Previcur® Flex Fungicide is a systemic fungicide solution formulated for the preventative and curative control of key oomycete diseases in a range of commercial vegetable and greenhouse crops. It is characterized by its rapid uptake, acropetal systemic movement, and unique chemistry within Fungicide Resistance Action Committee (FRAC) Group 28, which provides a critical mode of action for resistance management strategies. The product is registered for use in all continental U.S. states and Hawaii.
Chemical Composition and Formulation
The active ingredient is propamocarb hydrochloride, formulated as a soluble concentrate (SL) at a concentration of 66.5%. The remaining components are inert formulants.
Mode of Action
Propamocarb hydrochloride is a carbamate fungicide with systemic properties. It is absorbed rapidly by plant tissues—including roots, stems, and leaves—and translocates upward through the xylem (acropetal movement). This systemic activity provides protection to new growth following application. The compound interferes with cell membrane synthesis and composition in target pathogens, specifically inhibiting mycelial growth, sporulation, and germination of sporangia. Its classification in FRAC Group 28 denotes a unique site of action among fungicides, making it a vital rotational partner to mitigate resistance development.
Target Pathogens and Registered Crops
Previcur Flex is specifically labeled for the control of diseases caused by oomycete pathogens, including downy mildew (e.g., Pseudoperonospora cubensis), late blight (Phytophthora infestans), and diseases caused by Pythium spp.
Primary Registered Crops Include:
Application Specifications and Protocol
The product is labeled for application as a soil drench, through drip irrigation (chemigation), or as a foliar spray. Specific use rates (typically ranging from 0.8 to 3.0 pints per acre) are dependent on crop, disease pressure, and application method and must be obtained from the official product label.
Mixing and Application Guidelines:
-
Tank Mix Compatibility: Previcur Flex is physically compatible with most common fungicides, insecticides, and foliar nutrients. A jar compatibility test is required prior to mixing with any unlisted tank-mix partner. The standard mixing order is to add wettable powders or water-dispersible granules to the spray tank first, followed by the required quantity of Previcur Flex, and then any emulsifiable concentrates or liquid additives last.
-
Application Timing: For optimal efficacy, applications should begin preventatively or at the very first sign of disease under conditions conducive to infection.
-
Agitation: Maintain constant agitation in the spray tank and use the spray mixture immediately. Do not allow the mixture to stand overnight.
Efficacy and Performance Data
Field performance demonstrates strong preventative and curative activity against the target oomycete diseases. The systemic activity provides extended protection of new growth. Its unique FRAC Group 28 chemistry provides high efficacy and makes it a cornerstone for fungicide resistance management programs in susceptible crops, particularly where other chemical groups (e.g., phenylamides, QoIs) may have developed reduced sensitivity.
Regulatory and Safety Profile
-
EPA Registration Number: 0000264-00678
-
Personal Protective Equipment (PPE): Applicators and handlers must wear a long-sleeved shirt, long pants, chemical-resistant gloves constructed of barrier laminate, butyl rubber (≥14 mils), nitrile rubber (≥14 mils), neoprene rubber (≥14 mils), natural rubber (≥14 mils), polyethylene, polyvinyl chloride (≥14 mils), or Viton (≥14 mils), and shoes plus socks.
-
Restricted Entry Interval (REI): 12 hours for all crops except greenhouse-grown transplants, which have a 24-hour REI.
-
Pre-Harvest Interval (PHI): PHIs vary by crop (e.g., 7 days for tomatoes, 14 days for cucurbits) and must be strictly adhered to as stated on the label.
Storage and Stability
Store in a cool, dry, well-ventilated area away from heat and direct sunlight. Keep container tightly closed. Do not contaminate water sources, food, or feed through storage or disposal.
