NDSU Crop and Pest Report
Plant Pathology


ISSUE 1  May 1, 2003

 

FUNGICIDE UPDATE FOR BROADLEAF CROPS, 2003

Several fungicide additions and changes for broadleaf crops in North Dakota have been made for the 2003 growing season, and are listed below. Refer to fungicide labels for specific information and directions before making applications.

Headline (pyraclostrobin)

Headline is a new foliar fungicide from BASF that is labeled for use on chickpea, dry bean, field pea, potato, and sugarbeet. It can be applied at 5.5 to 8 fl. oz./acre for control of anthracnose, Ascochyta blight, powdery mildew, and rust for chickpea, dry bean, and field pea. It can be applied at 6 to 9 or 6 to 12 fl. oz./acre for control of early blight and late blight of potato, respectively. For sugarbeet, Headline can be applied at 9 to 12 fl. oz./acre for control of Cercospora leaf spot and powdery mildew. Headline belongs to the strobilurin (QoI) fungicide class, in which plant pathogens have the potential to develop resistance to. To reduce the potential of developing fungicide resistance, alternate Headline with a fungicide from a different class, and limit the application number of strobilurin fungicides in a growing season.

Protege (azoxystrobin)

Protege is a new seed treatment fungicide from Syngenta that is labeled for use on chickpea, dry bean, field pea, lentil, and sunflower. It can be applied at 0.153 to 0.765 fl. oz./cwt to seed of chickpea, dry bean, field pea, and lentil for control of seedling blight and damping off. For sunflower, Protege can be applied to the seed at 0.10 to 3.75 fl. oz./cwt for control of damping-off and downy mildew. Protege is also a strobilurin fungicide, with a potential risk of developing fungicide resistant pathogens (see remarks above regarding Headline).

Quadris (azoxystrobin) supplemental labels

Quadris, a fungicide from Syngenta, has added several broadleaf crops and target diseases to the label. New crop additions include chickpea, dry bean, and lentil. It can be applied at 6.2 to 15.4 fl. oz./acre to control anthracnose and Ascochyta diseases, and at 6.2 fl. oz./acre to control rust on dry bean. Soybean rust, although not currently present in the continental United States, has been added as a target disease. The use rate for control of soybean rust is 6.2 to 15.4 fl. oz./acre. Quadris is also a strobilurin fungicide, with a potential risk of developing fungicide resistant pathogens (see remarks above regarding Headline).

Moncut 70 DF (flutolanil)

Moncut 70 DF is a new fungicide from Gowan that is labeled for use on potato. It can be applied in-furrow at 0.71 to 1.1 lb/A or 0.79 to 1.18 oz per 1000 ft row (36 in. rows) to control black scurf (Rhizoctonia solani).

Topsin M and T-methyl (thiophanate methyl) on canola

Topsin M (Cerexagri) and T-methyl (MicroFlo) attained labels on canola for control of Sclerotinia stem rot (white mold). The products can be applied at 1 to 2 lb/acre once at 20 to 50% flowering, or they can be split-applied at 1 lb/acre at 20 to 30% flowering and 1 lb/acre at 40 to 50% flowering.

ApronMaxx RTA on field pea and lentil

The seed treatment fungicide ApronMaxx RTA (Syngenta) has been granted section 24(c) special local need labels in North Dakota for use on field pea and lentil seed at the rate of 5 fl. oz./cwt. ApronMaxx is labeled for protection against seed rot, seedling blight, damping-off, and seedborne Sclerotinia.

Section 18 request update

The following section 18 exemption requests have been submitted to the EPA for the 2003 growing season:

LSP/Mertect LSP on lentil: Approved

Folicur on sunflower: Pending

Quadris on safflower: Pending

Eminent on sugarbeet: Pending

Carl Bradley
Extension Plant Pathologist
cbradley@ndsuext.nodak.edu

 

FUNGICIDE UPDATE FOR CEREAL CROPS, 2003

Two cereal seed treatment products have been registered and several supplemental labels have been obtained for wheat foliar products for North Dakota since publication of the 2003 ND Field Crop Fungicide Guide, NDSU Ext. Pub. PP-622. These products include:

Protege (azoxystrobin) seed treatment: This Syngenta product is registered for seed treatment of barley, corn and wheat, as well as for some broadleaf crops. The active ingredient is 9.6% azoxystrobin. For wheat and barley, the use rate ranges from 0.153 to 0.382 fl oz/cwt and it controls seed-borne and soil-borne fungi causing decay, damping off, and seedling blight. In wheat, this use rate also will provide protection against common bunt and partial control of dwarf bunt. The use rate in corn is 0.153 fl oz/cwt and it is to be used only in combination with labeled rates of Maxim and Apron XL products.

