Arkansas Democrat-Gazette

UA tests ef­fect of trel­lises on berries

- NATHAN OWENS Agriculture · Fruits · Industries · Healthy Food · Healthy Living · Ukraine · University of Arkansas · Arkansas · RCA Nashville Records · West Virginia · Virginia · Lee · United States of America · University of Arkansas System · Clark · Oklahoma · Ozark, AR · Clarksville, AR · U.S. Agriculture Department · Society of Chemical Industry

The sum­mer sun makes black­ber­ries a gam­ble for farm­ers in the South, com­monly turn­ing the fruit odd shades of red, or white, from over­ex­po­sure.

Most shop­pers won’t see the white ones, be­cause gro­cers will re­ject them before they hit stores, said Amanda McWhirt, extension hor­ti­cul­ture spe­cial­ist for the Di­vi­sion of Agri­cul­ture at the Univer­sity of Arkansas.

As a way to en­cour­age sus­tain­able black­berry pro­duc­tion and pre­vent fruit- re­lated dis­eases or in­sect dam­age, McWhirt is re­search­ing the ef­fects of ro­ta­tional trel­lises on black­berry growth in the Ozark re­gion.

The ro­tat­ing cross- arm trel­lis, or RCA, al­lows black­ber­ries to not just grow ver­ti­cally, but at an angle or near hor­i­zon­tally as well. This of­fers full shade cov­er­age for black­ber­ries, solv­ing a sig­nif­i­cant prob­lem for south­ern grow­ers.

Orig­i­nally de­vel­oped by a hor­ti­cul­tur­al­ist in West Vir­ginia in 1992, the RCA trel­lis was in­tended to pro­mote black­berry growth in

ar­eas prone to harsh win­ters. By ro­tat­ing the black­berry plants so they lie hor­i­zon­tally, grow­ers are able to lay row cov­ers, or blan­kets, over their crops to help en­dure frigid cli­mates, McWhirt said.

In Arkansas, farm­ers face a dif­fer­ent dilemma.

“In the South we have an is­sue with things get­ting too hot in the sum­mer,” McWhirt said. “So we thought, is there a way to ori­ent the berries so they’re al­ways in the shade?”

Two com­mon dis­eases brought on from high heat and sun ex­po­sure are white dru­pelet syn­drome and red dru­pelet disor­der, which dis­color the black­berry dru­pes — in­di­vid­ual parts of the berry — into that par­tic­u­lar shade. Some­times farm­ers will pick fine black­ber­ries in the fields and once they hit the mar­ket or be­come re­frig­er­ated, they’ll turn red or pink, McWhirt said.

“This looks bad and peo­ple don’t want to buy them,” she said.

Other is­sues McWhirt and her col­league Jackie Lee are in­ves­ti­gat­ing in­clude whether or not ro­ta­tional trel­lises will en­cour­age higher berry yields, and if the plants re­spond well to lower lev­els of fungi­cide and in­sec­ti­cide.

A pest also caus­ing U. S. black­berry dam­age is the Spot­ted Wing Drosophila. Orig­i­nally from Asia, the small fruit fly made its way into Amer­ica less than ten years ago and has since

caused sig­nif­i­cant dam­age to blue­berry, straw­berry, grape and black­berry crops.

With­out ad­e­quate con­trol mea­sures, the pests can re­sult in up to $ 500 mil­lion in an­nual losses in Western U. S. pro­duc­tion ar­eas, ac­cord­ing to a So­ci­ety of Chem­i­cal In­dus­try study.

The Spot­ted Wing Drosophila tend to hide in the dense canopies of black­berry plants. By ro­tat­ing berries on their side, McWhirt said that the canopies would be more ex­posed, al­low­ing eas­ier spray cov­er­age with less in­sec­ti­cide.

While the ro­ta­tional trel­lis sys­tem has the potential to re­duce plant and chem­i­cal costs, the sys­tem it­self is more costly — two to three times the price of a tra­di­tional sys­tem — and grow­ers may have to hire ad­di­tional la­bor for train­ing the black­ber­ries to the trel­lis.

The ro­ta­tional trel­lis sys­tem costs grow­ers an es­ti­mated $ 3,000-$ 5,000 an acre, ac­cord­ing to the Arkansas Di­vi­sion of Agri­cul­ture. McWhirt said part of her re­search would be look­ing into the eco­nomic vi­a­bil­ity of us­ing ro­ta­tional trel­lises over tra­di­tional ones.

Th­ese sys­tems were in­stalled at the Univer­sity of Arkansas Di­vi­sion of Agri­cul­ture’s Clarksvill­e sta­tion in May. Re­searchers are sched­uled to spend the first year get­ting the plants es­tab­lished, fol­lowed by about five years of data col­lec­tion.

An ef­fect ro­ta­tional trel­lises have had on black­berry pro­duc­tion na­tion­wide, is

that Arkansas black­berry va­ri­eties are able to grow in cooler cli­mates out­side of the state.

“Thirty- five years ago, I laughed at it,” said John R. Clark, di­rec­tor of the Univer­sity of Arkansas Sys­tem Di­vi­sion of Agri­cul­ture fruit breed­ing pro­gram.

He re­mem­bered stand­ing next to Fu­miomi Takeda, the U. S. De­part­ment of Agri­cul­ture re­searcher who re­fined the ro­ta­tional trel­lis years ago, think­ing the tech­nol­ogy would be too much has­sle for grow­ers — train­ing pick­ers, weav­ing the plants pre­cisely.

“It was just too much work. But when they started grow­ing Arkansas va­ri­eties in cooler cli­mates, I started pay­ing at­ten­tion,” Clark said.

Fresh black­berry pro­duc­tion has spiked in the North be­cause of the ro­ta­tional trel­lises, and south­ern grow­ers have taken to the tech­nol­ogy be­cause they swear “the qual­ity is bet­ter,” he said.

About 100 miles west of the Univer­sity of Arkansas lies an Ok­la­homa farm run by Bill Ja­cobs, 80, who’s been grow­ing thorn­less Arkansas black­ber­ries for nearly 20 years. In the last four years, he’s used ro­ta­tional trel­lises on about half of his black­berry acreage. He re­ceived a grant from the Ok­la­homa De­part­ment of Agri­cul­ture to record his own trel­lis observatio­ns.

“It has its pros and cons,” Ja­cobs said. “It’s pretty la­bor in­ten­sive.”

It takes about 60 hours per week for two of Ja­cobs’ work­ers to guide the black­ber­ries

through the trel­lis frame, he said.

At Ja­cobs’ U- pick oper­a­tion, he said ma­neu­ver­ing the berries to one side has given him more con­trol over his crop and made pick­ing faster and eas­ier for cus­tomers.

“There’s no hunt­ing. Ev­ery berry is hang­ing free and ex­posed,” Ja­cobs said.

His observatio­ns also matched McWhirt’s hy­poth­e­sis, that the ro­ta­tional trel­lis in­flu­enced the yield of berries with white or red dru­pelets and in­sect prob­lems.

“They’re com­pletely elim­i­nated,” Ja­cobs said.

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