3 March 2000

New triazole – all-round control claim

METCONAZOLE, the new triazole from Cyanamid launched last week has the broadest crop spectrum and best all round disease control, the company claims.

Sold as Caramba, a novel soluble concentrate formulation means it is rainfast in 15 minutes, considerably faster than other triazoles.

"Even rain two days later rain causes quite a big loss of efficacy with epoxiconazole or tebuconazole," notes fungicide researcher Ewald Sieverding.

Movement of metconazole within the plant is slow so it is very crop safe, and it is more persistent than tebuconazole (as in Folicur) and epoxiconazole (as in Opus). Curative activity or "Kick-back" at full-rate is comparable with epoxiconazole on septoria. (see table)

"At low-rates epoxiconazole has the edge on curative activity but in practice, mixed with a strobilurin, you wont see a difference in performance between the two," says marketing manager Eric Gussin. Control of rusts is comparable with tebuconazole, he adds.

As an earspray Caramba is claimed to be more effective than tebuconazole on both fusarium and michrodochium. "It decreases the mycotoxin content in grains better than any other fungicide, and improves grain quality," says Dr Sieverding.

Despite such advantages as an ear spray, Mr Gussin sees its main role as a strobilurin partner for T1 and T2 sprays. "Growers should spend most at the beginning of the program to make sure they get it right to start with. Then you might get away with a cheaper T3," he suggests.

Price will be pitched to compete with Folicur. "The target price suggested is £18/litre, so for a 5-litre pack that is £90." Full recommended rate is 1.5 litres/ha delivering 90g/ha of active ingredient, the lowest amount of chemical/ha of all the triazoles.

On barley, metconazole is claimed to set a new standard over flusilazole (as in Sanction). Mildew and rust control is as good as tebuconazole and net blotch control shows a marked improvement over epoxiconazole, the next best triazole for the disease, says fungicide marketing manager Mike Barrett.

For rhynchosphorium 1.0 litre/ha of Caramba plus 0.6 litre/ha of Amistar (azoxystrobin) has the edge on 0.75 litres/ha of Landmark (epoxiconazole + kresoxim-methyl), he adds.

Work on oilseed rape shows phoma control is a step up on tebuconazole or difenconazole (as in Plover) and Caramba has an edge on tebuconzole for light leaf spot control. Alternaria and sclerotinia are also controlled and ADAS trials show a marked reduction in lodging following a stem extension application of 0.8 1itres/ha.

Morleys Doug Stevens sees metconazoles edge on rhynchosporium as an advantage, especially in the winter crop. "On spring barley the rhynchosporium is slower to get going. Growers will want to tank-mix it for the best possible cover, probably with Amistar," he suggests. On wheat it is an alternative to Folicur as an earwash, but not as good as Opus on septoria. "A lot is going to come down to the price, like the Novartis strobilurin."

Kick-back comparison


Triazole Day degrees

Epoxiconazole 245

Metconazole 240

Cyproconazole 230

Propicaonzole 200

*Day degrees = curative activity on septoria tritici

Source: Cyanamid

CARAMBACLAIMS

&#8226 Record rainfastness.

&#8226 Best spectrum of control.

&#8226 Use on wheat, barley and OSR.

&#8226 Yield response equals epoxiconazole.