By Frank Giles
The coldest temperatures in years predicted for Florida over the weekend has fruit and vegetable growers worried and preparing to protect their crops. Temperatures in the 20s and 30s are expected deep into the peninsula of Florida. And the freezing weather could persist for up to four hours or more.
Gene McAvoy, associate director for stakeholder relations at the University of Florida Institute of Food and Agricultural Sciences Southwest Florida Research Center in Immokalee has been tracking the situation and advising growers.
Vegetables
“Warm-season vegetables like green beans, sweet corn, tomatoes, peppers, potatoes, squash, herbs and watermelons are at most risk,” McAvoy says. “We have a lot of young watermelons out there.”
According to McAvoy, running water is the first line of defense against the cold. Water comes out of the ground at 55 degrees Fahrenheit and helps produce a microclimate in the fields. Wetting soil allows it to absorb some heat during sunny weather, which is then released at night again creating a microclimate.
“Growers also are covering some crops if they have covers from years past,” he says. “Freeze cloth is impossible to find right now as the same material is being used in masks for COVID-19, so there is none to be purchased. Growers can also cover young plants with paper and soil, and some use Styrofoam cups or take-out containers. They can apply different protectant chemicals like Vapor Gard, which may provide a degree or two of protection but also reduces desiccation of foliage by cold winds. Some sweet corn and green bean growers may fly helicopters to mix warmer air from aloft with cooler surface air.”
Citrus
Mongi Zekri, a citrus Extension agent based in LaBelle, Florida, says citrus growers are keeping a wary eye on the forecast, too.
“It may get below 29 degrees Fahrenheit in certain areas of Southwest Florida, which is cold enough to damage fruit,” Zekri says. “Citrus growers will turn to microsprinkler irrigation to freeze protect. Turn on the water early at 36 degrees Fahrenheit before the air temperature reaches freezing. Remember, in cold pockets, the ground surface can be colder than the air temperature reading in a thermometer shelter. Growers are recommended to use the information at the (FAWN website) to determine when it would be safe to turn on and off their microsprinkler irrigation system.”
To provide additional cold protection in bedded citrus groves, Zekri suggests water should be pumped high in the ditches the day before and during the time of freezing weather.
McAvoy adds growers are hoping the wind lays down during the freeze. Windy conditions can reduce the effectiveness of running water to protect crops. “Praying for the best; this promises to be the coldest weather in around 10 years,” he says.
