Growing a renegade fruit

Photos by John Hibma.
Allyn Brown in the orchard.

Located in Preston, Conn., is the largest grower of black currants in North America. Maple Lane Farm has been growing the black currant commercially since 2000, with its first harvest in 2003. This year, Owner Allyn Brown expects to harvest around 200,000 pounds of this special berry. Nearly all of his black currants are pressed for juice and bottled under his Connecticut Currant label.

The black currant was originally a native crop to North America, and was federally banned for many years in this country. According to Brown, around 1900 it was learned that the currant was an alternate host of white-pine blister rust, which was damaging the white pine forests. The government banned the black currant along with its related species, gooseberries and red currants, all part of the Ribes family (pronounced rie-bees). In 1966, recognizing that black currant was a native plant, the government lifted the federal restrictions and left it up to the individual states to decide if they would allow ribes to be grown. In the mid-1980s, Connecticut began allowing currants and gooseberries to be grown in the state. Still today, Massachusetts and Rhode Island do not allow black currants to be grown, and New York allows them only on a limited basis.

Maple Lane Farm is spread over 150 picturesque acres and Brown has been farming there since 1978. After graduating from the University of Connecticut, he started with Christmas trees and blueberries, raspberries and strawberries. He later added apples, and for a number of years grew the oyster mushroom for a nearby mushroom company. Today, there are about 100 acres devoted to black currants in varying stages of growth.

Once plants have matured, the crop typically yields about 5,000 pounds to the acre and is harvested in July. Brown picks the currants with a mechanical harvester. The plant begins to bud in May, and is a self-pollinator, not requiring the need for bees; however, bees do help. Brown exclusively grows the Titania variety, which is resistant to the white-pine rust. He starts new plants from rooted cuttings taken from older plants, which are then planted in the spring. The plants take three to four years to mature. This past winter, because southern Connecticut had little snowfall and a lot of freezing rain, a field of new plantings was killed by excessive ice and frost heaves, which pushed the new plants up and out of the ground.  

While the black currant is a relatively unknown fruit in the United States, it’s popular and widely grown in Europe and England. In the United Kingdom, black currant juice is the equivalent to our orange juice. A well-known brand of black currant juice in England is called Ribena, and it has been around since World War II when it was developed as a source of vitamin C for the troops, as oranges were difficult to get. Black currants have four times the vitamin C of oranges, and are also valued for their antioxidant properties. The black currant, which is about the size of a large blueberry, is not consumed whole like most other berries due to its strong flavor.

Brown researched the crop and its potential markets for years before he decided to begin cultivation. And, as the juice continues to grow in popularity for its high vitamin and antioxidant properties, Brown’s market has expanded throughout the mid-Atlantic states. He’s recently begun experimenting with a black currant/apple juice combination, black currant/cranberry and a black currant/blueberry juice. You can find his products in many major grocery chains in New England.

Europeans and Canadians distill the juice of the black currant into a cordial or liqueur called cassis, which is popular as an aperitif or after-dinner drink. Brown sells a small amount of his currant crop to a cassis distiller in Canada.

A handful of ripened black currants.
 
The bottling line.
 
Erica Teveris takes a stem cutting for lab analysis of borer larvae.
 
Erica Teveris takes a stem cutting for lab analysis of borer larvae.
 
Lorraine Los showing a stem that is most likely afflicted with the Botryosphaeriafungus. Note the lack of vegetation on the stem.

The only part of the manufacturing process that Brown doesn’t do at his Preston farm is the actual pressing and juicing of the currants. Instead, he ships his berries to a processor in Massachusetts who is better suited to do that. The ripened black currant berry holds up well to freezing after it’s picked, allowing it to be stored and processed all year long. The berries are pressed on an as-needed basis and the concentrate is returned to the farm for bottling.

At the bottling facility, the concentrate is blended with filtered water and a natural fructose sweetener and then pasteurized. The finished product is 20 percent juice and bottled in 16-ounce and half-gallon plastic containers. Once boxed, the juice is immediately chilled in cold storage and ready to be shipped.

According to Brown, the black currant is not a particularly difficult fruit to grow, but it continues to be a learning experience for him. One challenge that has emerged is a pest called the currant borer. This insect lives its life as both a moth and a larva. The larva burrows into the stem, living for about a year there before emerging as an adult moth. The moths emerge late in May, and are out for six to eight weeks, mating and laying eggs on the currant plant stems. When the larvae hatch they immediately bore into the stem. A heavy enough infestation of larvae in a plant will eventually kill it. Once they’ve bored into the stem the larvae can’t be killed.

Brown has been working with the University of Connecticut’s Cooperative Extension System to incorporate an integrated pest management (IPM) program to control the borer and limit pesticide applications. Lorraine Los, from UConn’s College of Agriculture and Natural Resources, has been coordinating the IPM program at Maple Lane since 2005. She says that the primary strategy in controlling the borer is through mating disruption of the moths. In mid-May, Los and her team begin installing pheromone applicators in the orchard. The applicators resemble a simple twist tie, but have been coated with the pheromone of the female moth. As the pheromone disperses throughout the orchard, the male moths are confused and unable to find the females, thereby disrupting the mating. Los installs 200 of the ties per acre in parts of the orchard. The hope is that the mating disruption of the moth will be significant enough to reduce the infestation threshold to a manageable level that will allow the plants to be fully productive and healthy while keeping the application of pesticides to a minimal level. Some of the farm’s original plants were so heavily infested that Brown mowed the plants down, hoping that as they grow back, they will continue to be healthy and productive. Those plants will take two years to grow back to a productive size.

The size of the Maple Lane currant orchard allows Los to use it in a controlled research study with the mating disruption. As part of that study, this year she’s taking cuttings of plant stems with the help of students like Erica Teveris, who’s working on a degree in biology and environmental science at Northeastern University in Boston. As part of her studies, Teveris is working for the UConn IPM program this year and, along with other IPM projects she’s involved with, will dissect the stems to determine the level of infestation of different plants at different stages of growth. Los explains that the dissection of the stems allows her to compare infestation levels in the mating disruption plots versus the “control” plots where no mating disruption is used this year.

It’s a bit of a mystery as to where the currant borer came from. Los thinks it may have come from wild currants that grow in New England. She explains that because the black currant is such a “new” crop in the United States, little is known about pests or diseases affecting the plant. At this point, there are pesticides approved for use on the black currant by the EPA, but it’s not known if any of them work on the currant borer.  Los has to figure out how to control the currant borer and her research with black currants is basically on the cutting edge here in the United States.

In 2006, growers in New York identified a fungal disease on their black currant plants, and in 2007, a UConn plant pathologist identified it in the Maple Lane currants, as well. The fungus is called Botryosphaeria, and it affects the outer tips of the stems of the currant plant. It appears to establish itself about 10 to 12 inches down the stem, killing the outward portion from that point. While the fungus is not widespread in the Maple Lane orchard, it has significantly affected a couple of the fields. Los is now collaborating with Dr. Kerick Cox, Cornell University, on research trials for this disease at Maple Lane.

In the meantime, Brown is eager to establish and expand his markets for black currant juice. The research work at Maple Lane Farm will certainly help this fledgling industry get better established in the United States. You can visit Maple Lane’s Web site at www.maplelane.com.

The author is a freelance contributor based in Connecticut.