Powdery mildew is a key disease that is always targeted by New Zealand viticulturists in their wine grape fungicide programme. Get it wrong, and the foliage and berries in your vineyard can take on powdery mildew’s characteristic furry, somewhat dirty, appearance. But get it right with a robust mix of fungicides with different modes of action (MoAs), and your grapes stay clean and glossy until harvest.
Chemical rotation is essential to managing the physical disease as well the risk of local powdery mildew populations developing resistance to any MoAs in your programme.
“BASF has four fungicides from five different MoA groups to help control powdery mildew,” says Tim Herman, Senior Technical Services Specialist - Crop Protection for BASF New Zealand Ltd.
“The sulphur-based formulation Kumulus® DF (MoA group M02) is a veteran of many protectant programmes used to prevent powdery mildew from early in the season right through to harvest. Kumulus can be used as a tank-mix partner for other powdery mildew fungicides that only act at a single site within the target pathogen, as required by Sustainable Wines NZ (SWNZ). It is also BioGro registered.”
Tim says: “Belanty® is the first of a new generation of DMI fungicides with outstanding activity against powdery mildew. Applied when grapes are pea-size or pre-bunch closure, it gives all-round protection of grape and rachis before the bunches close up.”
Belanty is from MoA group 3 with the active ingredient mefentrifluconazole. It’s a single-site fungicide that should be tank-mixed with Kumulus. Note: Two applications of Belanty are permitted on the label, however SWNZ allows just one DMI application per season.
With the active metrafenone, Vivando® (MoA group 50) is another single-site fungicide that can be tank-mixed with Kumulus. Its vapour action increases its ability to treat a greater surface area.
“While there is flexibility as to where the two permitted Vivando applications are made, its short pre-harvest interval (see table) means it is best suited late in the programme,” Tim recommends.
Pristine® (boscalid + pyraclostrobin, MoA groups 7 and 11) is a co-formulation of a SDHI and strobilurin fungicide. It has activity against powdery mildew, Botrytis and downy mildew. Note: Resistance in powdery mildew pathogens to a strobilurin fungicide has been reported (Beresford et al 2016) so there is likely to be resistance to pyraclostrobin. The Pristine label allows for two applications per season. They also help control downy mildew, which has become a greater problem during recent wet summer conditions.
Tim adds: “As more viticulturists counter increased risk of downy mildew, this is where Delan® WG (dithianon, MoA group M9) comes to the fore, particularly with the deregistration of mancozeb in the European market. Delan is also used to control black spot (anthracnose) in warmer, damper grape-growing regions. Another option for downy mildew control is Polyram® DF (metiram, MoA group M03).”
NZ Wine Growers Vineyard Spray Schedule 2023/24
Pre-harvest Intervals
| Product | For nil residues in wine | For maximum residue limit compliance |
| Belanty | 65 days (pre-bunch closure) | 65 days (pre-bunch closure) |
| Delan WG | EL-18 (pre cap-fall) | 21 days, except Canada-OLCB: 28 days |
| Kumulus DF | 1 day | 1 day |
| Polyram DF | EL-18 (pre cap-fall) | 28 days except Canada: 14 days; Canada-OLCB and EU: EL-18 (pre cap-fall) |
| Pristine | EL-18 (pre cap-fall) | 28 days, except Canada-OLCB and Taiwan: EL-25 (80% cap-fall) |
| Vivando | 42 days | 42 days |
“With many excellent options to mix and match, please bear in mind that it’s vital to follow label directions and check the compatibility of potential tank-mix partners. The right combinations can achieve effective control of powdery mildew cost-effectively, and avoid the sort of fungicide over-use that might accelerate the progress of resistance.”
Find out more about any of these BASF products by talking with your local Fruitfed Supplies Technical Horticultural Representative.
ACVM registration numbers: Belanty® #P009798, Delan® #P003507, Kumulus® DF #P003493, Polyram® #P002062, Pristine® #P007595, Vivando® #P007973. Read registered label before use.