2021 IPM CROP Survey – Wheat and Barley (09/23/21)
The IPM (Integrated Pest Management) Crop Survey helps ND farmers, crop
consultants, and ag audiences stay up-to-date on important diseases and insect pests of wheat, barley, soybean and sunflower grown in North Dakota. Eight IPM scouts and 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:
- Carrie Nichols, central and south-central counties, worked out of Carrington REC with Greg Endres
- Iris Dukart, southwest and west central counties, worked out of Dickinson REC with Ryan Buetow
- Alexius Holter and Riley Racine, north central counties, worked out of NCREC in Minot with Travis Prochaska and Leo Bortolon
- Scott Roseth, northwest counties, worked out of Williston REC with Claire Keene
- Tommy Crompton, southeast and east central counties, worked out of NDSU campus, Fargo with Jan Knodel, Andrew Friskop and Sam Markell
- Nancy Feil and Jolena Lowery, northeast counties, worked out of Langdon REC with Anitha Chirumamilla, and Benson County Extension Office with Scott Knoke.
NDSU IPM scouts surveyed a total of 678 wheat fields (winter wheat, hard red spring wheat, durum wheat) and 119 barley fields for 18 diseases and 6 insect pests in North Dakota. The survey started on June 1st 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 farmers and others in agriculture to assist with scouting and pest management decision making. Pest maps from the 2021 IPM Crop Survey in North Dakota were uploaded weekly onto the NDSU IPM website. Please note that the website address will be changing in the near future. 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. IPM data showed an increasing trend in the populations of adult grasshoppers over the last four years: 91% in 2020, 86% in 2019, 75% in 2018 and only 36% in 2017. The hot, dry summer increased grasshopper development and reproduction. The number of adult grasshoppers per 4 sweeps (1 yd2) ranged from 0 to 32 in 2021. The highest densities of grasshoppers were observed in the northeastern North Dakota. Defoliation was common on field edges in most fields throughout the state. Whole-field treatments were necessary in areas where grasshopper populations were high (see yellow and red areas on grasshopper map).
Insect Pests of Small Grains:
Grain aphids were higher in 2021 than 2020, and observed in 11% of the wheat fields and 6% of the barley fields surveyed in North Dakota. Grain aphids were first detected in late June. The economic threshold is 85% of stems infested with one or more aphids through heading. In wheat, the percentage of infested stems ranged from 1-100% with an average of 17%. In barley, the percentage of infested stems ranged from 2-24% with an average of 7%. In the southeast and east central areas of North Dakota, grain aphids continued to increase past the known susceptible stage (end of heading), and were commonly observed on wheat heads at high densities of >100 aphids per head. Farmers and crop consultants expressed concern about these high numbers on heads and its potential impact on yield.
Wheat stem maggot was observed in 15% of wheat fields surveyed in ND and damaged white heads ranged from 1-24% of plants sampled. In 2021, wheat fields with >20% damaged heads were observed in northeast (Nelson, Walsh counties).
Wheat stem sawfly declined from 2020 and was collected with sweep nets in only 2% of the wheat fields surveyed during mid-June though early July in 2021. Wheat stem sawflies were most common in the northwest (Burke, Divide, Mountrail, Williams Counties); and north central (Bottineau County) areas. Areas with more intense drought could have increased wheat stem sawfly survival for next year.
Cereal leaf beetle was not detected in wheat or barley in 2021. 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 3 barley fields in Trail, Foster and McLean Counties.
Foliar Diseases of Wheat and Barley:
Disease incidence in 2021 wheat fields was extremely low this year. The low amount of rain, low humidity, and higher than average temperatures in June drastically reduced disease risk. Tan spot was detected in 4% of the fields and bacterial leaf streak was detected in less than 1% of the fields. Leaf rust was only reported from NDSU research plots with no reports from agronomic fields. Foliar disease was also very low in barley fields this year. Fusarium head blight (scab) risk was low in 2021. Less than 1% of the fields had Fusarium head blight, and in those fields, low index values (field severity) were reported. A significant amount of the small grain crop started to head in mid-June at a time during hot temperatures and low humidity
Extension Entomologist Extension Plant Pathology, Cereal Crops
State IPM Coordinator and Research Specialist Extension Plant Pathologist, Broad-leaf Crops