Millennium Block Resurrected for HLB Research

johnny ferrarezi

An approximately 35-acre research plot that fell victim to citrus canker years ago will soon become a new research site helping growers pick trees that fare best with HLB. The plot at the Indian River Research and Education Center (IRREC) in Fort Pierce will keep its former name, the Millennium Block.

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researcher Rhuanito (Johnny) Ferrarezi updated plans for the site at the Indian River Citrus League’s annual meeting on Nov. 17.

“The Millennium Block is a great initiative that was put together about a year ago in order to assess the best grapefruit varieties we have available from the UF/IFAS and the USDA (U.S. Department of Agriculture) programs,” Ferrarezi says. Another objective of the site is “to test the UFR rootstocks in grapefruit, navel orange and mandarins here at the Indian River in order to generate local data to help growers to select the new varieties they will be planting in the future,” Ferrarezi adds. “Those varieties are the most (HLB) tolerant ones we have identified … and they are all readily available.” So growers can plant them soon “if we identify some good combinations,” the researcher says.

The Millennium Block research will be focused on varieties that work well for the fresh-fruit market.

Ferrarezi says he hopes that “we’ll be able to actually reverse this strong decline we’ve been seeing in grapefruit production.” Florida now produces a small fraction of the grapefruit it grew before the devastating citrus disease HLB was discovered in the state in 2005. The vast majority of Florida grapefruit is grown in the Indian River area.

Research in the Millennium Block will focus on grapefruit yield, fruit quality and fruit drop. The amount of fruit that drops before it can be harvested has increased dramatically because of HLB. “We want to maintain fruit on the trees,” Ferrarezi says. “We want to basically quantify how good those varieties are under high HLB pressure. And primarily we want to identify all the horticultural aspects of those varieties here at the (Indian) River. They’re commercial varieties, but we have few data available at the moment that would allow growers to choose those varieties right now.”

Ferrarezi reports that trees have been ordered for the block and should be available for planting beginning in the fall of 2018. Planting will start on 24 acres, but there is room to expand plantings to 35 acres. The project will last at least six years. Researchers need three years to get trees into production, and then there will be a solid three years of yield data, Ferrarezi says.

The Millennium Block is being resurrected on a varieties research site of the same name that began at the IRREC in 2000. That research “basically got pushed back after canker eradication,” Ferrarezi says. He tried to change the block’s name with the new research project, “but everybody said, ‘Yes, we know what you’re talking about, the Millennium Block.’ So we are sticking to that name because it’s something that is locally known. Of course we have different objectives, but I think it’s a good name.”

Ferrarezi says the Millennium Block project is a cooperative effort among staff and breeders at the IRREC, Citrus Research and Education Center breeders and USDA breeders. There has also been strong support from Indian River growers during the planning stages.

“We are really glad that we are bringing large grapefruit plantings back to this center after … 12 years,” Ferrarezi says.

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Ernie Neff

Senior Correspondent at Large