The relatively mild winter conditions over the last two decades have led to a resurgence of interest in cold-hardy citrus in Florida. Growers were looking for a low-seeded citrus variety that was sweet, easy to peel and had moderate cold tolerance. In 2009, the first Florida nurseries were licensed to grow Tango, a low-seeded (less than five seeds per fruit when grown in a mixed block) Murcott.
Although Tango was not specifically brought to Florida for cold hardiness, it does appear well suited for colder areas. Tango appeared to be a better option for growers who were interested in growing low-seeded mandarins that could be grown in close proximity to other citrus varieties without risking an increase in seed count. By early 2010, growers were able to request commercial licenses to produce Tango.
Peter Chaires, executive director of New Varieties Development & Management Corp., recently hosted a meeting of nurseries and growers to discuss their experiences with Tango. Tim Williams, a breeder at University of California, Riverside (UCR), also participated in the call. Tango is a UCR variety, so he had extensive knowledge and experience he was able to share with the group.
“With Tango, we continue to see the trees do reasonably well,” says Chaires.
According to Chaires, Tango trees perform better than average with huanglongbing (HLB). The trees show HLB symptoms but keep cropping.
Other growers noted the excellent flavor the variety produces and its beautiful internal color.
Pete Anderson, University of Florida emeritus professor, reported that the 10-year-old Tango trees budded on Swingle at the North Florida Research and Education Center in Quincy average about 200 pounds per tree with the fruit weighing approximately 120 grams.
The fruit typically mature in December, but they tend to have better color if they’re held on the tree into January.
Although the internal color appears to be great for Tango, the external color has proven to be an issue over the past few years.
“Peel color has been a considerable challenge,” says Chaires. As growers shared their experiences with Tango, this seemed to be the No. 1 challenge across the board.
Currently, Tango cannot be de-greened with ethylene gas, at least not with current methods. The inability to de-green has forced growers to pick for color and let the grading line ensure that a high-quality product goes in the carton.
Producers have attempted to de-green fruit by holding it in coolers until desired color was achieved. However, many growers didn’t experience any success with this method.
Overall, Tango shows a lot of promise for the border counties.
“We have seen excellent fruit quality and color in traditional production areas. The challenge has been consistent color,” says Chaires. “Temperature definitely plays a role, but there are factors impacting color that we don’t yet understand. We have seen excellent color in Hendry, St. Lucie, Orange, etc. But one year the color is excellent, and the next not as much. We need to understand why. Rootstock may have an impact.”
Experts are in close communication with growers in Queensland for that reason, says Chaires. “They have a very similar climate to Florida and are doing some trial plantings of Tango,” he says. “They don’t have the HLB factor yet, so not all of their gleanings are applicable here, but they are the production area closest in characteristics to Florida.”
Chaires also notes the lower brix seen in some fruit that was not seen years ago. “This isn’t true everywhere — just sporadically,” he says. Experts are unsure of what is driving this. Early plantings were consistently 13-14 brix. Most of those were on Cleo. Now some trees are struggling to get out of the 9s. Chaires believes this could be rootstock driven, but there are no conclusive answers at this time.
Ashley Robinson, a communications intern for AgNet Media, wrote this article.