ISSUE 1   May 15, 2008

FUNGICIDES RECEIVE REGISTRATION FOR WHEAT AND BARLEY

Two fungicides, Folicur (tebuconazole, manufactured by Bayer CropScience) and Caramba (metconazole, manufactured by BASF), have recently received full federal registration from the Environmental Protection Agency for use on small grains in the US. Both fungicides are included in the class of systemic fungicides called triazoles. The availability of these fungicides will give growers increased management options during the growing season.

Folicur previously was available in ND for 11 years through one-year emergency exemptions, but full registration status was finally granted on May 2. The ND Dept. of Agriculture has posted the label through their web site, under their pesticide registration link found at:

http://www.kellysolutions.com/nd/pesticideindex.htm

The Folicur 3.6F label states that 4 fl oz/acre may be applied to wheat and barley, to control rust diseases and suppress Fusarium head blight. The pre-harvest interval for Folicur is 30 days. Grazing livestock or feeding of green forage is permitted 6 or more days after the last application. A spray surfactant is recommended to be used with Folicur. The ND pesticide registration base, as indicated in the link above, also indicates that Orius, MANA’s version of tebuconazole, has received labeling, as well.

With Folicur available, Bayer CropScience has also developed a label for Folicur + Proline (prothioconazole) for use in 11 states, including ND, MN, SD, and MT. This label is for 3 fl oz of Folicur + 3 fl oz of Proline for the suppression of Fusarium head blight and control of leaf diseases, such as leaf rust Septoria, and tan spot. This combination was widely used in ND in 2007, under the emergency exemption for Folicur and the full registration for Proline.

Caramba is a new registration, also just received, and the label may be found at the above web link to the ND Dept. of Ag. pesticide registration information. Caramba is registered for wheat, barley, oats, rye and triticale. The use rate for Caramba is 10 fl oz/acre for leaf diseases and 14-17 fl oz/acre for suppression of Fusarium head blight. For applications of 5 gpa or more, an approved adjuvant is recommended at standard rates is recommended. The pre-harvest interval is 30 days, and no livestock feeding restrictions are indicated.

BASF has another new federal labeled product, called Multiva, a combination of Headline (pyraclostrobin) and Caramba (metconazole). As of May 9th, 2008, this label was not yet posted on the ND registration site. Multiva use will be aimed at leaf diseases of the small grain crops, at a 6-11 fl oz/acre rate, but indications from BASF are that it may not be marketed in this region, at least for 2008.

Complete information on pricing, availability, and strategies for use and specific disease control of these products should be obtained from the company representatives in the area. The good news for farmers is that all are excellent products and provide the means for good fungicide disease control strategies throughout the growing season.

 

CEREAL RUST UPDATE FROM ST. PAUL

Wheat leaf rust:

The USDA Cereal Disease Lab’s latest Cereal Rust Bulletin, May 6th, indicates that wheat leaf rust is widespread and increasing rapidly throughout the southern US. Susceptible winter wheat cultivars, such as Jagalene and Jagger are showing severity levels of up to 65% on flag leaves in Oklahoma. The disease is also visible in Kansas on these cultivars, and at trace levels on the more resistant cultivars, Overley and Fuller. Repeated rains across the southern plains has favored rust development.

The occurrence of rust indicates a potential threat to our susceptible winter and spring wheats, if sufficient rainfall should occur for infection. It is too soon to know how big of threat we have, but the occurrences and spread bear watching. Information on susceptibility of winter wheat cultivars may be found at the web site:

http://www.ag.ndsu.edu/pubs/plantsci/smgrains/a1196.pdf

This is the web access to NDSU Circular A-1196 North Dakota Hard Red Winter Wheat Variety Trial Results for 2007 and Selection Guide

Information on spring wheat variety response to leaf rust may be found at:

http://www.ag.ndsu.edu/pubs/plantsci/smgrains/a574.pdf

This is the web access to NDSU Circular A-574 North Dakota Hard Red Spring Wheat Variety Trial Results for 2007 and Selection Guide

Wheat stem rust:

Wheat stem rust has been found in Texas, and levels are slightly higher than last year. The stem rust race so far identified is a common race in the US and is avirulent to most of the winter and spring wheats in the US.

An emerging, virulent stem rust race (commonly called UG99) was found in Uganda, Africa in 1999, and the scientists at the USDA lab in St. Paul, and others around the world are tracking the movement of this race and evaluating germplasm and existing cultivars for resistance. This race recently was found to have moved into Iran from Yemen. This stem rust race may attack many cultivars (including those grown in ND) and is particularly an immediate threat to vulnerable regions of the world with few resources. In early April, 2008, the Bill and Melinda Gates Foundation announced a $26.8 million grant to Cornell University to produce a partnership for Durable Rust Resistance in Wheat, a partnership of 16 institutions in 13 countries, working together for the next 3 years to track the spread of the pathogen and screen genetic resources for resistance. This project will benefit all wheat breeding programs. More information about the new project can be found at http://www.wheatrust.cornell.edu.

