2 new premixes offer disease control

Sometime this year, growers will be introduced to two new premixes for disease control.

Palladium is a Syngenta Professional Products combination of the active ingredient in Medallion (fludioxinil) and cyprodinil (not currently labeled for any ornamental use).

Pageant is a BASF Corp. combination of the active ingredient in Insignia (pyraclostrobin) and boscalid (not currently labeled for any ornamental use).

These two products are by no means interchangeable but they can be especially effective rotational partners for a wide range of diseases.

A closer look at Palladium

Formulation: 62.5 percent WG (wettable granule) active ingredient combination.

Rates: The expected use rates are 2-8 ounces per 100 gallons.

Sites: The proposed use sites include greenhouse, outdoor container and field production of ornamentals.

Ingredients: Fludioxinil (Medallion – group 12) has been very effective against Alternaria, Botrytis, Cercospora, Cylindrocladium, Fusarium, Rhizoctonia and Sclerotinia.

Cyprodinil (group 9) is labeled for fruit trees and used to control Alternaria, Botrytis, Monilinia (related to Sclerotinia), powdery mildew (suppression) and Venturia.

Benefits: Combining fludioxinil and cyprodinil produces a broad-range fungicide as well as providing for resistance management in overlapping pathogen groups (especially Botrytis and Sclerotinia).

A closer look at Pageant

Formulation: 38 percent WG (wettable granule) active ingredient with a 2:1 ratio of boscalid to pyraclostrobin.

Rates: The expected use rates are primarily 12.5-18.5 ounces per 100 gallons although an 8-12.5 ounces per 100 gallons rate range is suggested for Alternaria.

Sites: Proposed use sites include ornamentals and flower bulbs grown in outdoor nurseries, residential and commercial landscapes, greenhouses, shade houses and interiorscapes.

Ingredients: Pyraclostrobin (Insignia – group 11) has been shown to be very effective against Alternaria, Cercospora, Cylindrocladium, downy mildew, Fusarium, Myrothecium, Phytophthora, powdery mildew, Rhizoctonia and Sclerotinia.

Boscalid (group 7) is labeled for certain vegetables and grapes and reported to be effective against Alternaria, Ascochyta (a form of anthracnose), Botrytis, Cercospora, powdery mildew, Rhizoctonia, rust and Sclerotinia. It is also labeled on turf for a variety of turf-specific diseases.

Benefits: As with Palladium, Pageant combines two active ingredients to greatly broaden the spectrum of activity while giving excellent resistance management strategies for Alternaria, Botrytis, powdery mildew, rust and Sclerotinia.

Use rates

Use rates for Palladium are lower than those for Pageant in part due to the lower amount of active ingredient in Pageant (38 percent) compared to Palladium (62.5 percent). The intervals of use are expected to be similar. I have been told by company technical representatives that rotating between these products in non-ornamental uses is common and very effective.

Chase Horticultural Research has been working with Palladium to a limited degree since the late 1990s and with Pageant since 2005. Here are summaries from some trials on each product. Proposed uses on the labels (as of December 2007) are listed in the last column. Be sure to check the labels as they are not final until the U.S. EPA says so.

Pageant and Palladium trials conducted by Chase Horticultural Research Inc.

