By: Wendy McDonald – MPSG Production Agronomist – West
Pulse and Soybean Crop Update for Western Manitoba field conditions up to August 1, 2026
Wednesday, July 22
I visited a soybean field near Laurier with an agronomist and the farmer. This soybean field had plants that seemed to be at very different heights and shades of green, without a distinct or repeating pattern through out the field. It did seem a little better in some of the wheels tracks.
Some plants were tall with dark green leaves, and some plants were short with pale , lime green leaves. Interestingly, both plants seemed to have a similar number of flowers at the time and the difference was the length between the internodes were quite a bit further apart on the taller plant and the smaller plants seemed to have more branches.
Very strange that when we looked at the roots, both plants had very few nodules and certainly not close to the 10 functioning nodules per plant that studies show we would need to reach maximum yield. This was a newly rented field 2 years ago. It was wheat last year that did yield about 65 bushels/ acre and the stand had been fairly even. There was no fall soil testing done and P and K was applied in a fall band. This field had never grown soybeans ever before, so the farmer used liquid inoculant and seed treatment on the seed and dry inoculant in the seed row. He actually turned up the rate of dry inoculant to be sure he had enough and essentially these soybeans were triple inoculated but yet were not producing nodules. In the above picture, the tall plant had 1 nodule and some decent lateral roots, and the short plant had no nodules. Both plants had roots that were white and healthy.
This short plant had nicer green leaves than some (you are seeing the bottom of the leaves in this picture) and when looking at the very deep and exploring roots we found a functioning nodule very far away from the crown of the plant. It was really searching for nutrients in this sandier soil. This field experienced no standing water, but did have a few heavy shots of rain (over 2 inches each time). The field across the highway had standing water, was seeded the same day with a different liquid inoculant but same dry rate, and it had been soybeans in the past. It looked great.
This is the colour difference of the top newest leaves in the dark green compared to pale green and short plants. Nitrogen is mobile in the plant and will move from older lower leaves to the newest upper growth. One of the possible reasons that we were seeing not many nodules forming after a triple inoculation (even if the liquid on the seed died, the dry inoculant should have still been okay and helped nodulation) could be that the residual nitrogen level was so high in this field that the nodules just didn’t bother to form when the plant decided it had access to enough nitrogen in the soil early on. Then the rain moved that nitrogen further down into the soil profile, and only the roots that were able to explore deeply were able to access that nitrogen again, and in some plants, even form a nodule or two far away from the crown by using native bacteria. The organic matter could be mineralizing nitrogen now that the tall , green plants were using and organic matter can be variable across a field and some parts of this field could be low in organic matter too.
In some of the strong winds, soil erosion could have moved nitrogen, organic matter, or even rhizobia.
At the beginning of flowering, if digging the roots and counting nodules shows that you don’t quite have close enough to 10 functioning nodules, a rescue application of 50 lbs/ acre of nitrogen may be considered.
Sometimes I can tell a lot about you by where I can find your soybean’s nodules. If most of the nodules are near the crown of the soybean plant, that is a hint that you used liquid on the seed, if more of the nodules are just a bit further below the crown, that is likely from dry granular inoculant. If nodules are really far away on lateral roots that means naturally occuring bacteria were used to make the nodules.
Decreased nodulation can also be caused by low or high pH, or waterlogged soils but that was not the case here.
A nearby soybean field looked very beautiful, tall, and green.
It had great, functioning nodules in abundance at the crown and the lateral roots.
Pods were nicely forming.
Another soybean field I went to had some strange symptoms in the south west part of the field.
A picture of the puckering in the leaves and tips turning white and curling inward.
This is likely drift or volatilization and settling (sometimes from miles away) of a group 4 chemical in a micro dose that has caused this puckering, curling and white tips. The plants should out grow this and it should not cause any yield loss.
Leaf puckering but having no white leaf tips can sometimes be caused by extreme changes in temperature and is called rapid growth syndrome which can also look like someone took the leaf at the stem and at the tip of the leaf and pulled in opposite directions stretching the leaf out so is becomes narrow and distorted. It happens when cells elongate super fast and the inner parts of the leaf grow faster than the edges and the veins do.
Thursday, July 23
University of Manitoba Plant Science For Manitoba Crops field day in Carman.