Oat crown rust:

This leaf rust of oats has been found in south and central Texas, and these southern locations may provide inoculum for the northern oat growing areas, as the season progresses. Variation in oat variety susceptibility exists, and information may be found at:

http://www.ag.ndsu.edu/pubs/plantsci/smgrains/a1049.pdf

This links to NDSU Circular A-1049, North Dakota Barley, Oat, Rye and Flax Variety Trial Results for 2007 and Selection Guide. Table 6 contains information on oat variety response to crown rust.

Barley rusts have not been reported yet this year.

Marcia McMullen
Extension Plant Pathologist
marcia.mcmullen@ndsu.edu

 

SUGARBEET CROP UPDATE

Late snow and cold conditions have delayed planting of sugarbeet in North Dakota and Minnesota.

As of May 13, American Crystal Sugar Company growers have completed planting 92% of their acreage. The Moorhead factory district was the furthest behind because of wet field conditions. Minn-Dak Farmers Cooperative growers have completed about 55% of their planting. Southern Minnesota Beet Sugar Cooperative growers have completed planting about 45% of their acres, with planting conditions slightly more favorable in the western part of the district.

The sugarbeet crop will be off to a slow start since soil temperature is below normal for this time of the year. Low soil temperature will delay germination and emergence. It would be particularly useful to have a cover crop to protect seedlings especially on soils that ‘blows’. Oats and barley at three quarters to one bushel per acre are widely used as cover crops. The cover crop should be killed when sugarbeets are in the three to four leaf stages.

 

PLANT POPULATION FOR HIGH SUGAR BEET YIELD AND QUALITY

It is sugar beet planting time again! Our research shows that maximum recoverable sucrose per acre correlates well with plant population.

Research done at North Dakota State University and the University of Minnesota showed that a plant population of 175 to 200 plants per 100 foot of 22 inch wide rows was ideal for maximum recoverable sucrose per acre. It is important that the plants be evenly spaced within the rows.

At lower plant populations – say at 100 to 125 plants per 100 foot of row, roots tend to be somewhat larger but there is generally a reduction in yield because of the lower population, and sucrose concentration decreases resulting in higher processing costs. Lower plant populations take longer for the canopy to completely cover the soil resulting in a more costly weed control program.

Higher plant populations of 225 plants per 100 foot of row result in too much competition among the plants and consequently smaller sugarbeet roots and lower recoverable sucrose per acre compared to plant populations of 175 to 200 plants per 100 foot of row. Defoliation becomes very difficult at such high plant populations. Sugar beet fields with 225 plants per 100 foot of row planted at 22 inch row spacing should be thinned to about 175 to 200 plants per 100 foot of row.

Plan to have a good plant population of 175 to 200 plants evenly spaced per 100 foot of row for highest sugar beet yield and quality. Growers who use 30 inch row spacing should aim for about 215 to 225 plants per 100 foot of row to get highest yield and quality.

 

PROJECTIONS FOR 2008 SUGARBEET CROP

Total sugarbeet acreage in the US for 2008 was projected at about 1.247 million acres; a 4.3% reduction from the 2007 sugarbeet crop.

American Crystal Sugar Company will plant about 418,000 acres, Minn-Dak will plant 105,000 acres, and Southern Minnesota Beet Sugar Cooperative will plant 108,000 acres. Growers in Western North Dakota and eastern Montana will plant about 15,000 acres for the processing plant in Sidney, Montana. North Dakota and Minnesota will plant just over 50% of the total US sugarbeet acreage.

Growers can improve efficiency by properly preparing seed beds, using starter fertilizer where appropriate, using adequate seeding rate to start with a good plant stand and timely application of herbicides for effective weed control to give their crop a good foundation. Last year, growers had a good sugarbeet crop. The costs for inputs are increasing significantly. Growers need to strive for a 23 ton/acre crop with a high sugar concentration to remain economically viable.

 

SOIL TEMPERATURE AND SUGARBEET SEED EMERGENCE

Sugarbeet seeds germinate and emerge over a wide temperature range in the presence of adequate soil water. In most years, soil temperature at the 4-inch depth at planting time in mid-April is about 45 F. However, unusually low temperature in April and early May has resulted in growers planting into a colder seedbed. This means that the sugarbeet crop and all its weeds will emerge slower than usual. The following table gives approximate days to emergence at different soil temperature ranges.

Soil Temperature ( F)

Days to Emergence

38-45

21 days or more

45-52

10-21 days

52-60

7-12 days

60-70

5-7 days

Mohamed Khan
Extension Sugarbeet Specialist
701-231-8596

 

CERTIFIED SEED AN IMPORTANT STEP TO MANAGING BACTERIAL BLIGHTS OF DRY BEANS

Bacterial blights can damage yield and quality of dry edible beans in North Dakota. Because these disease can be seedborne, the most important prevention technique is to plant certified, disease-free seed. Planting certified seed may be particularly important this year due to the favorable environment for bacterial blights in North Dakota last summer. With bacterial blights, it is much easier to try and prevent infection rather than to treat it later. Crop rotation is also an important management step, and streptomycin sulfate is labeled as a seed treatment but cannot cure internal infection. As grandmother always said, an ounce of prevention is worth a pound of cure, and certified seed is a critical step in prevention.

