By Clint Thompson
The current prolonged dry period covering most of Florida is impacting North Florida watermelons. While producers prefer drier weather, they need to ensure their crop is receiving adequate moisture.
Growers need to be more diligent in making sure fields are saturated with multiple irrigation events per day while the drought persists, says Bob Hochmuth, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) regional specialized Extension agent in Live Oak, Florida.
Most growers have only been utilizing one irrigation event per day in recent weeks. Some have increased the length of those events from two to three or four hours. Hochmuth stresses that producers should avoid this strategy. Instead of one 3-to-4-hour irrigation event, growers need to utilize two shorter events of 1.5 hours each.
“The soil can only hold so much water. After you have applied, let’s say one hour of water, that usually irrigates the top 12 inches of the soil. In the case of watermelon, 85% of the root zone is in that top 12 inches. When we start to irrigate down very much lower than that, we eventually get to the point at probably 18 inches where there’s less than 5% of the root system,” Hochmuth said. “After you get past that first hour or hour and a half, two hours, depending on the flow rate of the drip tape, at some point in time you move water down past the effected root zone. In other words, you have filled the sponge and everything else is running out of the bottom. You would be better to fill the sponge to the bottom of the sponge, let the root system pick it up and then refill the sponge later the same day.”
According to the U.S. Drought Monitor, the extreme drought that was present in southern Florida has moved up the east coast. A severe drought continues to be observed throughout most of the state, starting as far north as Dixie and Gilchrist counties and stretching as far south as Collier County. A moderate drought remains in Northeast Florida and most of southern Florida.
“It’s very dry, light scattered showers (Monday and Tuesday), nothing very widespread and nothing very significant up to this point,” Hochmuth said. “The further south you go from the Georgia-Florida line, the drier it gets.”