Disease	Plants tested	Pageant results	Palladium results	Proposed label use
Alternaria leaf spot	Impatiens, pittosporum, zinnia	Very good to excellent at 4 or 8 oz. on a 7- to 14-day interval	Very good to excellent at 2, 4 or 8 oz. on a 7- to 14-day interval	Pageant, Palladium
Botrytis blight	Impatiens	Not tested	Very good at 6 oz. on a 10- to 14-day interval	Pageant, Palladium
Cercospora leaf spot	Myrtle	Very good at 12.5 oz. on a 14-day interval	Not tested	Pageant, Palladium
Colletotrichum leaf spot	Camellia	Excellent at 12.5 and 18.5 oz. on a 14-day interval	Not tested	Pageant
Colletotrichum leaf spot	Cyclamen	Not tested	Very good at 6 oz. on a 7-day interval	Pageant
Coniothyrium cane rot	Rose	Good to excellent at 12.5 oz. applied once	Not tested	Pageant
Cylindrocladium cutting rot	Myrtle	Good to excellent at 12.5 oz. applied once	Good at 6 oz. on a 14-day interval	Pageant, Palladium
Cylindrocladium root rot	Spathiphyllum	Excellent at 12.5 or 18.5 oz on a 14-day interval	Not tested	Pageant, Palladium
Fusarium chalk rot	Caladium	Some at 23 oz. applied once	Not tested	Pageant
Fusarium wilt	Cyclamen	Excellent at 12.5 and 18.5 oz. on a 14-day interval	None at 3 oz. on a 14-day interval	Pageant, Palladium
Fusarium leaf spot	Dracaena	Not tested	Very good at 3 oz. on a 7-day interval	Palladium
Myrothecium  petiole rot	Pansy	Some to excellent at 12 oz. on a 14- to 21-day interval	Good at 2, 4 or 6 oz. on a 14-day interval	Pageant, Palladium
Phyllosticta (Phoma) leaf spot	Euonymus	Excellent at 12.5 and 18.5 on a 14-day interval	Not tested	Pageant, Palladium
Powdery mildews	Gerbera, hydrangea, rose, scabiosa	Very good to excellent at 12.5 and 18.5 oz. on a 7- to 14-day interval	Not tested	Palladium
Rhizoctonia cutting rot and stem rot	Hydrangea, impatiens, poinsettia	Very good to excellent at 12.5 and 18.5 oz. applied once or twice	Good to excellent at 2-8 oz. on a 7- to 14-day interval	Pageant, Palladium
Rusts	Hypericum, solidago	Very good at 12.5 oz. on a 14-day interval	None at 4 oz. on a 7-day interval (hypericum)	Pageant
Sclerotinia	Petunia, primula	None at 18.5 oz. on a 10-day interval	Good to excellent at 2 or 4 oz. on a 7-day interval	Pageant, Palladium

Both Palladium and Pageant have been very safe in our trials and have not caused damage to any plant tested to date. There has been little visible residue with either product. Our trials have indicated especially good efficacy for Pageant on Alternaria leaf spot, anthracnose diseases caused by both Colletotrichum and Phyllosticta, Cylindrocladium cutting and root rot, Myrothecium petiole rot, powdery mildew and Rhizoctonia cutting rot. Palladium has shown very high efficacy on Alternaria leaf spot, Botrytis blight, Colletotrichum leaf spot, Rhizoctonia cutting rot and Sclerotinia blight.

Test differences

The reason for the numerous “not tested” comments is because some trials were under contract from the manufacturers while others were conducted for our own interest. It may not be as likely that a trial would be requested for Botrytis or Sclerotinia when in each product both active ingredients were shown to be effective on these two pathogens and their relatives. Thus, the exploration of lesser diseases like Cylindrocladium cutting rot and miscellaneous leaf spots was more likely. Also remember that each plant group has characteristic diseases critical for that group and perhaps of little interest in another type of crop.

Help in managing resistance

I started checking the two products in the same trial this past year when it was obvious they had significantly overlapping activity ranges and also would be launched for use on ornamentals in 2008. These two products will deliver four active ingredients to provide an excellent spectrum of activity while preventing fungicide resistance.

The chemical class groups for the two combinations are completely different. Palladium is 9 and 12 while Pageant is 7 and 11. This is an ideal opportunity to manage resistance while using two safe and highly effective new products.

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I still have questions about the best uses for these products and how they might differ. I hope to answer some of them in the coming year.

- A. R. Chase

A.R. Chase is president, Chase Horticultural Research Inc., (530) 620-1624; archase@chaseresearch.net; www.chasehorticulturalresearch.com.

- March 2008