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2020 Small Grains IPM Survey (09/24/20)

The purpose of the IPM (Integrated Pest Management) Survey is to detect the presence and population levels of diseases and insect pests that are common in wheat and barley grown in North Dakota.

The purpose of the IPM (Integrated Pest Management) Survey is to detect the presence and population levels of diseases and insect pests that are common in wheat and barley grown in North Dakota. Nine survey scouts or insect trappers operated out of the Dickinson Research Extension Center, the North Central Research Extension Center (Minot), the Carrington Research Extension Center, the Langdon Research Extension Center, the Williston Research Extension Center and the Fargo Agricultural Experiment Station. The NDSU IPM scouts were:

  • Sean Nichols, central and south central counties, worked out of Carrington REC with Greg Endres
  • Kia Ward, southwest and west central counties, worked out of Dickinson REC with Ryan Buetow
  • Spencer Furniss and Riley Racine, north central counties, worked out of NCREC in Minot with Travis Prochaska
  • Scott Roseth, northwest counties, worked out of Williston REC with Jerry Bergman
  • Marc Michaelson, southeast and east central counties, worked out of NDSU campus, Fargo with Jan Knodel, Andrew Friskop and Sam Markell.
  • Nancy Feil and Traci Murphy, northeast counties, worked out of Langdon REC with Anitha Chirumamilla, Lesley Lubenow and Benson County Extension Office with Scott Knoke

NDSU IPM field scouts surveyed a total ofent.1 707 wheat fields (winter wheat, hard red spring wheat, durum wheat) and 220 barley fields for 18 diseases and 6 insect pests in North Dakota in 2020. The survey was initiated on June 4th and continued through August 13th. Crops were surveyed from the 2-leaf stage (seedling) through ripening stages. IPM survey data/maps provided near real-time pest information to North Dakota producers and others in agriculture to assist with scouting and pest management decision making. Pest maps from the 2020 IPM Survey in North Dakota were uploaded weekly onto the NDSU IPM website. Some of the pest highlights for wheat and barley are summarized below.

Grasshoppers – Grasshoppers were surveyed for in all crops including wheat, barley, soybeans and sunflowers. Adult grasshoppers were observed in 91% of the fields surveyed. This shows an increasing trend in the populations of adult grasshoppers over the last three years: 86% in 2019, 75% in 2018 and only 36% in 2017. The number of adult grasshoppers per 4 sweeps (1 yd2) ranged from 0 to 28 per 4 sweeps. The highest infestations were located in the central and southwest areas of ND.

The warm spring favored grasshopper development and reproduction. The wet conditions in some areas of ND did not seem to negatively impact grasshopper levels. Feeding injury was present on field edges in most fields. However, some fields needed a whole-field treatment.

ent.2.grasshoppers

 

Insect Pests of Small Grains:

Grain aphids were very low and observed in only 3% of the wheat fields and 6% of the barley fields surveyed in North Dakota. Grain aphids were first detected mid-June and populations never developed into damaging levels (85% of stems infested with one or more aphids). In wheat, the percentage of infested stems ranged from 1-12% with an average of 2%. In barley, the percentage of infested stems ranged from 1-6% with an average of 3%.

ent.14 15.banded sunflower moth trapping network

Wheat stem maggot was observed in 22% of wheat fields surveyed in ND and damage ranged from 1-56% of plants with damaged heads (white heads). Wheat fields with >20% damaged heads were observed in northwest (Burke, Divide, McKenzie Counties), and north central (Mountrail County). This was the same area with higher populations in 2019.

ent.5.wheat stem maggot

Wheat stem sawfly was collected with sweep nets in 7% of the wheat fields surveyed during mid-June though late July in 2020. However, wheat stem sawflies were more common and widespread than in 2019. Wheat stem sawflies were most common in the northwest (Burke, Divide, Mountrail Counties); north central (Bottineau, McLean, Renville, Ward Counties) and the whole southwest of North Dakota. Areas with more intense drought would have increased wheat stem sawfly survival for next year.

Cereal leaf beetle was not detected in wheat or barley in 2020. The counties of North Dakota that are known to have cereal leaf beetle are Burke, Divide, McKenzie, Mountrail and Williams counties in northwest; Renville, McHenry and Ward counties in north central; and Cavalier and Nelson counties in northeast.

Barley thrips were low and observed in only 7% of the barley fields surveyed from mid-June through mid-July. The central area of ND reported the highest levels of the barley thrips ranging from 1-4 thrips per stem, which was not economic for 2020. The calculated 2020 economic threshold for barley thrips was an average of >6 thrips per stem for malting barley and >7 barley thrips per stem for feed barley.

ent.6.wheat stem sawfly.barley thrips

Foliar Diseases of Small Grains:

Tan spot and bacterial leaf streak were the most common foliar diseases of wheat in 2020. Tan spot was recorded in 21% of the fields and the highest levels were reported in the Western half of the state (Figure 1, page 4). Bacterial leaf streak is a disease that is most commonly observed after flag leaf emergence. In fields scouted at flag leaf stage or later, bacterial leaf streak was found in 27% of the fields. Also, higher levels of bacterial leaf streak were recorded in the Eastern half of the state (Figure 2, page 4). For barley, bacterial leaf streak, spot blotch and net blotch were the most commonly identified diseases. Bacterial leaf streak was recorded in 22% of fields (at flag leaf stage or later), spot blotch was recorded in 7% of the fields and net blotch was recorded in 5% of the fields.

Fusarium head blight (scab) risk was moderate to high for some areas of the state this past growing season. However, it appears most of the early seeded small grain fields “escaped” the risk window resulting in low levels of scab being documented. The NDSU IPM scouts visited 248 wheat fields after the flowering stages of wheat and documented scab in 8% of the fields (Figure 3, page 5). In fields where scab was found, severity was low. For barley, scouts visited 110 fields that were at heading growth stages or later and scab was recorded in 9% of the fields.

ent.7 8.wheat tan spot and wheat bacterial leaf streak

ent.9.wheat scab field severity index

 

Janet J. Knodel                                                                                                  Andrew Friskop

Extension Entomologist                                                                                 Extension Plant Pathology, Cereal Crops

 

Patrick Beauzay                                                                                                Sam Markell

State IPM Coordinator and Research Specialist                                    Extension Plant Pathologist, Broad-leaf Crops

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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