By Connie Hardy, content specialist, AgMRC, Iowa State University, chardy@iastate.edu, and based on a report by Eldon Everhart, Iowa State University Extension.

Revised June 2012 by Joe M. Hannan, Iowa State University Extension and Outreach, Commercial Horticulture Field Specialist, jmhannan@iastate.edu.

Overview

Aronia (Photinia melanocarpa, formerly Aronia melanocarpa) is commonly known as “black chokeberry,” although the preferred common name used by individuals who sell the berries or products made from them is “black aronia berry” or simply “aronia.” Aronia is a woody perennial shrub in the rosaceae family that is native to the eastern United States and hardy to zone three. It grows in full sun and along woodland edges. In recent years, most of its native habitat has been lost to field crops and urbanization (Hardin 1973).

Aronia is a plant that has benefited from increased interest in phytonutrients, plant compounds that have beneficial effects on human health. Evidence of health benefits is accumulating from large population studies, human feeding studies, and cell culture studies. Interest in “eating healthy” has led to worldwide growth in the popularity of aronia berries and products made from them. This in turn has led to the planting of aronia as an alternative cash crop in the Midwest (Trinklein 2007).

This plant should not be confused with chokecherry (Prunus virginiana), which is also a native American plant somewhat similar to aronia in appearance, but whose leaves, stems, and seeds contain toxic amounts of prussic acid (Trinklein 2007).

Plant Profile

Aronia plants are long lived and survive for several decades. They are deciduous woody shrubs with 40 or more stems per bush at maturity (Trinklein 2007). They tolerate full sun or partial shade; however, in commercial plantings, full sun is recommended for uniform fruit ripening. They are well adapted to a wide range of soil drainage classes from poorly drained to excessively well drained but, they will do best in well-drained soils.

Aronia produces loose clusters of 10 to 15 berries at the ends of shoots. Individual berries are firm and about one-quarter inch in diameter. The fruit ripen in September and have a long harvest window of four to six weeks (Hardin 1973). Although the fruit is often referred to as a berry, the plant is closely related to the apple and the fruit is a pome, not a berry. Unlike apples, aronia is self-fruitful and does not require a pollinator for fertilization and fruit set; therefore, only one cultivar is required for fruit production.

Like other fruit crops, aronia develops its next season’s fruit buds while maturing its current season’s crop; hence the grower is always managing two crops at once. Aronia has a chilling requirement, meaning that a cold period, or rest, is required before flowering. Actual chill requirements have not been determined.

Fertility

Because fertility guidelines for aronia are not well established, guidelines for apples are often used due to their close botanical relationship. Iron deficiencies have been observed in commercial plantings in the Loess hills of Iowa where the soil pH is often greater than 7.2.

Pruning

Pruning is required to keep plants at a manageable size and to maintain yields. Similar to blueberries, as shoots age they become less productive. For maximum yield, annual removal of shoots or stems greater than one inch in diameter is required. Plants should be pruned during late winter or early spring before bud break. Alternatively, the entire plant may be cut back to the ground every ten years and reestablished. Unlike annual pruning, this method will force the plant out of production for several years as the plant reestablishes itself.

Spacing

Plant spacing is largely dependent upon how the plants will be harvested. For hand harvest, rows may be spaced as close as eight feet on center and six to eight feet within the row. This close spacing provides enough room to walk around and harvest fruit from all sides of the plant, but may not provide enough room for a vehicle to drive between the rows. For mechanically harvested fruit, a minimum of ten feet on center is required to get equipment through the rows. Twelve to 14 feet on center is recommended. In-row spacing for mechanically harvested aronia may be as close as three feet on center for hedge type plantings or six to eight feet on center for an individual plant system. A minimum of 20 feet on row ends is required to maneuver harvest equipment. Aronia growers who currently harvest mechanically claim less fruit drop during harvest using the hedge type system over the individual plant system.

Cultivars

Wild aronia is different from the cultivated varieties we grow today in commercial production. Commercially important cultivars in Europe and the United States include Nero, Rubina, Viking, Hugin, Galicjanka, Hakkija, Ahonnen, Kurkumacki, Serina, Morton (also marketed as Iroquois Beauty) and McKenzie (Jeppson 2000; Strigl et al. 1995). New research indicates cultivars such as Nero, Viking, and McKenzie were developed in Eastern Europe and are crosses between Photinia melanocarpa and Sorbus aucuparia (European mountain ash) and that there is very little genetic diversity among cultivated aronia (Smolik et al. 2011). In fact, ‘Nero’, ‘Viking’, and ‘Galicjanka’ are nearly identical when compared through genetic markers (Smolik et al. 2011). Galicjanka, a newly emerging cultivar developed in Poland, is marketed to producers as having a condensed ripening period. This is a highly desirable trait for mechanically harvested fruit to ensure uniformity across the field.

