Choosing a position for cultivation
aronia adapts easily to different environment conditions. Therefore, it can be grown all over the country, including piedmont regions (where it is most successfully grown on north or north-west slopes). When choosing the position, you have to remember that aronia is a photophilous plant which needs good lighting to produce regular annual crops.
The annual demand for water is 500-600 mm of rain, but aronia is quite tolerant to both to poor moisture as well to excessive dampness. Owing to its root system structure, aronia is successfully grown in the soils with low- and high-level ground waters. Long periods of draught can affect the yield and the quality of fruit (which may then turn bitter), especially in the summer, at the time of the intensive growth of the fruit.
Generally, it is not recommended to grow aronia together with other fruit trees or shrubs. High yield is obtained only on homogeneous plantations of the area of minimum 1 ha, where machines can be used in the cultivation process.
Aronia is most successful in rich and airy soils with high water capacity. However, with adequate fertilizing and care high yields have been also found on lower class soils (class 5 or even 6). Stony and gravel soil, as well as marshy or saline soils, are of little use. aronia grows well if the lower layers of the soil consist of sandy clays with good aeration and sufficient water retention capacity. It is less successful if the lower layers of the soil are heavy clays, where excessive water retention occurs, which in turn has a negative effect on the development of the root system.
Preparing the soil
A well prepared soil before starting the plantation is fundamental and will have an impact on the beginning of fruiting.
In the first place, the area must be cleared from weeds, which will make the cultivation of the seedlings easier in the first years because aronia is particularly sensitive to weeding. At the age of 4-5 years, aronia is strong enough to choke weeds out.
One year before planting the seedlings, you must check the soil acidity and, if needed, bring the acidity down to Ph 6-7 through lime treatment. In the vegetation season preceding the planting it is recommended to apply a soil cover with papilionaceous plants for early plough-up. The fundamental treatment is a deep plough which should be preceded by phosphoric fertilization in order to introduce the not easily shiftable phosphorus into the deeper layers of the soil. For poor soil organic manuring is recommended before planting aronia.
Starting the plantation
The distribution of the shrubs on the plantation must allow for machine work. Therefore on large plantations the recommended interval between rows is 4 m. The spacing of seedlings in a row can be ca. 1.5 m. Large plantations should allow for machine harvesting in the future and therefore the seedling spacing in a row should be 0.6 - 0.8 m. It must be remembered that the plantations with densely planted shrubs for machine harvesting will give double the yield in the first years of fruiting, which will quickly compensate for the higher cost of starting the plantation.
The aronia's seedlings for permanent planting should be homogenous, preferably two-year or well-developed one-year plants. After they have been removed from the nursery (which is usually done in October), the material should be heeled in, preferably close to the planting site. You should avoid overdrying and freezing of roots, which has a serious impact on the percentage of successful establishment of the seedlings. Healthy, strong and properly secured seedlings guarantee one hundred per cent establishment.
It is analogical to that used in most fruit shrubs and trees. After the rows and planting points have been marked out, holes are dug in - the poorer the soil, the deeper the hole. With poor soils it is recommended to prepare the holes by adding manure, hotbed soil, deacidified peat or compost dressing. You must make sure that the roots are well spread and have no immediate contact with the manure. The seedling should be planted 3-5 cm deeper than it grew in the nursery, which will enhance shrub spreading. After the seedling is planted, a little hollow should be left around it to help retain water near the roots. With large plantations planting machines should be used to significantly speed up the pace of work.
Cultivation of plantings
The main method of soil maintenance in young plantings for the first two years is black fallow. For the first two years the inter-rows can be used to grow vegetables and papilionaceous plants (no cereals are allowed in inter-rows). Starting from the third year, inter-row sodding is recommended with herbicide fallow in the rows. In ecological plantations herbicides are not used and the weeds in the rows must be combated mechanically.
Fertilization should be preceded by the lab tests of the soil. A good sign of the sufficient amounts of nutrients is the dark colour of the large leaves, their density on the shoots and a significant growth of the shrub.
