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ISSUE 1  May 3, 2001

 

ART LAMEY TO RETIRE

Dr. Art Lamey, Extension Plant Pathologist at NDSU for 24 years, will retire from his position on June 1. Art has been a wealth of disease management information for ND producers, extension agents, and ag industry over these years, and he will be sorely missed. The good news is that he will continue to work part time as a consultant for the Northern Canola Growers Association as well as lead an extensive field survey of sunflowers this fall.

 

PLANT PATHOLOGY CONTACTS THIS SUMMER

A committee has been established to refill Art Lamey’s Extension position, but a replacement won’t be in place this summer. For questions about certain crop diseases and their management, the following persons may be contacted:

Crop

Disease

Phone contact

Canola, Crambe

All

Art Lamey
701-231-7056

Chickpea,
Field Pea

All

Kent McKay
701-857-7682
Duane Berglund
701-231-8135

Dry Bean

All

Luis del Rio
7011-231-7073

Flax

All

Marcia McMullen
701-231-7627

Forages

All

Marcia McMullen

Ornamentals,
Home Garden

All

Cheryl Biller, Diagnostic Lab
701-231-7854

Potato

All

Duane Preston
218-773-9614
Gary Secor
701-231-7056
Neil Gudmestad
701-231-7547

Small Grains

All

Marcia McMullen

Soybean

Root rots

Marcia McMullen
Berlin Nelson
701-231-7057

Soybean

White mold

Luis del Rio
Marcia McMullen
Berlin Nelson

Sugarbeet

Cercospora

Mohamed Khan
701-231-8596
Marcia McMullen

Sugarbeet

Root rots

Mohamed Khan,
Marcia McMullen,
Carol Windels, U of MN, Crookston
218-281-8608

Sunflower

All

Marcia McMullen

 

EARLY SEASON RUSTS IN SOUTHERN PLAINS

Two Cereal Rust Bulletins have already been published by the USDA Cereal Lab in St. Paul. Their second bulletin, published April 18, indicates that no wheat stem rust has been reported in the US and only light amounts of wheat leaf rust have been observed in central Texas. Cooler than normal weather in March contributed to the slow stem and leaf rust development in the southern US. These cooler than normal temps have contributed to some high severities of wheat stripe rust, however, in south-central Texas. Wheat stripe rust was observed in plots in SD and ND last year, but generally temperatures get too warm for this rust to develop extensively. No barley stem rust has been observed and only light levels of oat stem rust have been observed in Texas. Oat crown rust was severe on common and wild oat in central Texas in mid-April.

 

NEW NORTH DAKOTA IPM WEB PAGE

A new web page highlighting ND IPM activities has been developed. This web site has links to many NDSU web pages, as well as links to regional and national sources of IPM information. Please check out the following site, and provide me with any suggestions:

www.ag.ndsu.nodak.edu/aginfo/ndipm/

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

 

SNOW MOLD IN LAWNS AND BLACK KNOT ON PRUNUS

Snow Mold

By now, most people are relieved that the snow is finally gone. However, a drawn out spring with periodic warming periods followed by more snow fall have left large brown patches in many lawns. Fungi that cause snow mold usually become established in late fall, and then actively grow and cause injury symptoms in late winter and early spring. Snow mold is characterized by the appearance of matted patches of grass that are white to gray or lightly pink in color. Webbing or a fuzziness may be apparent with gray snow mold whereas a tannish-pink discoloration on the leaves is more typical of pink snow mold. Where gray snow mold is present, it is possible to find small, black beads on the blades of grass or in the matted lawn. These are the overwintering structure for the fungus. Due in part to the presence of these hard black bodies, called sclerotia, snow mold typically occurs in the same areas each year.

