Makhteshim-Agan launched Morph in UK

Potato growers have a valuable new spray that will assist them to fight potato blight. The recent launch of Morph (dimethomorph), from Makhteshim-Agan (MAUK), will help them control all blight strains, including those that are phenylamide-resistant and the aggressive 13_A2 type.

"This strain of blight is more aggressive and less forgiving, so growers need to start early and keep intervals tight," advises SAC blight specialist Dr Ruairidh Bain.

He encourages growers to move away from pre-planned programmes. "Bring a range of products into your spray store, then keep an eye on risk periods and incidents of blight in your area. Use this information to match your programme to the risk, building in more robust elements as conditions dictate."

The introduction of Morph makes the curative active ingredient dimethomorph, previously only obtainable as a co‐formulated product, available on its own, although it must be used in mixes. This allows growers more flexibility when deciding what to spray.

"The key strength of dimethomorph is its persistence, more than twice that of cymoxanil," notes Dr Bain, "although cymoxanil is rated ++ for curative activity whereas dimethomorph is rated +."

Morph has been formulated as a low-dose liquid, adds MAUK’s Stuart Hill. At the recommended dose of just 0.3l/ha, it is easier to handle than the previous wettable powder co-formulations, usually applied at 2kg/ha. "Morph is locally systemic helping to protect new growth early in the season and has kick-back activity on mycelium."

Mr Hill recommends it is mixed with 0.3l/ha of Volley (fluazinam). "This is a multi-site protectant fungicide with good activity on tuber blight that is also effective against zoospores. It complements well the persistence and curative activity of Morph."