Incentive RTA (difenoconazole + mefenoxam) seed treatment: This Agriliance product is registered for seed treatment of wheat. The active ingredients are 3.21% difenoconazole and 0.27% mefenoxam. The standard rate of 5 fl oz/cwt will provide protection to wheat seed against seed rot, several root rots, common bunt, dwarf bunt, loose smut, and damping off.

Stratego (trifloxystrobin + propiconazole) foliar treatment of wheat: Stratego, a product of Bayer, has a 24(c) special local need label to allow up to 10 fl oz/A of this product to be applied to wheat through Feekes growth Stage 10.5, full head emergence. This label is for leaf disease and glume blotch control. Stratego also has a 2(ee) label to allow a reduced rate for early season tan spot control. The active ingredients of Stratego are 11.4% trifloxystrobin and 11.4% propiconazole.

Headline (pyrachlostrobin) foliar treatment: Headline, a BASF product, was registered very late in 2002 for wheat and barley leaf disease control. The active ingredient in Headline is 23.6% pyraclostrobin. Its use rates are 6.2 to 12.3 fl oz/acre. Headline should be applied no later than 50% head emergence in barley (Feekes 10.3) and can be applied up to full head emergence (Feekes 10.5) in wheat.

Please refer to fungicide labels and specific instructions to get more information about the above products.

Section 18 Update

One Section 18 or emergency exemption request was made for cereals this season. The request for a Section 18 for use of Folicur (tebuconazole) on wheat and barley is still pending.

 

CEREAL RUST UPDATE

Wheat leaf rust pressure was fairly high during the 2002 growing season on late planted, susceptible cultivars. The greatest rust severities were seen in the central and NE counties on late plantings of cultivars such as Gunner, Ingot, Russ and Wallworth. Because the source of rust outbreaks for North Dakota fields are fields of infected wheat in southern plain states, monitoring rust development in those states gives us clues about rust potential in our region.

The Cereal Rust Bulletin #3, published April 23, 2003 by the USDA Cereal Disease Lab, indicated rust development in southern states. The report states that wheat leaf rust was increasing throughout Texas, but overall, leaf rust was lighter than normal for this time of year. Wheat stripe rust was reported to be severe throughout the southern wheat growing areas of the US in April. Wheat stripe rust is favored by cool conditions and generally is not a threat to our wheat crops, although some occurrences were observed in North and South Dakota several years ago.

Marcia McMullen
Extension Plant Pathologist
mmcmulle@ndsuext.nodak.edu

 

NDSU PLANT DIAGNOSTIC LAB UPDATE

Samples are starting to come in to the lab now, mostly greenhouse produced plant material with root rot problems, and spruce with Cytospora canker, Rhizosphaera needlecast, or winter desiccation. We have a new lab technician - Carrie Larson started on November 1, 2002 after Matt Cantin resigned. She is an NDSU graduate in plant pathology and worked with BASF for a year before starting in the lab.

In addition, there are some other changes keeping us busy. The Plant Diagnostic Lab is now part of a larger plant diagnostic network called the Great Plains Diagnostic Network (GPDN) (www.gpdn.org). This regional network is one of 5 established at the federal level. The lead lab in our region is at KSU in Manhatten, KS. The National Plant Diagnostic Network, sub-divided into the 5 regions, was established in response to concerns over deliberate attacks on our food production systems; however, the additional money that is being allocated with this network is providing an opportunity for training, both for us in the lab as well as you in the field, that we have not had resources for in the past. The regional network also connects the nine states by a common sample information collection system and video conference connection so lab personnel will be able to collaborate significantly more than we have in the past. You all have a role in this network as well in that you are considered First Detectors, the eyes and ears of the first line of defense against bioterror threats. You will most often be the first people to see potential problems. We are currently working on training materials to aid you in this role, but please understand that your part in this network is vital to early and successful detection of possible new diseases or other types of attack on our agricultural production systems. Check out the GPDN web site and stay tuned for more details on this network, and ways that it will impact the work we all do.

The other change, to be phased in over the next year, is the joint operation of the Plant Diagnostic Lab with the Soil and Water Testing Labs at NDSU. The Soil and Water Testing Labs will continue to operate, and we hope to more effectively utilize the people we have in all three labs as well as increase testing services. Watch for menus of services we will have available. After next fall, the sample reception areas should be improved and consolidated but for now, please continue to send samples and direct questions to us at:

The NDSU Plant Diagnostic Lab (or PDL)
Walster Hall 306
PO Box 5012
Fargo, ND 58105

We can also be contacted at 701.231.7854, or at:

diaglab@ndsuext.nodak.edu

Cheryl Biller
NDSU Plant Diagnostician
diaglab@ndsuext.nodak.edu

 


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