Iron-deficiency chlorosis (IDC) is common in North Dakota and reduces yield. The best way to reduce the yield losses associated with IDC is to select a tolerant cultivar. Growers need data that compares varieties from different private companies in the same environments using the same experimental method. This proposal would permit approximately 350 different GMO company varieties and non-GMO varieties to be evaluated for IDC tolerance. An additional 100 NDSU
breeding lines would be evaluated. All private company varieties that have been entered into the Langdon Research and Extension Center (REC), Carrington REC, Minot REC, and Fargo Main Station yield trials will be evaluated for visual ratings of IDC at multiple field locations. Visual yellowing that is caused by IDC has been shown to be closely correlated to yield
for fields that have IDC. This data will provide an independent confirmation of the IDC tolerance of company products and enable growers to compare varieties from different companies. This proposal will aid growers in selection of tolerant cultivars to increase yield on fields that have a past history of IDC.

The objective is to screen all private company varieties that have been entered into the Langdon Research and Extension Center (REC), Carrington REC, Minot REC, Williston REC and Fargo Main Station yield trials for visual ratings of IDC at multiple field locations with a past history of IDC symptoms. A second objective is to provide visual IDC screening of approximately 100 advanced NDSU breeding lines. Soybean growers need information to aid them in comparing
varieties from many different companies for iron-deficiency chlorosis (IDC) in side-by-side comparisons. This data provides unbiased information that enables growers to choose the best variety for their IDC prone fields.

Growers will be provided with data that enables them to identify the best varieties for those fields that are susceptible to IDC. Data will be analyzed and reported in the NDSU bulletin entitled ‘North Dakota Soybean Performance (A -843)’ and posted online at https://www.ag.ndsu.edu/varietytrials/soybean.

Updated January 5, 2024:
Visual rating for iron-deficiency chlorosis (2023) - Miranda

Objectives of the research: The objective is to screen all private company varieties that have been entered into the Langdon Research and Extension Center (REC), Carrington REC, Minot REC, Williston REC and Fargo Main Station yield trials for visual ratings of IDC at multiple field locations with a past history of IDC symptoms. A second objective is to provide visual IDC screening of approximately 100 advanced NDSU breeding lines. Soybean growers need information to aid them in comparing varieties from many different companies for iron-deficiency chlorosis (IDC) in side-by-side comparisons. This data provides unbiased information that enables growers to choose the best variety for their IDC prone fields.

Deliverables: Growers will be provided with data that enables them to identify the best varieties for those fields that are susceptible to IDC. Data will be analyzed and reported in the NDSU bulletin entitled North Dakota Soybean Performance (A -843) and posted online at https://vt.ag.ndsu.edu/list/soy.

Milestones: Milestones include collection, experimental design, packaging, and planting of all private company seed. This is not a small task and is an accomplishment to complete. Visual rating of IDC symptoms occurs from end of June through July. Results are reported in August.

Key performance indicators: Collection of successful data is a major indicator. This relies not only on field symptoms but on field maintenance and diligent note taking of private company and NDSU lines.

Completed work: Hill plots were planted at three locations with a past history of IDC. One location was lost due to lack of IDC symptoms. Iron-deficiency chlorosis was observed at the two other sites and IDC scores were taken at 2 different time points, two weeks apart. One hundred and ninety three Enlist and Xtend soybean varieties were evaluated for visual symptoms of IDC. This is a slight decrease in entries from 2022. Twenty one Liberty Link or non-GMO cultivars were evaluated for IDC which is a slight decrease from 2022. Ninety eight experimental lines or released cultivars that had been developed at NDSU were evaluated for visual IDC score. Each genotype was evaluated at two different growth stages on a 1-5 scale. At each site there were four replicates. Iron-deficiency chlorosis was evaluated at about the V3-V4 stage and again at the R1-R2 stage. The data was averaged across both of these rating growth stages. The data was of good quality at two locations. The results were published online https://vt.ag.ndsu.edu/list/soy and will be printed in the Soybean Variety Trials bulletin A-843.

This project is completed for the 2023 growing season. We are considering charging a fee for this project in the 2024 season. The electronic application for the 2024 growing season will be posted in January 2024. Seed will be collected from companies in April 2024 and packaged for planting. Planting will occur in early June 2024.

View uploaded report

Updated July 1, 2024:

View uploaded report

Executive Summary

a. Research project title, Principal and Co-Investigators

Title: Visual Ratings for Iron Deficiency Chlorosis
Principal Investigator: Carrie Miranda, PhD

b. Why the Research is Important to North Dakota Soybean Farmers

This data will provide an independent confirmation of the IDC tolerance of company products and enable growers to compare varieties from many different companies with all of those varieties evaluated at the same locations. Comparing soybean varieties from different companies requires that the varieties of all companies are evaluated, averaged across the same fields, otherwise a fair comparison is not possible. This data enables growers to increase their yield on their IDC prone fields because those varieties with the least amount of yellow IDC symptoms will yield the best on those fields that have that problem.

c. Research Conducted: (brief description of materials and method)

Private companies are able to submit the newest varieties for testing by the third party NDSU. 214 varieties were tested in 2023 and 181 varieties will be tested in 2024. In 2023, these lines were grown in three IDC affected fields and in 2024 that is increased to four locations. Lines are grown and scored as advised by Dr. Jay Goos. Scores are collected, analyzed, and published online by August every year. They are also published in the A-843 report in print in December every year.

d. Findings of the Research

IDC symptoms have been more severe in 2022 and 2023 than in previous years. We are increasing the number of locations in order to assess IDC tolerance of these lines across different levels of severity. We are also increasing the number of locations in case of loss of data due to herbicide drift, no symptoms available, hail, etc. Many growers rely on these publications and we want to ensure high quality data every year.

e. Benefits and Recommendation to North Dakota Soybean Farmers and the Industry

The iron deficiency chlorosis (IDC) trial provided useful and necessary data to North Dakota farmers to aid their decision process for selecting the most appropriate soybean variety for their fields. This project also allows for testing of NDSU experimental lines, which allows the breeding program to make thoughtful selections for lines based on IDC resistance which is an important trait in eastern North Dakota. These trials will continue on, self supported by private company entry fees in 2025 and onward.

This data will provide an independent confirmation of the IDC tolerance of company products and enable growers to compare varieties from many different companies with all of those varieties evaluated at the same locations. Comparing soybean varieties from different companies requires that the varieties of all companies are evaluated, averaged across the same fields, otherwise a fair comparison is not possible. This data enables growers to increase their
yield on their IDC prone fields because those varieties with the least amount of yellow IDC symptoms will yield the best on those fields that have that problem.