant logistics and represents a high cost in terms of labor and materials. Other devices, such as wind towers, are sometimes used to stir the air and homogenize the temperature. Their effectiveness depends on weather conditions and local thermal variations.

 Use natural solutions

Capture moisture from the air to prevent spring frosts using sodium bentonite clay as a powder or foliar spray ( Bentobio ).

Avoid stagnation and penetration of rain and irrigation water into the orchard ( Siliboost )

Choose frost-resistant varieties

Some varieties of apricot trees have a later flowering period, which reduces their exposure to spring frosts. The choice of cultivar is strategic, especially in regions where temperatures remain cool until spring.

Agrobiotop solutions against spring frost on apricot trees

• BENTOBIO (Application 24 to 48 hours before frost, dusting or foliar spray)
• SILIBOOST (For aeration, decompaction of soils and prevention of water stagnation)

Photo : Shutterstock