Despite its widespread appearance, treatment is often relatively easy and inexpensive. Raking the matted areas is usually sufficient to break up the mycelium or growing body of the fungus, and stop progress of the disease. The activity of raking can be tough on grass, though, and it is better to wait to rake until temperatures are above 50 degrees F, and the soil is not still soggy. In most cases, this is all that is required and the grass recovers with increasing temperatures. However, this year presented some severe conditions in parts of the state. Alternating warm periods followed by a return to colder temperatures and snow meant longer periods of pathogen activity. Standing water in some areas only compounded the stress on some lawns. The result is patches of varying size that may have been killed. If these areas do not begin to show signs of greening up within the next couple weeks, re-seeding with an appropriate mixture of seed in those areas may be necessary. Seed mixes should contain Fusarium-resistant Kentucky bluegrass, and be either shade tolerant or for sunny areas, depending on where the dead spots are located.

Black Knot

Now is a good time to scout Prunus species (chokecherry, plum) for the telltale sign of Black Knot. The fungus that causes this disease, Apiosporina morbosa, overwinters on twigs and branches as a mass of fungal fruiting structures that appears like a corky, swollen, and very black "knot" on the tree. These knots represent older infections and are easier to see in a tree before the leaves are fully out. New infections in a tree occur when spores produced in these knots in the spring are windblown or rainsplashed to wounds or new green growth; and they may occur in the same tree in or in previously healthy trees near by an infected tree. New infections in a tree will appear as olive-green swellings on a branch, often swelling to the point of cracking the bark.

There is no fungicide specifically for this disease. The only way to treat infections (both old and new) is to prune them out. Pruning cuts should be made 3-4 inches below the knot or swelling. Remove and destroy pruned branches so that spores from the knots cannot infect other trees. Lime sulfur may be used as a dormant spray after removal of the knots. This disease is relatively easy to control by removing knots as they appear, but wild plants or neighboring trees that are left unmanaged could continue to cause new infections. It is best to completely remove heavily infected trees. Look for resistant varieties of trees when replacing or planting new trees.

Cheryl Biller
Diagnostician

diaglab@ndsuext.nodak.edu

 

DUPONT TO PHASE OUT SALE OF BENLATE®

The following is a news release from duPont:

WILMINGTON, Del, April 19, 2001 -- Today DuPont informed its customers around the world that it will discontinue the manufacture of its fungicide benomyl and will phase out sales of Benlate® in all its forms from the global market. No sales will occur after December 31, 2001, and we expect all product will clear the channels of trade by the end of 2002.

DuPont advised customers that this is not a product recall, but a voluntary business decision based on a review of global market conditions and other factors. The decision is part of the recently announced restructuring to improve the overall competitiveness of its agricultural businesses.

A significant element of the reason to withdraw is that the company is no longer willing to bear the high and continuing costs of defending the product in the U.S. legal system where factors other than good science can influence outcomes. In addition, there are significant ongoing costs and resources necessary to meet increased regulatory requirements around the world and keep the product active. The company believes those resources are better applied to other areas of the business.

DuPont remains fully confident that Benlate® is safe when used as directed. The 30-year-old fungicide has been an excellent crop protection option for growers worldwide.

For attribution to James C. Borel, vice president & general manager - DuPont Crop Protection

4/19/01

What does this mean in North Dakota? This means that the use of Benlate on dry beans and wheat will cease once existing supplies are exhausted sometime in 2002. We had been hoping that Benlate would be registered for canola by 2002. Now it appears that this registration will not happen and that Canada will lose the use of Benlate on canola by the end of 2002.

 

SEED TREATMENT OF CHICKPEAS

There have been some questions about seed treatment of chickpeas. Seed treatment with LSP (state label in North Dakota) is advised for control of seed borne Ascochyta. LSP should be used in conjunction with good quality seed. DO NOT attempt to use LSP to clean up poor quality bin run seed! In addition, seed should also be treated with Allegiance or Apron XL to control Pythium seed rot and damping off.

Art Lamey
Extension Plant Pathologist

alamey@ndsuext.nodak.edu


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