ISSUE 1   May 6, 1999

APRON MAXX RTA STATE LABEL FOR SOYBEAN SEED TREATMENT DENIED

    State labels (24c or SLN) were granted for the use of Apron Maxx RTA in 10 states. Both
of the active ingredients Apron XL and Maxim are registered for soybean seed treatment. Denial
by the Environmental Protection Agency was due to an ingredient other than the Apron XL or
Maxim contained in the product.

    All shipments and sales of Apron Maxx RTA have been stopped as of April 22, 1999. All
product at distributors is being recalled.

    Any seed already treated may be planted. Any open containers may be used and seed treated
from those open containers may be planted. Novartis Crop Protection assures that the other
ingredient will have no adverse effect on product performance.

GUSTAFSON LSP STATE LABEL FOR CHICKPEA SEED TREATMENT

    The North Dakota Department of Agriculture granted a state label for the use of Gustafson
LSP for seed treatment of chickpea to control seed borne Ascochyta. LSP contains thiabendazole.
Ascochyta is a major chickpea disease and LSP is highly effective against seed borne Ascochyta.
The use rate is 3.3 fl oz/cwt.

MAXIM MZ STATE LABEL FOR POTATO SEED PIECE TREATMENT

    The North Dakota Department of Agriculture granted a state label for the use of Maxim MZ
for potato seed piece treatment. This product contains Maxim (fludioxonil) plus mancozeb.
It is registered for control of Fusarium dry rot seed decay, seed borne Rhizoctonia that causes
stem canker and tuber black scurf, and seed borne silver scurf. It does not control bacterial
disease nor diseases present within the seed. The use rate is 0.5 lb/cwt.

    The North Dakota Department of Agriculture granted a state label for the use of MZ Curzate
for the treatment of potato seed pieces. This product contains Curzate (cymoxanil) and mancozeb.
It is registered for prevention of spread of potato late blight from infected or surface infested
seed pieces. It also aids in the suppression of Fusarium dry rot. The use rate is 0.75-1.0 lb/cwt.

    The North Dakota Department of Agriculture granted a state label for the in-furrow application
of Ridomil Gold EC on potato. This treatment is highly effective against pink rot and leak. In the
past, Ridomil was applied when the tubers were starting to form, but this application does not fit
into current late blight practices. In-furrow application is an economic alternative for suppression
of pink rot and leak. Use rate is 0.42 fl oz/1,000 ft of row in a 6-8" band directly over the seed pieces.

SECTION 18 GRANTED FOR LSP SEED TREATMENT OF LENTIL

    A section 18 was granted for the use of LSP seed treatment on lentils for control of seed borne
Ascochyta. LSP contains thiabendazole, which is highly effective against seed borne Ascochyta.
The section 18 covers the use of both Gustafson LSP and of Mertect LSP. The use rate is
1.7-3.0 fl oz/cwt.

Art Lamey
Extension Plant Pathologist
alamey@ndsuext.nodak.edu

FOLICUR FUNGICIDE RECEIVES SECTION 18 EMERGENCY EXEMPTION FOR USE
ON WHEAT AND BARLEY

    Folicur 3.6F received a Section 18 Exemption for use on wheat and barley in North Dakota
for 1999. The use rate is 4 fl oz/acre and a maximum of one application per season may be made.
Folicur may be used up to within 30 days of harvest, and the Section 18 label also states it may
be applied up to the 50% heading stage. This Section 18 was requested for suppression of
Fusarium head blight (scab). Folicur also has good activity against common wheat and barley
leaf diseases. The active ingredient in Folicur is tebuconazole, a systemic compound with a
broad spectrum of activity. The Section 18 exemption allows Folicur to be used on 2 million
acres of wheat and 250,000 acres of barley in North Dakota in 1999. Last year’s price for
Folicur was about $9.15/acre; I don’t have a price for 1999.

QUADRIS FUNGICIDE LABELED FOR WHEAT

    Quadris fungicide, manufactured by Zeneca, recently received a supplemental label for
application to wheat. The active ingredient in Quadris 2.08SC is azoxystrobin. This compound
is one of the strobulurins, a new family of fungicides with a novel mode of action. Quadris is a
broad spectrum, preventative fungicide with partial systemic activity. For wheat, it has activity
against leaf rust, stem rust, the Septoria diseases, tan spot, and powdery mildew. The suggested
use rates vary from 6.2 fl oz product per acre to 10.8 fl oz/acre. The higher rates are recommend
for best control of tan spot or powdery mildew. Applications can be made by air, ground, or
chemigation. The suggested retail price of Quadris is around $300/gallon, translating to $14.50
to $25.30/acre, depending on rate used.

