Previcur Flex Fungicide - Propamocarb Hydrochloride 66.5% Systemic Fungicide for Pythium, Phytophthora & Downy Mildew

Previcur Flex Fungicide from Bayer CropScience is a systemic fungicide formulated with propamocarb hydrochloride at 66.5% (6.0 lb ai/gallon) - a Group 28 fungicide specifically targeted at Oomycete pathogens including Pythium root rot and seedling diseases, Phytophthora (late blight, pod rot, root rot), and downy mildew. It can be used as a solo product or in a tank-mix, where it combines its own systemic activity with the contact activity of a tank-mix partner (chlorothalonil, maneb, or mancozeb are specifically recommended for late/early blight control) for stronger combined disease protection. Previcur Flex is labeled for field use on cucurbits, tomato, pepper, and eggplant, leafy greens, lima beans, tuberous and corm vegetables (including potato), guava, and starfruit, plus greenhouse use on cucurbits, leaf lettuce, peppers, and tomato for Pythium and Phytophthora control during propagation.

Key Benefits

• Targeted Oomycete control - specifically effective against Pythium, Phytophthora, and downy mildew pathogens, filling a role that many broad-spectrum fungicides don't cover as well.
• Systemic + contact tank-mix strategy - pairing Previcur Flex with chlorothalonil, maneb, or mancozeb combines systemic and contact modes of action for stronger late blight and early blight control.
• Flexible application options - foliar spray, banded application, directed soil application, and chemigation (drip, transplant/setting water, or overhead) depending on crop and target disease.
• Greenhouse and field use - labeled for both field crop production and greenhouse propagation/production, covering the full lifecycle from seedling to harvest on several crops.
• Resistance-conscious chemistry - Group 28 mode of action; alternating with QoI (Group 11) fungicides is advised as part of a resistance management program.

Technical Information

• Active Ingredient: Propamocarb hydrochloride - 66.5% (6.0 lb ai/gallon)
• Formulation: Soluble liquid concentrate
• Fungicide Group: 28 (Carbamate)
• EPA Reg. No.: 264-678
• Re-Entry Interval (REI): 12 hours

Crops & Representative Rates

Rates and PHIs vary meaningfully by crop and target disease - always confirm the crop-specific rate and restriction before applying:

• Cucurbits (downy mildew, Pythium): 0.6–1.2 pt/A; PHI 2 days; max 6 pt/A/yr; max 2 applications/crop cycle, up to 4 crop cycles/acre/yr
• Tomato (late/early blight, tank-mix; Pythium): 0.7–1.5 pt/A; PHI 5 days; max 7.5 pt/A/yr
• Pepper & eggplant (Pythium): 1.2 pt/A; PHI 5 days; max 6 pt/A/yr
• Leafy greens (downy mildew, Pythium): 1.33–2.0 pt/A; PHI 2 days; max 8 pt/A/yr
• Lima beans (pod rot suppression, East of Rockies only): 1.2–2.0 pt/A; harvest restriction 12 hours; max 8 pt/A/yr
• Tuberous/corm vegetables incl. potato (late/early blight, tank-mix): 0.7–1.2 pt/A; PHI 14 days; max 6 pt/A/yr
• Guava & starfruit (Pythium root rot, soil-directed, not for CA without supplemental label): 2.0 pt/A; PHI 1 day; max 4 pt/A/yr; 30-day minimum interval
• Greenhouse (cucurbits, leaf lettuce, peppers, tomato): Rock wool/seed bed/drip/foliar use patterns with plant-density-based maximum rates - see label for the full greenhouse rate table

Overall annual maximum is capped per crop (ranging from 4 to 8 pints/acre/year depending on crop) - see label for the exact figure by crop. Do not exceed 2 applications per crop cycle, regardless of rate, and do not use on more than 4 crop cycles per acre per year on most field crops. Crop rotation: labeled crops may be replanted at any time; root and leafy vegetables require a 30-day wait; all other unlisted crops require a 120-day wait.

ALWAYS READ AND FOLLOW LABEL DIRECTIONS BEFORE USE.

Resources

Previcur Flex Specimen Label (PDF)
Safety Data Sheet (SDS PDF)