Pathogen Seed Testing for Pulse Crops

Managing pulse crop disease in the 2025 growing season starts now, by getting your seed tested and coming up with a game plan for seed treatment. Ascochyta pathogens, which cause disease in lentil, pea and chickpea, can survive on the seed and then infect the seedling as it germinates. Other seed-borne pathogens, like Fusarium and Botrytis, can cause seed rot or seedling death (damping-off). Pea Seed-borne Mosaic Virus can be transmitted via seed and, outside of selecting resistant varieties, can really only be prevented by planting clean seed.

The Montana State Seed lab in collaboration with the Pulse Crops Diagnostic Lab offers unique and comprehensive testing for seed- borne diseases in addition to traditional germination and purity testing services. The Ascochyta Plus test will cover most of your bases and is $180/sample. If you are concerned about Pea Seed-borne Mosaic Virus then the Smart-V package can be selected which includes testing for that pathogen.

Test results can take 7-10 days, so sending in your seed now will give you time to plan ahead. When you receive your results there are some thresholds established for certain pathogens that can help guide decision making. Your personal tolerance for disease may be more or less than these thresholds. The table below represents guidelines generated by the Canadian Ministry of Agriculture for tolerances of seed-borne diseases of pulse crops. Fungicide seed treatment is recommended for seed-borne Ascochyta, Botrytis and Fusarium for seed lots that exceed the thresholds. In cases where the recommendation is to not use that seed, this is because of the high rate of seed to seedling transmission of the disease and how damaging it can be to the crop.

Seed applied fungicides are not all the same when it comes to protecting your crop against seed-borne disease. Some products lack active ingredients that provide protection against Ascochyta for example. Remember that you are also using a seed treatment to prevent seed rot and seedling blight caused by pathogens in the soil and the active ingredients will need to provide protection against those as well.

 

Crop	Pathogen	Threshold	Action If Over Threshold
Field Pea	Ascochyta	10% on seed	Use seed treatment
Lentils	Ascochyta	5%   10%	Use seed treatment Do not use seed
Chickpea	Ascochyta	>0.3%	Do not use seed
Field pea, Chickpea or Lentil	Botrytis or Fusarium	10%	Use seed treatment

 
Instructions for how to submit a seed sample can be found on the Montana State Seed Lab website. If you have any questions about submitting a sample, test results or selection of an appropriate seed treatment product feel free to reach out.
 
 
Dr. Audrey Kalil, Agronomist/Outreach Coordinator
 
 

Soybean Variety Selection

 
Two frequent questions customers have been asking lately on soybean variety selection are 1) the relationship between yield and maturity group and 2) variety selection based on soil type. Maturity group can influence soybean yield and other traits because soybean development is driven by temperature and photoperiod (the interval during a 24-hour period when the plant is exposed to light), which changes according to latitude and growing region. Shorter days and warm temperatures control soybean flowering, the onset of the reproductive phase of growth. If you choose to grow a variety further north than its designated maturity range, vegetative growth is longer, and flowering is delayed because of the longer days and cooler temperatures. Although you could potentially have higher yield with a later maturing variety, an early killing frost may result in reduced crop yield and quality.
 
Poorly drained or heavy textured soils lead to problems with Phytophthora root rot caused by the soil borne fungus Phytophthora sojae. So far, we do not have documented issues with this pathogen in our area, but you can select a variety with good disease tolerance and seed treatments are available (see attached). As with all soil pathogens, the risk will increase with the frequency of soybean pro- duction in a field. Soybeans also struggle to emerge through soil that is crusted or compacted, which is generally more of a problem on heavy ground. Managing compaction in those fields will improve soybean emergence.
 
The Winfield United website has some great resources to help with variety selection. They conduct trials called “Answer Plots” around their territory and this information can be found online. The Answer plots that have “fine soils” and are the most like our clay soils in the Yellowstone Valley were in Casselton, ND and Watertown, SD. Listed in the table below are top performing Croplan varieties at each site, Casselton was the only site to grow 0.4 maturity. At these locations there was not a consistent trend in late maturing varieties having better yields in the Northern U.S.
 

Relative Maturity		Casselton, ND	Watertown, SD
	Variety	Yields (bu/ac)
0.4	CP0329E	67.0	-
0.4	CP0244XF	66.5	-
0.4	CP0440XF	64.2	-
0.8	CP0820E	65.0	63.2
0.8	CP0740XF	64.7	62.5
0.8	CP0940 XF	62.1	67.0
1.2	CP1240XF	67.4	60.4
1.2	CP1121E	65.2	-
1.2	CP1242XF	64.2	-
1.2	CP1130 E	62.6	58.3

 
Early maturing 00 soybeans have plenty of yield potential. You can see that in the regional 2024 soybean Answer Plot data (attached). The highest yields in the whole region in 2024 came from early beans (ex. CP00840XF at 80 bu./ac). The 00 group in the Regional Answer Plots had the highest average yield (60.9 bu.) compared to 04 group (56.2 bu.) and 08 group (56.9 bu.) groups in 2024. When you compare locations that had the same varieties between 00 and 04 groups, then you can see the maturity difference. Five locations - Hannaford, Harvey, Larimore, Washburn and Warren all had the 00 and 04 groups in each location. At these locations, the 04 group averaged 61.6 bushels and the 00 group averaged 58.3 bushels, a 3.3 bushel advantage to the longer maturing beans. So there is definitely a maturity advantage at some locations in 2024, but there is also a maturity risk on early frost in the fall.
 