Small and pale leaves indicate inadequate soil nutrients or an excessive density of the shrubs, root freezing or draught. aronia can be fertilized using natural (organic) or mineral fertilizers. Natural fertilizers are dung or liquid manure. With mineral fertilization you must remember that not easily shiftable fertilizers, such as phosphorus and potassium, should be applied in the autumn or very early spring, while nitrogen fertilizers are recommended twice or three times throughout the vegetation season, starting in April and the last one in June. The estimate quantities of a pure nutrient in the fertilizer are as follows: P - 80 to 100 kg/ha, K - 100 to 150 kg/ha, N - 100 to 150 kg/ha.
It is one of the most important procedures, the purpose of which is thinning and removal of weak or damaged shoots. Cutting is recommended in the winter (February, March). In the first place, cut such shoots which make harvesting difficult (creeping or blocking the rows) and any damaged shoots. Then, remove parts of any old shoots that choke the plant and the excessive number of young sprouts, laving only the most healthy of them, which will replace the old shoots in the future.
aronia does not cause many problems because so far there have been no pests or diseases in such a quantity to endanger our plantations. Occasionally, aronia, its young shoots in particular, is attacked by aphids or leaf-eating caterpillars. In such cases, a one-time spray with one of the available insecticides should be applied. In ecological plantations, where no insecticides are used, the nature itself successfully combats the pests - as proved throughout many years of observations - by increasing the population of beneficial, pest-combating organisms.
In Poland, aronia ripens in late August, depending on the environmental and weather conditions. The ripening season may vary by two weeks. There is one-time harvest, which is started when all the fruit are completely formed and well-coloured. The containers must not be overfilled, otherwise the fruit may get crushed. Aronia fruit are persistent and can be stored unharmed in the containers even for a few days. It is a significant advantage because it makes it possible to make a one-time delivery of the fruit harvested from a large area to the processing plant. For mechanical harvesting with the use of a currant harvester, the right harvesting time is very important so that the fruit can be easily pulled off the pedicle. In our area aronia is harvested in late August or early September.
Chokeberries are used as an excellent flavouring to various fruit products such as wines and juices as well as jams, jellies and all sort of confectionery stuffing. The fruit are also processed into glazed chockeberries and a natural red colouring used in food industry.
The processing of fresh aronia is not difficult. Although the fruit soft, their shock-resistance allows to store them for a long time. aronia products have got a characteristic slightly tannic taste, a beautiful ruby colour and they maintain their medical characteristics.
aronia fruit contain may vitamines, with an outstanding proportion of vitamine P of which the plant is considered to be the richest source in the world. This unusual content of vitamin P, so uncommom with other fruit, gives good grounds for pronouncing aronia a medical plant. The fruit, juice and products made of aronia may be recommended in the treatment of hypertension, arteriosclerosis, hemmorrhoids, gastritis and also radiation sickness.
For more details apply to PPH "EGGERT" My firm deals with the production and marketing of the highest quality plant material as well as the sales of fresh and frozen aronia fruit along with aronia products.
Chemical composition, therapeutic values and usefulness for food processing
The growing interest in aronia owes to the unique properties of its fruit, which are excellent raw material for processing and are classified as medicinal plants for their chemical composition.
The chemical composition of black aronia fruit may slightly vary depending on the region and the weather conditions during the vegetation period. Fresh, ripe aronia fruit contain 74-83% of water and 26-17% of dry mass respectively. aronia fruit contain ca. 18% soluble substances, such as sugars, acids, tannins, pectins, pigments and mineral salts. The biggest share among the soluble substances are sugars, whose total content in the fresh fruit mass is 6.2-10.8%, where 4.3-5.9% are monosaccharide, fructose and glucose, while the rest is saccharose.
The content of organic acids in black aronia fruit is relatively insignificant - expressed in malic acid it is 0.7-1.3%. Thus, the sugar/acid ratio is quite high and it is ca. 8.
The presence of tannins contributes to the flavour of aronia fruit, the content of which in ripe fruit is ca. 0.35%. Tannins give the fruit their characteristic flavour, so much valued in food processing industry, winemaking in particular.
