AgAlerts 2001 From Griggs County
By John Swenson, Griggs County Extension Agent

Issue # 9, July 23, 2001

• Last Chance For Project Safe Send Tuesday, July 24, 2001

• Painted Lady Butterflies, Fill the Air

• Sunflower Beetles Continue to Defoliate Sunflower

• Banded Sunflower Moths

• Lodge Small Grains

• Downy Mildew Causing Concerns in Sunflower

• Top Wheat Varieties Planted in 2001

Last Chance For Project Safe Send Tuesday, July 24, 2001

Valley City - DOT - 1524 8th Ave SW, south of I-94 at Exit 292.
9 a.m. - 3 p.m. local time - Tuesday, July 24

Painted Lady Butterflies, Fill the Air

    Thousands and thousands of painted lady butterflies have emerged from their chrysalls (cocoons) and very present on road and vehicle grills and windshields.  This is the third generation of this insect.  They are now mating and laying eggs on Canada thistle, sunflower and maybe soybean.  Be prepared to monitor sunflowers and soybeans in the next week to see if they are causing feeding damage.  I have had reports on the lifecycle and control measures in previous issues of AgAlerts (Issue # 7 and Issue # 8).  The following pictures are of adults in a local sunflower field.  These butterflies are sometimes confused with the monarch butterfly, but the monarch is larger and does not have the gray color on the under side of the wings.

            (Click on photo's to enlarge)

Sunflower Beetles Continue to Defoliate Sunflower

    I have been called out to several sunflower fields in the eastern part of Griggs County and sunflower beetle thresholds of 10 to 15 per plant were present in several of these fields.  Confection growers are hoping to be able to treat sunflower seed weevil and sunflower beetle with one application.  In some cases of early planted flowers this might be possible.  But, if flowering is going to be in a week and threshold and defoliation levels are already present, the question becomes can you wait to treat for both.  

Banded Sunflower Moths 

    Banded sunflower moths have been reported by NDSU field scouts in grass areas surrounding sunflower fields.  Banded sunflower moth larvae feed on developing sunflower seeds.  An easy way to determine damage by banded sunflower moth or seed weevil is where the exit hole is located.  Banded sunflower moth larvae will exit at the top of a sunflower seed while seed weevils exit on the side near the top of the seed.  Confection buyers will deduct if banded sunflower moth feeding is present in a sample.  The banded sunflower moth will lay their eggs during bud development.  If sunflower beetle is to be treated at this time, it will also control banded sunflower moth.  For information, contact banded sunflower moth.  For insecticides cleared for control consult the 2001 Insect Pest Management Guide.

Lodged Small Grains

    Storms over the past week have caused small grains to lodge.  What effect on yield will depend on the stage of the crop, the weather in the next week and how much the crop can bring it's self back up.  The stage on the crop will determine how heavy the heads are.  It is easier for a crop that was just flowering to respond than a crop that was in late milk to soft dough.  Barley is farther along and will respond the poorest.  Factors that will affect yields will be how the crop will fill in a lodged position and disease pressure.  The crop should fill if the stems are not kinked or damaged.  Diseases, such as scab or septoria, could become a problem due to the wet, humid environment.  We need dry, windy weather to help with disease suppression.  Losses are hard to predict, but under moderate to severe lodging we could possible see 10 to 25 percent losses.  Only time will tell.  
    There are some possible reasons for this crop to lodge.  The small grain crops were very lush and thus stem strength was less than usual.  Fertility, whether it was high nitrogen levels or an imbalance  between nitrogen and phosphorous caused stem strength to be poor.  Phosphorous has a big influence on stem strength.  Also the stem strength of the variety.  These factors, or other factors are going to be looked at this year for future recommendations.
    The following table lists commonly grown varieties and their characteristics.

  Downy Mildew Causing Concerns in Sunflower

    Downy mildew is showing up in most sunflower fields.  This disease is one on which I have reported on in previous AgAlerts (Issue # 6).  The following pictures show damage symptoms in previous wet soil conditions.

                (Click on photo's to enlarge)

Top Wheat Varieties Planted in 2001

For a complete variety listing check out "2001 North Dakota Wheat Varieties".

Please Contact Our Office For Additional Information
E-mail: griggs@ndsuext.nodak.edu
Go to the 2001 AgAlert Index Page