 

CONSIDERING A FUNGICIDE SEED TREATMENT ON SOYBEANS?

Predicting whether a seed treatment will pay on any given field, in any given year, is pretty tough to do. But we can discuss a few risk factors, which may indicate whether a seed treatment will be beneficial to you.

Temperature. When soils are cool (less than 60 F) soybeans germinate more slowly, this increases their exposure to numerous pathogens that are lurking in the soil; including Phytophthora, Pythium, Fusarium and Rhizoctonia. This year, our soils temps have generally been below average.

Water. Wet soils are more likely to provide a favorable environment for root rot pathogens. Some of these pathogens need water to cause infections and disease; some just cause more disease in a wet environment. Sometimes parts of the field appearing to have water damage may actually have been damaged by root rot pathogens. Standing water in moderation may hurt the plants some, but they also provide an extremely favorable environment for the pathogens. We have had lots of variation in rainfall statewide, but if you are in an area with wet soils, you may be at greater risk.

Disease History. If you have had stand establishment/root rot problems in the past, you may be at greater risk for root rot damage Spots in the fields with thin plant stands, or plants that appear drought stressed when there is adequate moisture and unthrifty looking could indicate symptoms of root rots.

Crop Rotations. Tight crop rotations give the pathogens an opportunity to build up in the soil, while longer crop rotations can reduce the numbers of some pathogens. High populations of plant pathogens are more likely to do damage.

Even if you don’t have all the risk factors, seed treatments may be a good option. In a two-year study done at seven different locations in ND, the average return on seed treatments across all those environments was $10-20/acre. This was assuming the price of $5.45, which is not the case anymore.

When choosing a fungicide treatment, it is best to apply a product with activity against Pythium and Phytophthora (mefenoxam or metylaxyl for example) and Fusarium and Rhizoctonia (azoxystrobin or fludioxonil for example). A good synopsis of fungicide protection against different pathogens was published by the University of Nebraska Extension Service (University of Nebraska NebFact NF411), and is available at:

http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=377

For current seed treatment products in North Dakota, check the 2008 North Dakota Field Crop Fungicide Guide (PP-622) available at:

http://www.ag.ndsu.nodak.edu/extplantpath/.  

Always read and follow the manufactures label.

Sam Markell
Extension Plant Pathologist
samuel.markell@ndsu.edu

 

NDSU POTATO BLIGHTLINE TO OPERATE IN 2008

The Plant Pathology Department at North Dakota State University will again be providing the potato blightline service at no charge to the potato industry of North Dakota and western Minnesota in 2008. This will be the fourteenth year that this service has been provided and sponsored by Syngenta Crop Protection. The hotline uses local weather data collected from weather stations throughout our area to forecast the occurrence and spread of late blight in fifteen non-irrigated and twelve irrigated production areas in ND and western MN. The data is processed by the North Dakota Agricultural Weather Network (NDAWN) and analyzed by a computer program (WISDOM) to forecast when conditions are favorable for late blight to occur. The forecast information is used by plant pathologists Gary Secor and Neil Gudmestad to make late blight management and fungicide recommendations. The recommendations are made Monday, Wednesday and Friday of each week during the growing season. The first late blight hotline will be Monday June 2nd, and it is anticipated that the hotline will continue through mid September depending on disease pressure. The hotline will also be used to confirm reported late blight sightings and serve as clearing house for national late blight information. In addition to late blight forecasting, the hotline also provides cumulative P-values for early blight disease forecasting and management recommendations. Finally, it serves to alert growers of other disease and insect news, as well as posting messages of general interest such as potato field day dates.

The hotline recommendations can be accessed by phone or website. The toll free phone number is 888.482.7286

The NDAWN website for potato disease forecasting contains colored maps of ND to pictorially illustrate the late blight severity values (both two day and seasonal), favorable day values and P-day values for early blight throughout ND. That site is:

www.ndawn.ndsu.nodak.edu  

Go to applications and then click the potatoes drop down box.

Growers and scouts are encouraged to send suspect late blight samples to us for positive identification. Late blight is a community disease and proper identification and prompt notification is important. Leaf samples should be placed in a slightly inflated zip-lock plastic bag without a wet towel and sent to:

Gary Secor, Plant Pathology, Walster Hall 306, NDSU, Fargo, ND 58105. Our phone number is 701.231.8362 and email address is gary.secor@ndsu.edu. We look forward to a successful potato year.

Gary Secor
Plant Pathologist
gary.secor@ndsu.edu


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