Black Aronia fruit show high contents of pectin substances (between 0.63 and 0.75%) and therefore can be used for jelly products and marmalades.
The content of ashes is higher than in other berries, such as currants, raspberries or gooseberries, i.e. 1.55 g of ash substances per 100 g of fruit. Ash substances contain significant amounts of calcium (ca. 7.8%) and very valuable microelements, such molybdenum (0.32-1.88 mg%), manganese (3.66-9.64 mg%), copper (0.81-2.97 mg%) and boron (0.15-0.71 mg%).
Due to its valuable content of vitamins, aronia is qualified as a medicinal plant, particularly useful in the treatment of civilization- related diseases, such as cardiovascular diseases, gastritis and - as demonstrated in the recent studies - aronia fruit help neutralize the detrimental effect of radioactive radiation on a human body.
Aronia fruit also contain vitamins: P, C, PP, B2, B9, E and carotene (pro-Vitamin A). Among those, the content of Vitamin P is incomparably high compared to other fruits - it varies between 1200 and 3977 mg% in fresh fruit, 2500-3500 mg% on the average. In aronia fruit Vitamin P appears in the bioflavonoid group of: colourless catechin 600-1500 mg%, red anthocyanins 600-1300 mg% and insignificant amounts of yellow flavonoids.
Owing to such a high content of P-active compounds, aronia fruit and their preserves are used in the treatment of certain conditions. Effective 4 April 1959, the Pharmacological Board of the former USSR Ministry of Health recommended black aronia fruit and juice for wide clinical use in the treatment of hypertension, arteriosclerosis and gastritis. In 1966 industrial scale production of Vitamin C+P started, with ascorbic acid and Vitamin P obtained from dried aronia pomace (containing 16600-18250 mg%) as a raw material. This medical product is recommended in the treatment of haemorrhoids, capillary conditions, haemorrhages and - in the first place - hypertension. In Poland, aronia juice is the basis for geriatric drugs.
The contents of vitamins in aronia fruit are as follows: Vitamin C 14-28 mg% (max. up to 50 mg%), carotene (pro-Vitamin A) 1.8-2.5 mg%, B2 0.1 mg%, B9 0.05-0.1 mg%, E 0.5-0.8 mg%, PP 0.6-0.8 mg%.
Juice extracted from fresh aronia fruit (7-9% sugars, 0.8-1.1% acids, ca. 400 mg% Vitamin P, all the above mentioned vitamins and microelements, as well as small amounts of yeast and natural antibiotics) is widely used in medicine and food processing. With fresh fruit the juice extraction rate is ca. 75%, and with frozen fruit it increases up to 80%. With the addition of sugar, aronia juice tastes nice and can be used both for immediate consumption and for jelly desserts, colouring and as an additive to carbonated waters and other drinks. Natural aronia juice has an intensive and clear ruby-red colour, which makes it ideal to blend with colourless juices, e.g. apple juice, which is of particular value in winemaking.
Fresh aronia fruit can be widely used in food processing, particularly as a colouring and vitamin additive to other common and less valuable fruit. Preserves, jelly desserts, jams, marmalades, confectionery fillings and other products have a nice and unique taste and a beautiful colour. Particularly valuable are the preserves, in which the P-active compounds can be conserved almost intact and one tablespoon of aronia preserves meets the daily requirements for Vitamin P. Candied fruit, used in confectionery, have similar properties.
Dried aronia fruit are also a valuable raw material, from which - when properly dried - a beautifully coloured therapeutic extract can be prepared. 50 g of dried fruit can supply a therapeutic daily dose of P-active compounds in the treatment of above mentioned conditions. As a preventive measure, dried aronia teas or in composition with other dried fruit (e.g. rosehip or hawthorn) can be used.
Last but not least, the pomace from the juice extraction process is used to extract pigments. As a waste product, pomace can be a valuable material to obtain natural ruby-red dyes. Natural dyes are now becoming more and more popular in food processing industry as the use of synthetic dyes becomes less common.
Piotr Eggert, MSc. Eng.