For the door prize draw, they displayed a dry bean root in a jar (this guy only has a few little nodules). Dry beans are know to be poor nitrogen fixers, but Manitoba research is looking at inoculants that may help in certain areas.
Then, attendees were encouraged to guess how many dry bean plants were actually in this pile of dry bean roots, from the plots where they had counted nodules and evaluated for nodule performance. What’s your guess?
Cassandra Thachuk – MPSG Research Project Manager, joined Terry, Jared, and I as we happily listened to Brodie Erb, technical staff that helps Applied soybean and pulse agronomy and cropping systems Agronomist in Residence Kristen MacMillan with her field trials, talk about the MPSG funded aphanomyces suppression research in the multiple year pulse intensity crop rotation study that has been on -going.
The 2026 soybeans in the 5 year rotation.
2025 was oats. 2024 was canola. 2023 was peas. 2022 was wheat.
The 2026 peas in the 7 year crop rotation.
2025 was wheat. 2024 was canola. 2023 was wheat. 2022 was soybean. 2021 was oats. 2020 was canola.
Another stop on the tour was showing the practical applications of drones in precision agriculture, as they demonstrated this drone could spot spray in the pea crop behind it. It could do a patch as small as 10 meters x 10 meters.
The answer to the question of how many dry bean plants are in the pile of roots is 961!
North of Elm Creek this soybean field has recovered nicely. It had standing water, eroded silt and transported stubble in this corner of the field in June.
At the intersection of the Carman highway and #1, this farmer was combining a forage grass for seed!
Sunday, July 26
Drowned out spots clearly showing up now, in otherwise very nice peas west of Grandview.
Dry beans in Melita, with clean leaves and podding nicely. Too bad about the healthy kochia too.
Black beans in Melita also podding and flowering nicely.
Melita pea variety trials are showing maturity differences.
In Melita, the yellow lupins are advancing and starting to fill pods. It is interesting how clearly you can tell how many seeds per pod there will be.
The lupins struggled slowly in the cool weather and storms early this spring. They are shorter than the peas in the guard plot.
These are the white lupins.
Melita soybean variety trials look very tall and lush.
Soybeans on the way to Waskada, you can tell where the water sat. There are still plants there but they are yellow and stunted.
Look these peas loaded with pods near Waskada, impressive height and standing well.
Apparently, this moose also thinks the peas taste yummy and like me is happy to follow the sprayer tracks in the field.
Tuesday, July 28
Here we are feeling the heat and looking at the soil pit in a soybean field during the 2026 On Farm Research tour, held near Dauphin, at MPSG Director Ernie Sirski’s farm. Ernie and Jan celebrated their 50th wedding anniversary a few days ago.
Chris our MPSG On Farm Network Agronomist spoke about double compared single inoculation trials and their results. I chatted about fungicide application in soybeans and that 71 On Farm Network trials have shown us that fungicide applications in soybeans for white mould only increased yield 15% of the time compared to untreated. The increased yield benfit out weighed the cost of fungicide and application in only 8% of those 71 field scale replicated trials that used farmer’s equipment, conducted over the last 12 years.
A smokey evening and setting sun on this beauty of a soybean crop near Toutes Aide is showing that even though soybeans can handle standing water, if the water stands long enough the soybean plants in those areas will die.
Wednesday, July 29
Terry and I spoke about 2026 production challenges in soybeans at the Sevita Soybean Summit near Bagot.
The crowd of farmers and agronomists drank lots of water and asked great questions.
Then, I dashed off to the Jeffries Seeds tour west of Glenboro. I spoke a bit about nodulation in dry beans and the Manitoba inoculant research that was being done. Farmers in this area had noticed that fields that had previously grown dry beans had fantastic and impressive nodulation compared to virgin uninoculated dry bean fields. We chatted about adjusting nitrogen dry bean rates in the future by evaluating the success of 2026’s nodulation. Also talked a little about fungicide applications in soybeans.
Good looking soybeans here too.
Pinto beans are also looking great.
Nice to see Juno and Fabelle faba beans side by side.
Friday, July 31
Finished the month with a very informative and interesting trip to Fargo, ND to learn about our southern neighbour’s dry bean and soybean breeding, and soybean crush plants. I’m standing in front of the NDSU and Dr. Carrie Dotty’s soybean breeding plots with almost 700 soybean lines here, with the Casselton Soybean Crush plant in the background.