Pests

Contrary to common belief, commercial plantings of aronia are not immune to pests. Wildlife including deer, birds, rabbits and small rodents may be a problem. A deer fence is essential for most new plantings to prevent browsing on young plants. Aronia releases a natural chemical to deter deer from browsing, but it is often not sufficient to protect the plant. Similar to other fruit crops, birds will typically not eat the fruit until it is nearly ripe. Various forms of netting and netting machines are available for purchase or construction if birds become a pest. Observed insect pests include apple maggot, brown marmorated stink bug, cherry fruit worm, grasshoppers, Japanese beetle, soft fly and tarnished plant bug. These pests are not active in all regions of aronia production, so scouting is important to determine if management is required. Observed diseases include cedar-quince (or hawthorn) rust and cedar-apple rust. Weeds in aronia plantings are often controlled through mulching or mowing. For maximum weed control, reduce the weed seed population before establishing aronia plants.

Harvesting

The berries can be harvested by hand or with a mechanical harvester. In Europe, aronia is often harvested with a machine similar to the blueberry harvesters in the United States (Trinklein 2007). Oxbo® International Corporation offers the Korvan®line of blueberry harvesters that include self-propelled and tow-behind models. Oxbo® has manufacturing locations in New York, Wisconsin and Washington. Weremczuk Agromachines® has developed the Joanna 3 half row and Victor full row aronia harvesters. The Victor is available as a pull behind or a self-propelled model. Both the Oxbo and the Weremczuk are currently in use in the Midwest.

There are currently no established industry standards or harvest guidelines. For fresh consumption or juice, brix (or soluble solids) is often used to determine maturity. For wine production, initial juice pH or titratable acidity (TA) may be used. An Oxygen Radical Absorbance Capacity (ORAC) value may be used for other value added products marketed for their nutraceutical value.

Commercial Aronia Production

Aronia has been grown as a commercial berry crop in most Eastern European countries since the 1950s. Large-scale commercial cultivation of aronia started in the Soviet Union in the late 1940s as a means for producing their own source of vitamin C and reached 43,984 acres in 1984 (Kask 1987). According to the Polish Ministry of Agriculture and Rural Development in Warsaw, there were 11,119 acres in Poland in 2004. One year later the number had grown to 12,355 acres. One Polish company alone sold 40,000 tons of aronia juice (Kampuse and Kampuss 2006). In Europe, new business startups that use aronia berries as an ingredient have increased from just two launches in 1997 to 108 in 2007 (McNally 2008).

Two years after planting, aronia shrubs produce about two pounds of berries per bush when planted at eight feet in-row. By the third year after planting, berry production is about 3 to 5 pounds per bush. Production levels off at 15 to 20 pounds per plant by the fifth or sixth year in commercial plantings in Western Iowa. When in-row spacing is halved, yield per plant roughly halves as well. On mature plantings in Eastern Europe, yields as high as 37 pounds per bush have been reported. The average yield is around 23 pounds per bush in Eastern Europe (Trinklein 2007).

The Midwest Aronia Association officially formed in 2009 as a non-profit organization. Their “sole purpose is to investigate, improve, and promote all aspects of aronia growing.” The association has focused on developing a network of growers and partners to promote aronia as well as gather production, marketing, and farm management resources and information for its member growers (Midwest Aronia Association 2012).

Uses of Aronia

Aronia’s high anthocyanin and polyphenol content yield deep reddish-purple hues and color with a strong astringent taste. For juice and food processors using aronia for color, aronia can contain up to 2,000 mg/l of anthocyanins (Janick and Paul 2008). These compounds are also useful in wine making, particularly in dry red wines both for color and astringency. Beverage manufacturers including SoBe®, SunOpta® and Hipp Organics® have included aronia juice in their products.

Many growers have developed other value added products such as jam, jelly, juice, sauce, ice cream and salsa that they sell in addition to fresh or frozen berries in both local and non-local markets. Other vendors offer aronia berries, juices and food products for their nutraceutical properties.

Health Benefits

Aronia is the new “superfood” in town, according to an article in the Wall Street Journal. Antioxidant-containing foods are being recommended by doctors and nutritionists as important additions to a healthy diet (Sepulveda 2008). Scientists now agree that one of the best ways to protect against aging is to consume a diet rich in fruits and vegetables. Even those who manage to consume the recommended five daily servings of fruits and vegetables may not be obtaining enough antioxidant protection to ward off cancer, cognitive decline, and cardiovascular disease (Cherlet 2008).

