Although Merivon fungicide was registered about two years ago for pome and stone fruit, BASF didn't make a big marketing push because several key maximum residue levels, or MRLs, were missing.

Now with all of the major MRLs, including Japan and Codex, in place except for one, the Research Triangle Park, N.C.-based company plans a full-scale launch of the fungicide premix in time for the 2015 season, says Nick Schweizer, product manager.

The one missing MRL is Taiwan, and Schweizer says he expects that in early 2015.

Merivon is a premix of Xemium, the brand name for fluxapyroxad, and F500, a strobilurin that BASF markets as Cabrio or Headline. F500, also one part of the BASF premix Pristine, belongs to the Resistance Action Committee's Group 11.

Xemium is an SDHI, or succinate dehydrogenase inhibitor, fungicide and belongs to the FRAC Group 7. Boscalid, which BASF markets as Endura, also belongs to Group 7 and is the other part of the Pristine premix.

In apples, Merivon is strong against powdery mildew and scab, says Jennifer Holland, product manager. Because of its molecular structure, Xemium embeds itself in the leaf cuticle, allowing it to persist longer to provide better disease control, she says. It also is mobile in the plant xylem.

Strobulurins, on the other hand, are complementary, sticking to the leaf and not moving. 

In trials, Merivon has shown better activity against the target organisms than Pristine, Holland says.

Schweizer says the optimum application timing is full bloom—or about the same timing as Pristine.

In stone fruit, including cherries, the premix is active against brown rot, scab, blossom blight, gray mold, powdery mildew and ripe fruit mold, to name a few. Again, he says, full bloom is optimum timing.

Merivon received California registration for use on almonds mid-way through the 2014 season, so a limited amount was put out mid-season for alternaria, Holland says.

2015 will be the first full season for the product in California almonds, where it is effective as a full-bloom spray against shothole and blossom blight, among other diseases.

In addition to providing strong disease control against the target fungi, Holland says company researchers have noticed that Merivon also promotes overall plant health in the dozen or so crops tested.

“Almonds, tomatoes, corn and about a dozen other crops—annual and perennial—Merivon is having an overall impact on the health of the crop,” Holland says.

In greenhouse trials with potted almond trees, plants treated with the fungicide had larger root masses than those treated with a competitor's product or not treated.

Other trials showed that plants sprayed with Merivon handled heat and water stress better than those treated with other products.

Initial results of field trials conducted in the Northeast have shown that the fungicide may help promote apple fruit color, size and Brix because it helps improve leaf photosynthesis, she says.

The next wave of trials will be conducted in 2015 in the Pacific Northwest, Holland says.