    We have tested Quadris in North Dakota and it has performed well against the leaf diseases at
rates of 6.2-12.4 fl oz/acre. We have also tested its performance against Fusarium head blight
(scab), at 9.3 - 12.4 fl oz/acre. At the 12.4 fl oz/acre rate, Quadris performed well against FHB
in 1998, but it performed less satisfactorily than some other compounds in 1997. We are
including Quadris at the 9.3 and the 12.4 fl oz rate in the Uniform Fusarium head blight fungicide
trials in 1999.

OTHER PRODUCTS AVAILABLE FOR FOLIAR APPLICATION TO WHEAT AND/OR BARLEY, 1999

    Benlate, various mancozebs, and Tilt fungicide are also registered for small grains in 1999.
Benlate is registered for wheat only, and may be applied up to 21 days before harvest. Benlate
is a systemic product that has good activity against Fusarium head blight (head scab). The
various mancozeb products are protectants and are registered for wheat and barley; they control
leaf diseases and suppress head scab, and have a 26 day pre-harvest interval. Tilt fungicide is
registered for wheat and barley, with a maximum of 4 fl oz/acre allowed per season. The active
ingredient is propiconazole which is a systemic with a broad spectrum of activity. The federal
label for Tilt for wheat and barley still has an application timing of early flag leaf emergence,
but Tilt has a 2(ee) label for early season application to wheat for early season leaf disease
control, and Tilt has a 24C label (state label) for application to headed wheat (Feekes 10.5
growth stage), for Septoria glume blotch and head scab control. In addition to the above
fungicides, copper fungicides, a mancozeb and copper combination (Mankocide), and Bayleton
also are registered on small grains. Bayleton is labeled only for wheat, for control of powdery
mildew and rusts.

WHEAT LEAF RUST UPDATE

    Wheat leaf rust was much more severe and widely distributed than normal in wheat fields
and plots in central Texas in April, 1999, according to the most recent Cereal Rust Bulletin
(Bulletin #2, Cereal Disease Lab, USDA, St. Paul). In central Texas, where moisture was available,
leaf rust development was heavy, and leaf rust severities of 80% were observed on a susceptible
winter wheat, TAM-107. Only light levels of leaf rust were reported in Kansas as of April 23.
These areas have seen considerable rain the past 10 days, which may further the rust development.

The progress of leaf rust to our south bears watching, to determine the potential threat to most
of our winter wheat varieties and some spring wheat varieties later on.

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

NDSU PLANT DIAGNOSTIC LAB OPENS THE 99 SEASON

    On April 1^st, the Plant Diagnostic Lab officially opened for another growing season.
Both support staff personnel are returning this season. Matt Cantin was hired as Plant Diagnostic
Lab technician in January, and Janet Thompson returns as the lab assistant. Matt, Janet, and Cheryl
will try to assist you in any way we can.

    The lab offers insect and plant identification, disease diagnosis, visual herbicide injury diagnosis,
cultural information, and control recommendations. To submit a sample, collect as much of the
living plant as possible. If possible, send several plants showing similar symptoms; and include a
"healthy" plant for comparison. For tree samples, send one or several branches showing the
symptoms of concern. If possible, take a branch with both injury symptoms and some green,
healthier material. Leaves from any plant should not be wrapped or packed with wet paper toweling
of any kind. Simply place the leaves between pieces of paper. Root masses are the only part of a
plant that may be wrapped in plastic, but never seal a plastic bag. Insects are best sent in vials of
alcohol or placed on loose packing material in a box. Please don’t send live insects in the mail for identification.

    Samples should be submitted with a Plant Diagnostic Lab Form. If a form is not available to you,
include your name, address, phone number, email address (if appropriate), and a written narrative
that contains field or planting history, pesticides and fertilizers applied, age of the plant, when
symptoms were first observed, and any other information that may be relevant. A more complete
history and narrative will make it possible for the lab to provide a more thorough and specific
response.

    The fee schedule remains the same as it was last year with some additional testing services offered:

The lab is located in Waldron Hall, room 206. Samples may be delivered directly to the lab or sent to:

NDSU Plant Diagnostic Lab
Walster Hall 306
Fargo, ND 58105

Telephone inquiries may be directed to: 701.231.7854

Cheryl Ruby
Plant Diagnostician
diaglab@ndsuext.nodak.edu