Downy mildew disease remains the most important threat to North Florida watermelons, a couple of weeks into harvest season. That’s the assessment made by Bob Hochmuth, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Regional Specialized Extension agent in Live Oak, Florida. The disease has not “blown up” this year, and Hochmuth attributes that to growers being proactive in their disease management strategies.
“I also believe most farmers across the region have done an excellent job getting ahead of this disease with sprays such as Ranman or Orondis Ultra. Both also have 0-day pre-harvest interval,” Hochmuth wrote in his weekly email. “In rare instances where sprays had not been initiated prior to last week, downy infections were easy to find.”
Producers should also be wary that if they do not observe spots of infection and have just used Orondis Ultra, their crop should be protected for 10 to 14 days.
Powdery Mildew Sprays
Powdery mildew reports have also been very low in recent weeks, though UF/IFAS Extension is occasionally finding infection in some watermelon plants. Scouting remains essential for growers moving forward.
“Remember, you can always add a broad-spectrum material like mancozeb if it will be five or more days to harvest from the spray,” Hochmuth added. “A good scouting program now and until the end of the season may save several unnecessary and expensive sprays.”
Rindworm Sprays
Hochmuth added that farmers should continue a preventative spray material for rindworms. Intrepid, Troubadour, Coragen eVo or generic versions are good options.