University of Florida/IFAS Extension agents in the Suwanee Valley area are confident downy mildew disease is in the region’s watermelon crop. Producers need to spray for this disease, also known as “wildfire.”
Spray programs especially need to be initiated in the southern parts of the Suwannee Valley region, including in Levy and Gilchrist counties, where the first reports of the disease were observed. However, northern counties like Suwannee, Lafayette, Columbia, Madison and Union need to be on alert. The disease is expected to move northward.
Growers need to contact their Extension agent if they see areas of their field where the plants look blighted or have dried up leaves sticking up in the middle part of the canopy. The leaves will become crispy if the disease is more advanced.
For fields where downy mildew has been confirmed, apply Orondis Ultra or Zampro this week and Ranman next week. Where downy mildew has not yet been detected, start with Ranman this week and follow with Orondis Ultra or Zampro.
Also, be cautious about spraying this week during what’s expected to be high temperatures. Likelihood of burn is greater when temperatures are high and 2-to-3 materials are tank mixed.