NDSU has conducted soybean variety trials at the Nesson Valley Irrigated Research farm (2018 & 2021) and at off-station variety trials in Trenton (2021 & 2022) (trial data attached). The Nesson Valley site is characterized by a fine sandy loam and the Trenton location was a silty clay. In the table below, yield was averaged across multiple soybean varieties and study years by maturity group separately by location. At the Nesson site the later maturity varieties trended higher in yield, whereas the pattern at the Trenton site was inconsistent.
There may have been other factors that were impacting yield at that location.
 

Yield (bu./ac)
Maturity	Nesson Valley	Trenton
0.3	62.7	59.2
0.2	58.7	56.0
0.08	54.3	50.5
0.09	54.2	58.0

 
 
There are many characteristics outside of maturity rating to consider when selecting a soybean variety including IDC rating, disease resistance, herbicide resistance, and stress tolerance. We never know what the weather will bring in terms of rain, heat, disease, or frost so planting more than one variety with different maturity groups may be a way to manage your risk when trying out some new genetics.

Agronomics are just as important as selecting the right variety, particularly ensuring adequate stand establishment. Last year many soybean fields in ND and MN, including the Williston area, saw problems with Rhizoctonia seed rot and seedling blight and that can easily be prevented by using an effective seed treat.
 
Julia Seiller, Agronomist Horizon Resources Fairview
 
Dr. Audrey Kalil, Agronomist/Outreach Coordinator Horizon Resources Williston
 
 

Looking at Data Critically

The lull of winter is a great time to be scouring over data to decide if there are new practices, products, or varieties to be implemented on the farm for the coming season. And let’s face it, you get bombarded with new data all the time promoting a new product someone wants you to try. But what can you trust to be true, and when do you know it’s something to steer clear from? Here’s how I try to peel back the layers to know what good data is, and what is just, well….BS.
 

What are your goals?

First think about why you want to try something new. For a new practice, maybe you are trying to improve soil health. In that case yield may or may not respond but that isn’t necessarily your goal in the short term. For pest management products – insecticides, fungicides, or herbicides you want to make sure the insects, diseases or weeds are being controlled. In those cases, disease ratings, insect population or percent weed control is sufficient information for you to determine if something works like it should. Yield may or may not respond to the treatment depending on severity of the problem or if there are other factors that impacted yield.

However, for fertility or other “crop health” products - if yield numbers cannot be produced and all that is shared is how much something changed in a soil or tissue test, how do you even know it is something that can be profitable for you? While we hate to feel like we are missing out on the latest thing, remember, you need to know how much you can improve your yield to calculate if this is something that can provide a return on your investment. Seeing stand counts, tissue test results, and other crop ratings are great as support materials, but shouldn’t replace what the yield difference is for these types of products.
 

Where does the data originate?

Did it come from Montana or North Dakota or was it from a different state? Then ask where it was, our local counties or somewhere like Bozeman or Fargo? Our climate is unique and so will be our crop response. It’s ok to use data from other regions but always keep in mind that they might see positive OR negative responses because of climatic reasons that were unique to that region during that season.
Being able to evaluate multiple sources of data about a product or
practice can help boost the credibility of the claims. For varieties you can check out University variety trial data, do these data confirm what other sources are claiming?

How was this data derived?

Was this a side by side within the same field, comparing field to field, replicated research, was it small plots or field scale planter wide strips, can the one who conducted the research me named? Comparing two separate fields is not considered valid because there are other factors outside of the product or practice that could have influenced yield or other response. Crop rotation, soil, pest pressure, etc. The more
information that can be provided to you, the more you can start to decide for yourself if you can trust the data. If they cannot provide any of this information to you, well I sure hope your BS meter is starting to warn you to steer clear. A one off response is not a reliable indicator of product performance.

Good data comes with stats.

Statistics is a scientific discipline all of its own, and even the experts can disagree on the best way to analyze data, so I won’t belabor this topic. Big picture is that if the data presented to you has some statistics included with a table or a chart (C.V.%, p-values, LSDs) that necessarily means that there was some replication in the trial and that an effort has been made to determine if the differences observed are replicable. Just because it has a C.V.% and LSD does not make it automatically good, but they are needed to determine if the results can be replicated, including on your farm.

Wrapping up

All of this is to say, be critical of what you are doing on your farm. It’s ok to be skeptical of new things and ask questions. The above described are just some ways you can vet out who put some real work into proving what they are selling can improve your crop. We are fortunate to have great Land Grant Institutions, NDSU and MSU, that are working on independently evaluating products and practices, so you don’t have to take on that risk. If you decide to try something out, conduct a trial on your farm to see if you get a response. Replications within the same field with multiple treated and non-treated areas will allow you to determine if it was worth the investment.
 
 
Kyle Okke, Crop Consultant, CCA

 

Upcoming Events

January 21, 2025 Wild World of Weeds Workshop; Fargodome, Fargo, ND or virtually (recording available to those who register)

January 22, 2025 Soil Water Workshop; Fargodome, Fargo, ND or virtually (recording available to those who register).

January 28, 2025 Williston Wheat Show; Grand Hotel, Williston, ND
 
January 28, 2025 Northern Pulse Growers Association Annual Conference; Sleep Inn & Suites Conference Center, Minot, ND

January 29, 2025 Best of the Best in Wheat and Soybean Research Meeting; Grand Hotel, Minot, ND
 

GROW Internship Program—Applications Open

Horizon Resources has launched a paid internship program for High School seniors or college students seeking a career in agronomy. Entitled GROW (Guided Real-World Opportunities in Work), this program is designed for students who want to gain practical experience and will help them launch their career after graduation. We are currently accepting applications for our Fairview, Zahl and Williston locations and students can submit their application through our website. To learn more, listen to the On The Horizon podcast episode where Williston Location Manager, Austin Semenko, and Dr. Audrey Kalil discuss the program and how to apply.