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New SDHI fungicide hits the spot in potatoes

Potatoes
20.12.2018
New chemistry delivers step change in early blight control

Last season saw the introduction of MIRAVIS®, a new SDHI preventative fungicide from Syngenta containing ADEPIDYN® approved for the control of early blight (target spot) in potatoes. 

New Zealand was one of the first countries in the world to register MIRAVIS in potatoes.  Feedback from growers (and agronomists) on the performance of MIRAVIS last season has been extremely positive, with reports of crops looking cleaner and greener where MIRAVIS was applied.

MIRAVIS belongs to a new SDHI chemical group (N-methoxy-(phenyl-ethyl)-pyrazole-carboxamide), with superior intrinsic preventative activity against early blight, and exceptional rainfastness due to its strong lipophilic (wax binding) properties.

Once applied, MIRAVIS quickly forms a reservoir in the leaf wax, protected from wash-off by rainfall or irrigation. It is gradually taken up by the plant, providing long lasting disease control and extended green leaf area, leading to increased marketable yields.

When used for early blight control in potatoes, MIRAVIS can either be applied alone or in mixture, although mixtures are recommended for resistance management. If used alone it must be applied in alternation with fungicides from a different activity group. If applied in mixture, no more than two should be applied in a row.

Application timing is critical for early blight control, and this means spraying preventatively prior to disease symptoms showing up in the crop. A preventative application of MIRAVIS is recommended at, or just prior to, row-closure for improved coverage on lower leaves. A repeat application can be made 7 to 14 days later if required, if the previous application was applied in mixture.

The best mixing partner for MIRAVIS will depend on disease pressure and variatal susceptibility to early blight. The addition of SCRORE is recommended in high pressure situations on susceptible varieties, offering some curative activity on early stage infection. The addition of mancoceb is suitable on more tolerant varieties in low disease pressure and preventative situations.

Syngenta recommends applying MIRAVIS using angled DEFY 3D nozzles in a minimum of 200 litres of water per hectare in an open canopy, increasing to 300 litres of water in a thick canopy post row-closure.  With a 38 degree spray angle, DEFY 3D nozzles should be fitted to the spray boom alternating forwards and backwards along the boom, improving coverage in the crop canopy for improved disease control.

A maximum of three sprays of MIRAVIS can be made to potatoes per season, with a withholding period of 14 days.

Click here to download the Technote on MIRAVIS in potatoes, including application rates and trial results.