Medical research has documented many health benefits of aronia berries. Most of the effects of aronia berries are due to their high antioxidative activity (Broncel et al. 2007; Naruszewicz et al. 2007; Olas et al. 2008; Skupien et al. 2008; Valcheva-Kuzmanova et al. 2007). Currently, there is no data in the literature about any unwanted side effects of aronia fruit, juice, or extracts (Kulling and Rawel 2006 and 2008).

Aronia berries top the list of more than 100 foods that have been scientifically tested for antioxidant capacity, according to Dr. Xianli Wu, a researcher at the Arkansas Children’s Nutrition Center in Little Rock. Wu believes aronia berries have a huge potential to be a healthy food. Other researchers have looked at how aronia affects cardiovascular disease, colon and breast cancers, liver failure, and obesity. (Sagario 2008). For more information, see: Antioxidant Activity and Polyphenols of Aronia in Comparison to Other Berry Species, a study of antioxidant compounds found in aronia and other berries (Jakobek et al. 2007).

Nutrient Composition

Aronia berries and products made from them are gaining in popularity due largely to the rising interest in eating healthier foods. The berries are high in vitamins, minerals and folic acids. They are also one of the richest plant sources of phenolic substances, mainly proanthocyanins and anthocyanins. Laboratory tests have shown that proanthocyanins represent 66 percent and anthocyanins represent about 25 percent of total polyphenols. These chemical compounds are water-soluble pigments that give aronia berries their dark purple or nearly black color (Oszmianski and Wojdylo 2005).

Initial tests on aronia grown in Iowa show that the juice has a pH of 3.5, titratable acidity of 8.2 and a total solids content of 6.9 degrees Brix. HPLC analysis showed that succinic acid, malic acid, quinic acid, acetic acid, citric acid and ascorbic acid were present. Glucose, fructose and possibly sorbitol made up the carbohydrate portion of the juice. By comparison, a commercial juice sample from Germany was tested. This juice had a pH of 3.4, titratable acidity of 13.0 and total solids content of 15.4 degrees Brix. HPLC analysis showed that the same acid and carbohydrate compounds were present but in different proportions.

Oxygen Radical Absorbance Capacity (ORAC) values are cited by nutraceutical processors as the most important indicator of juice quality because they are using aronia for its high antioxidant activity components. ORAC is considered an acceptable laboratory method for estimating the antioxidant activity of foods in human tissue. USDA's table of ORAC values lists the value for raw chokeberry (aronia) at 15,280 umol TE/100 g, nearly three times the value in blueberries and blackberries and one and one-half times the value in black currants and cranberries.
 

Sources

Antioxidant activity and polyphenols of aronia in comparison to other berry species. J.J. Strossmayer University of Osijek, Croatia, Agriculturae Conspectus Scientificus, Vol. 72 (No. 4). Jakobek, L., M.Seruga, M. Medvidovic-Kosanovic and I. Novak. 2007.

Aronia: a berry good plant. Missouri Environment and Garden, 13(9):86. Trinklein, David. 2007.

Aronia melanocarpa – black chokeberry. The encyclopedia of fruits & nuts. Jules Janick edition. CABI. 622-623. Janick, J. and R. E. Paul.2008.

Aronia melanocarpa phenolics and their antioxidant activity. European Food Research and Technology 221(6): 809-813. Oszmianski, Janand Aneta Wojdylo. 2005.

Chokeberry (Aronia melanocarpa) - a review on the characteristic components and potential health effects. Planta Medica 74(13):1625-1634. Kulling, S.E. and H. M. Rawel. 2008.

Combination therapy of statin with flavonoids rich extract fromchokeberry fruits enhanced reduction in cardiovascular risk markers inpatients after myocardial infraction (MI). Atherosclerosis 194(2):79-84. Naruszewicz, M., I. Laniewska, B. Millo and M. Dluzniewski. 2007.

Comparative anti-platelet and antioxidant properties of polyphenol-richextracts from: berries of Aronia melanocarpa, seeds of grape and bark of Yuccaschidigera in vitro Platelets 19(1):70-7. Olas B., B. Wachowicz,A. Tomczak, J. Erler, A. Stochmal and W. Oleszek. 2008.

Demand for superfruit aronia rockets. Decision News Media. McNally, A. January 8, 2008.

Die scharze Apfelbeere (Aronia melanocarpa) als natürlicheFarbstoffquelle. Dtsch Lebensmitt Rundsch 91:177-180. Strigl W. A., Leitner, E. and Phannhouser W. 1995.

The disease-fighting power of berries. Life Extension magazine 9:1-2. Cherlet, A. 2008.