By Frank Giles
Blackberries have been produced in Florida for some time, but new efforts have been made to learn more about the crop to grow production and markets in the state. Blackberries have been proven to be a popular item at U-pick operations. For farmers who grow U-pick strawberries and blueberries, blackberries offer a way to extend the picking season.
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have been studying blackberries and have educational resources available to growers interested in trying the crop. Recently, a blackberry field day was hosted by UF/IFAS at the Gulf Coast Research and Education Center (GCREC). Among the attendees were Joe and Becky Myers, who own and operate Acres of Grace Family Farms in Howey-in-the-Hills, Florida. The father-daughter team grow organic blackberries and say the crop is a hit with their customers.
In addition to blackberries, the farm provides organic peaches, citrus, herbs, vegetables and eggs. The U-pick opened for the first time in April 2020 as the COVID-19 pandemic spread.
“It was scary opening right as the pandemic started,” says Becky. “We had no idea what to do. We had fruit on plants that was ready and falling off. So, we went ahead and opened and were overwhelmed with how many people came to the farm. Everyone wanted to be outside and get out of the house. I think it really helped people deal with the pandemic.”
“Now we have families that have come here every year since we opened,” says Joe. “Some drive from as far away as two hours. It is a great spot for families to come for the U-pick, and there’s a lot of space for kids to play. Some families will spend hours on the farm.”
Becky uses Facebook, Instagram and Google to market the farm. She says a website is also under development to help build the farm’s marketing program.
One of the biggest challenges of growing blackberries in Florida is finding the right varieties. Many of the varieties currently available require too many chill hours. These cultivars were bred in states with cooler climates than Florida. The University of Arkansas has one of the largest blackberry programs in the country.
Zhanao Deng, a UF/IFAS professor of environmental horticulture, has been evaluating the Arkansas varieties at GCREC. During the field day, he led a tour of the variety trials. He reiterated the challenge presented by chilling requirements of current cultivars, but said there are some that have performed well, especially in U-pick or direct-to-consumer situations. Finding varieties for commercial shipping remains challenging.
The best overall, consistent-performing variety to date is Prime-Ark Freedom. It is the world’s first commercial thornless primocane-fruiting cultivar, released by the University of Arkansas in 2013. Plants are vigorous and produce strong, thick canes. Fruits ripen in late April to early June. The berries are very large, elongated and attractive.
“So far, Prime-Ark Freedom has had the highest yield in our trial,” Deng said during the field day. “We have produced about 7.7 pounds of berries per plant. This variety is a little early. This might not be ideal for commercial growers because it overlaps some with the window of imports from Mexico. This variety also has reverse coloring (turns back red) after harvest, so it is not going to be good for the shipping market, but it will be good for local, direct sales.”
Prime-Ark Freedom is the variety planted on Acres of Grace Family Farms. It produces a good crop and is popular with customers.
“I like the size of the fruit, and I like the taste and texture. They are very sweet and not very seedy,” Becky says. “And this variety has won over converts to blackberries. People have come to the farm and tried them and said they didn’t even like blackberries, but they like these. Another very important thing with this variety is they are thornless. I can’t image doing a U-pick without thornless varieties.”
Becky says she plans to stick with the Prime-Ark Freedom variety but is considering the Big Daddy variety.
“They are the same size fruit as Prime-Ark Freedom and slightly less sweet,” she says. “For things like jellies and pies where you are adding a lot of sugar, a slightly less sweet variety would be attractive to those customers.”
Deng has established a breeding program at GCREC to develop varieties more suited for Florida conditions. Classic breeding techniques have been used to select desirable traits for Florida. About 15 lines of cultivars are currently under evaluation.
B1 is a UF/IFAS variety that is showing promise. It also has potential for the commercial shipping market due to its firmer fruit.
“Based on our trials with B1 over the past two years, the berries are firm and large, and the Brix is good. It is sweeter than Prime-Ark Freedom,” Deng said during the field day. “The yield is not as high as Prime-Ark Freedom, but with the firm, higher marketable fruit and good Brix, we believe it has potential. It has very good plant vigor and growth habit. It also is a little later than Prime-Ark Freedom, which is a positive for the commercial market.”
TRICKING MOTHER NATURE
Current blackberry cultivars require 300 to 900 chill hours below 45 degrees. When plants do not receive adequate chill hours, budbreak becomes poor and erratic. In Central Florida, chill hours average only about 250 hours.
To counter the effects of low chilling hours in Florida, Shinsuke Agehara, UF/IFAS assistant professor of horticulture, has been studying chemical applications to induce budbreak in blackberries. He presented his research during the GCREC field day. Agehara has had some success with the use of gibberellic acid in other crops, but it appears the hormone will not be as effective in blackberries. But Agehara has found that applications of urea have induced budbreak in blackberries. Urea acts as a defoliant of the plants.
“For any area that has less than 500 chill hours per year, we recommend applications of urea,” Agehara said. “Those applications should be made from mid-February to early March, which is right before natural budbreak timing in blackberries.”
PROVIDING POSITIVE SPACE
The Myers believe that keeping their space green and growing food for their own family and others is especially important these days. Joe says he put a lot of income toward the farm and property to farmstead there. His children all have plots to build on when they choose to.
“We are not going to make a fortune doing this, but it is a blessing to our family and extended family,” Joe says. “We have enough to support and feed our family, but also have created a place for the local community to experience and enjoy.”