Special attention should be given to the location selection for establishing an apricot plantation, as apricots are sensitive to sudden temperature changes, late spring frosts due to early flowering, and very wet and heavy soils.
Ecological Conditions for Growing Apricots
Apricots, unlike other Prunus species, have greater requirements regarding ecological conditions. Although apricots can practically be grown from 50° northern to 40° southern latitude, they give the best results in a limited area.
They thrive best in a moderately continental climate. However, since they are among the earliest to bloom (right after hazelnuts), there is often a risk of newly set fruits being damaged by late spring frosts. Besides frost, cold and wet winds and sudden temperature changes are harmful to the flowers. Apricots do not tolerate growing at higher altitudes and harsh climates.
They are drought-resistant and benefit from frequent air currents and sunlight. High temperatures and heat do not bother them if the soil has enough water or if there is an irrigation system. Vegetation starts at a temperature of 6°C. The critical low temperature for apricot flowers is from -3 to -4°C, and for newly set fruits from -1.1 to -2.2°C. During deep dormancy, they can withstand temperatures down to -30°C. During the growing season, they can endure maximum temperatures up to 35°C (50°C). They have the greatest water requirements in June and July.
Apricots require light-structured soils – sandy loam to loam, well-drained, and deep soils that can allow rooting to a depth of 120 to 150 cm. The soil reaction should be neutral, i.e., around pH 7, and should contain plenty of humus and biogenic elements.
Selection of Location for Establishing an Apricot Plantation
Due to their sensitivity to sudden temperature changes, late spring frosts due to early flowering, and very wet and heavy soils, the location selection for establishing an apricot plantation should be given full attention.
As a great lover of warmth, apricot cultivation is recommended on southern and southwestern exposures where there is enough warmth and sunlight during the day. If planted in a garden, the best location is next to a house or some structure on the southern side. Locations known as frost pockets should be explicitly avoided if planning to plant this fruit species. Apricots live the longest and bear the best quality fruits on light, warm, and permeable soils that are well-drained. On heavy clay and cold soils, apricots suffer from gummosis and are more frequently damaged by frost. Although not a Mediterranean fruit species, apricots thrive best in Mediterranean conditions where winters are mild, which aligns with their biological nature. Excess moisture in the soil is particularly unfavorable, especially if the apricot is grafted onto wild apricot, almond, or peach rootstocks. Therefore, for cultivation on heavier and wetter soils, plum rootstock is more suitable.
Soil Preparation for Planting Apricots
After selecting the terrain, clearing, cleaning, and leveling it, a soil analysis follows.
Based on the soil analysis results, ameliorative fertilization should be carried out with 40 to 50 tons/ha of manure and mineral fertilizers. If humus content is below 1.5%, it must be added. If the soil reaction is not around neutral, pH adjustment is necessary, usually by adding lime. This is followed by deep loosening of the soil to a depth of 80 cm by deep plowing and subsoiling, preferably at the end of summer or early autumn.
Selection of Apricot Planting Material
Since the plantation heavily depends on the quality of the planting material, it is recommended to plant high-quality one-year-old seedlings that are virus-free, with a well-developed root system and mature above-ground parts.
Selection of Training System for Apricots
Since apricots require a lot of light, the choice of training system is influenced by climatic conditions, especially lighting. In continental areas, the most commonly used training systems are vase and spindle bush.
The vase training system has a crown without a central leader and is built from 3 main branches that form a 120° angle between each other. At a distance of 40 to 60 cm from the point where the first scaffold branches emerge, second-order scaffold branches develop, and the second and third rows of branches develop at a distance of 60 to 120 cm from the first-order branches. A specific feature of this training system is that it has good lighting on both the outside and inside, which is extremely important for apricots.
By timely bending the shoots, sharp branching angles are avoided, preventing water from accumulating in the crotches and causing rot. Wider branching angles provide better crown lighting and contribute to better fruit coloration and quality. Pruning should be done as late as possible in spring to delay vegetation onset and reduce the risk of apoplexy (dieback). In the early years of growth, preference should be given to pinching shoots to isolate the tips and stop the growth of undesirable shoots compared to pruning, which then has only a supplementary role. A common occurrence at the beginning of growth is water sprouts, which must be removed by pruning or sometimes used to fill empty parts of the crown if bent in time.
Time and Technique of Planting Apricots
The best time to plant apricots is during the dormancy period in autumn, although they can also be planted in spring. All damaged root parts should be removed before planting, while fine roots should not be shortened.
In well-prepared soil, pits or furrows are dug to a depth of 70 cm. The apricot seedling is placed in such a way that the grafting point is about 10 cm above the ground surface. Loose soil is placed around the roots and must be well trampled. The next layer above the roots consists of manure, applied at a rate of 20 to 30 kg per tree with 0.5 kg of NPK formulation 7-20-30. All added fertilizers are covered with soil, and the tree is watered with at least 30 liters of water. Apricots are planted with a spacing of 3.5 to 4 m between rows and 2 to 3 m within rows.
Maintaining an Apricot Plantation
Maintaining an apricot plantation is similar to that of other fruit species. Weeds within the rows should be removed using herbicides. Between the rows, the most favorable practice is to grass the area, which should be mowed and mulched during the growing season.
Due to apricots’ sensitivity to sudden temperature fluctuations, whitewashing the tree trunks with lime has proven to be an effective measure to reduce the negative impact of sudden temperature changes, which result in bark cracking and tree freezing. In autumn, when weather conditions allow, after the mass leaf drop, it is recommended to use copper fungicides in increased concentrations or a combination of copper with mineral oils. The treatment should be repeated before the late winter or early spring onset of vegetation (using copper during the growing season is phytotoxic for all stone fruit species!).
Pruning Apricots
Regular pruning is necessary to achieve higher yields of good quality fruits. It is also beneficial to stimulate vegetative growth to produce as many long mixed fruiting shoots as possible, which have a longer flowering period and can better avoid spring frosts.
If there are not enough mixed fruiting shoots, some short fruiting shoots are left despite producing smaller, lower-quality fruits. May clusters have the weakest fruiting and can be freely removed. All larger wounds need to be protected with horticultural wax to prevent gummosis and rot. During the growing season, usually in May, all water sprouts, especially those growing at the tips of branches, should be removed by summer pruning. It is recommended to repeat summer pruning several times during the growing season on vigorous trees growing on fertile soil to encourage the tree to set more flower buds. This way, dormant season pruning is avoided, which is the best solution. Therefore, it is best to thin and bend apricot shoots rather than shorten them (no pruning to buds or similar) during flowering and the growing season.
Irrigating Apricots
Maintaining an apricot plantation is similar to that of other fruit species. Weeds within the rows should be removed using herbicides. Between the rows, the most favorable practice is to grass the area, which should be mowed and mulched during the growing season.
Due to apricots’ sensitivity to sudden temperature fluctuations, whitewashing the tree trunks with lime has proven to be an effective measure to reduce the negative impact of sudden temperature changes, which result in bark cracking and tree freezing. In autumn, when weather conditions allow, after the mass leaf drop, it is recommended to use copper fungicides in increased concentrations or a combination of copper with mineral oils. The treatment should be repeated before the late winter or early spring onset of vegetation (using copper during the growing season is phytotoxic for all stone fruit species!).
Harvesting Apricots
In Croatia, apricots are harvested from June to the end of July.
Most commonly, it is a manual harvest as there are no machines for mechanized harvesting yet.
