Managing downy mildew events with RIDOMIL® Gold Plus and RIDOMIL® Gold MZ

Q: Primary infection: when spores move from the soil to the vine

To occur:Temperatures 8°C+ (don’t wait for 10°C)16 hours soil wetness (rainfall or irrigation)Rainfall in sufficient intensity to cause splash from the ground to foliage45°C hours of leaf wetness (equivalent to 2 hours at 23°C-hours), infection can still occur for 4-5 hours at 10°C for spores to infect a leaf or less at higher temperaturesOil spots may be seen 5-17 days later. Oil spots develop quicker in warm weather (18-27°C).

Q: Secondary infection: when downy mildew spreads from oil spots

Active oil spots need to be presentSpores develop on the underside of the leaf and cause new infection within the canopyUsually occurs in warm, humid nights (requires 4 hours darkness)

Q: What is the difference between RIDOMIL® Gold Plus, RIDOMIL® Gold MZ and a metalaxyl fungicide?

RIDOMIL® Gold Plus and RIDOMIL® Gold MZ provide double protection against downy mildew having metalaxyl-m co-formulated with a protectant:RIDOMIL® Gold Plus – 50 g/kg metalaxyl-m (Group 4) + 390 g/kg copper (Group M1)RIDOMIL® Gold MZ – 40 g/L metalaxyl-m (Group 4) + 640 g/kg mancozeb (Group M3), limited use in wine grapesRIDOMIL® Gold Plus and RIDOMIL® Gold MZ contain only the m-isomer of metalaxyl-M. Other metalaxyl formulations contain both isomers of metalaxyl (the M and P isomers), only the metalaxyl-M isomer is active against downy mildew e.g. 50 g/kg of metalaxyl-M is equivalent to 100 g/kg metalaxylCo-formulations provide an effective, convenient and safe option to control downy mildew.

Q: Is RIDOMIL® Gold Plus or RIDOMIL® Gold MZ an eradicant?

NO! Post-infection sprays work when applied as soon as possible after infection has occurred, BEFORE oil spots are seen.

Q: How many times can I use RIDOMIL® Gold Plus or RIDOMIL® Gold MZ per season?

Maximum 4 times per seasonDo not apply more than 2 consecutive applications

Downy mildew events: How to use RIDOMIL^® Gold Plus and RIDOMIL^® Gold MZ

Primary infection: when spores move from the soil to the vine

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To occur:

Temperatures 8°C+ (don’t wait for 10°C)
16 hours soil wetness (rainfall or irrigation)
Rainfall in sufficient intensity to cause splash from the ground to foliage
45°C hours of leaf wetness (equivalent to 2 hours at 23°C-hours), infection can still occur for 4-5 hours at 10°C for spores to infect a leaf or less at higher temperatures

Oil spots may be seen 5-17 days later. Oil spots develop quicker in warm weather (18-27°C).

Secondary infection: when downy mildew spreads from oil spots

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What is the difference between RIDOMIL® Gold Plus, RIDOMIL® Gold MZ and a metalaxyl fungicide?

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RIDOMIL^® Gold Plus and RIDOMIL^® Gold MZ provide double protection against downy mildew having metalaxyl-m co-formulated with a protectant:
- RIDOMIL^® Gold Plus – 50 g/kg metalaxyl-m (Group 4) + 390 g/kg copper (Group M1)
- RIDOMIL^® Gold MZ – 40 g/L metalaxyl-m (Group 4) + 640 g/kg mancozeb (Group M3), limited use in wine grapes
RIDOMIL^® Gold Plus and RIDOMIL^® Gold MZ contain only the m-isomer of metalaxyl-M. Other metalaxyl formulations contain both isomers of metalaxyl (the M and P isomers), only the metalaxyl-M isomer is active against downy mildew e.g. 50 g/kg of metalaxyl-M is equivalent to 100 g/kg metalaxyl
Co-formulations provide an effective, convenient and safe option to control downy mildew.

When do I apply a RIDOMIL® Gold Plus or RIDOMIL® Gold MZ?

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Apply these products early in the season when predictive disease modelling indicates an outbreak may be likely

When conditions favour disease development, apply TWO CONSECUTIVE SPRAYS of RIDOMIL^® Gold Plus or RIDOMIL^® Gold MZ as soon as conditions indicate the likelihood of disease development or as soon after an infection event as possible well before any oil spots are visible.