North Central Research Extension Center


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June 23, 2010

Small grains:

Moderate to severe infections of tan spot are common throughout the area.  Winter wheat that is heading has a moderate risk for scab infections.  Stripe rust was observed on winter wheat.  The triazole fungicides that control scab are also very effective against stripe rust (Marcia McMullen, Extension Plant Pathology).   Consider using the full rate of fungicide under the high disease pressure that we have been experiencing this season.  A four ounce rate of propiconazole (Tilt, PropiMax, Bumper) will provide control up to 20 days as compared with 10 day control with a 2 oz. rate (Marcia McMullen, Extension Plant Pathology).      

Peas, Lentils, and Chickpeas:

Peas and Lentils are beginning to bloom in some areas.  Fields should be scouted during full bloom for pea aphids and Lygus bugs.  We continue to see pea aphids in pea and lentil fields and have begun seeing Lygus bugs.  Lygus bugs cause a problem known as chalk spot in peas and lentils.  Bacterial blight and root rots are prevalent throughout the area.  As the temperatures rise, bacterial blight will dry up and no longer be a problem (Sam Markell, Extension Plant Pathology).  There have also been reports of Ascochyta in chickpeas and field peas.  A key fungicide timing for this disease is at bloom.  Resistance management should be employed by rotating fungicides with different modes of action ( 


Lygus bugs have been caught in blooming canola fields.  At average application costs and canola prices, canola should be treated for Lygus bugs at the end of flowering if more than 15 bugs are caught in 10 sweeps (1.5 bugs/sweep).  Please refer to the following website for more specific information including different thresholds for cost and price variation:$department/deptdocs.nsf/all/agdex741

Diamond-backed moth (DBM) larvae have been found in a blooming canola field at the North Central Research Extension center.  Canola is most susceptible to injury from DBM at bloom to early pod development.  Insecticide applications are justified when two or more larvae per plant are found throughout a field.  For more information see:

The risk for flea beetle damage has passed because the vast majority of fields in the area are near or beyond the six leaf stage. 


Sunflower beetle adults and larvae were found by our IPM scout, Asanga Manamperi, in low numbers in a field in the area.  Insecticide seed treatments have done a good job of reducing populations of this pest in recent years.  However, as with other insecticide seed treated crops, the effect of the insecticide diminished a few weeks after planting. 

Sunflower rust was found in a field in western Bottineau County.  Orange circular pustules were observed on cotyledons and on young leaves.  Early infections are of particular concern and advance rapidly with daytime temperatures in the 80’s and/or night time temperatures in the 70’s.   

For more information see:


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