Volume 5 Issue 10     July 22, 2008

Upcoming Plot Tours
Soybean Plots   --  Fosston   --   July 30
Corn Fertility Plot  --  Moorhead  --  July 31
Soybean, Corn, and Fertility Plots  --  Crookston  --  July 31
Corn Fertility Plots  --  Ogema  --  August 1

Soybean Aphid Populations Coming
on Strong in West Central and NW Minnesota
Soybean aphid populations in the region are increasing steadily. Infestations in fields are still quite variable, however. There are fields that have reached threshold numbers of 250 aphids/plant and greater. There are still fields where it is very difficult to find aphids. And, there is everything in between.

Three New Soybean Aphid Insecticides
All are restricted use pesticides. Pre –harvest intervals (PHI) and re-entry intervals (REI) do not necessarily correspond to the duration of insecticide activity. The following is not intended as an endorsement of any product. READ THE LABEL!

Time to Scout  for Banded Sunflower Moth
Banded sunflower moths have begun to emerge in the region and will require field scouting to determine the populations present within fields. The banded moth has been one of the more persistent sunflower insect pests in the past ten years and was again responsible for seed damage and many of last year’s insecticide treatments applied during flowering

“It's always something…”:  Sunflower Bud Moth
As usual, what started as a slow bug year has thrown me a spitball.  Sunflower bud moth has been reported from numerous locations in eastern ND and western MN.  What has been showing up is black, granular material on the stalk or around the base of the developing head – this is frass (bug poop), and a sign that sunflower bud moth larvae are feeding.

Time to Scout for Rust on Sunflower:
Spore loads are building in North Dakota
Last week Dr. Sam Markell, Extension plant pathologist at NDSU released a cautionary press release to North Dakota sunflower producers concerning the increasing risk for sunflower rust to cause significant damage to that state’s crop.  Locations of most concern were western North Dakota extending as far east as the Mohall area.  Additionally, Dr. Markell stated that sunflower rust was present near the North Dakota-Minnesota border at much lower levels. 

NDSU Extension Bulletin 25 (Revised Sept. 2007)
Edited and Compiled by Duane R. Berglund
Professor Emeritus and Former Extension Agronomist
North Dakota State University Extension Service 

Wheat Streak Mosaic Virus Confirmed in Minnesota
The diversity of diseases on spring wheat is increasing in the Red River Valley.  On July 15, Ardell Knudsvig, Plant pest surveyor with the Minn. Dept. of Agriculture sampled symptomatic plants from a flowering wheat field in Roseau County. 

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