Soybean School: How weather impacts maturity

Soybean School on RealAgriculture.com is brought to you by Pride Seeds, BASF Canada, and Syngenta Canada. Bernard Tobin here at Canada's Outdoor Farm Show, catching up with Horst Bonner, OMAFRA Soybean Specialist. Horst, how's it going? Excellent. Nice to see you. It's great to see you and be here at the Outdoor Farm Show this week. I want to talk about something a lot of farmers are talking about, right? Soybean maturity. We're seeing leaf drop, we're seeing uneven maturity, we're seeing some yellowing. Whereabouts are we from a maturity perspective? So we're standing in a field here, this is one of our trial areas, and when we compare to other years, we're about 10 to 12 days behind normal in terms of where the beans are for maturity. So we're definitely behind. Now as you know, soybeans are pretty smart with the photoperiod effect, starting to shut down and then shutting down pretty quickly as the days shorten. Corn, I think, is the bigger question in terms of what it will mean for harvest stability and moisture and all that, but the beans, yeah, 10 to 12 days. So Horst, let's take a look at this field that we're in here right now, I mean a really interesting field. We've got a lot of leaf drop right here, over on this side, we've got a lot of leaves hanging on, green, yellow leaves, right here in the same field. Same variety, planted same day, and yet not a perfectly even maturity, right? And that's actually what we want, we want them all to mature at the same time. Sometimes there is a nutrient component in terms of the beans that aren't finishing, don't have all the nutrients, and don't have as many pods on them. Here, interestingly enough, this is a very simple explanation, and you see it across a lot of the southwest this year, different timing for emergence. They just came up a little later because they were too dry, you know, a week later, and now you see it in the fall, they didn't all come up on the same day, and so it's simply just an emergence difference in the spring. What's our path forward here? I mean, you know, you mentioned obviously a little bit more worry about corn, but what needs to happen in the next month for us to get to where we need to be? So I think, of course, the main risk is still an early frost, right? And so typically when beans start to really yellow like the ones we're in here, we're at the R6 growth stage, which is the full seed. So the seed inside the pod is reaching the full capacity of that pod. That's called the green seed stage or R6, right? Once you hit that, we can take some frost and still have a pretty normal yield. Now that's not physiological maturity. We don't reach that until R7 when one of the pods on the main stem turns a mature color, usually brown, right? So the point is, we've got from here this field, R6, now it was already yellowing last week, so we're into R6 a bit. But typically it's about 14 days to reach physiological maturity, okay, R7. And then it's about another 10 days to reach R8 or full maturity. So beginning maturity, R7, full maturity, R8, another 10 days. But then we're still not really dry enough for harvest, so that's about another five days. So when can we combine? Yeah, yeah, yeah. So you go and add those up here for me. So you add those numbers up and you get to four weeks, right? So when the beans start to yellow, we're talking about four weeks typically. Now it depends on the variety, right, of that maturity thing that we've talked about before in terms of what maturity grouping the soybean is. Because of course, the longer the maturity of the variety, all those phases, all the R phases are a little bit longer. So that four weeks that I just gave you can be as much as five and a half weeks if it's a real long season bean. So middle of September, you mentioned, middle of October, I think we're going to have only very short season beans really that are ready to go by Thanksgiving. We have heard of just a few fields off in the province, very, very few extremely short season beans planted quite early, but the majority of the crop is going to be late this year. Hey, let's talk about yield. I mean, we've got this long season, long growing season, grain fill, might we be looking at some better yields? So there's huge variability this year, largely dependent on whether you had too much rain, right? We did actually have drowned out areas and then of course there's white mold that develops. So the range is going to be tremendous. In our plots this year, literally I have beans that I think will only do 20 bushels and I have beans that I'm quite confident will be over a hundred bushels this year. But to your point, this kind of cool, wetter August and now delayed maturity, I think is actually a good thing for soybeans in terms of bigger seed size. Like we're not changing the number of pods now, but bigger seed size. So stretching it out a bit into fall from a soybean perspective is not a bad thing. Final question for you. And you and I have talked about this many times over the years, we've started to go for longer maturities, stretching those maturities. And for a yield perspective, you mentioned we're 12 days behind, what have we learned this year about that push for longer day beans? You're so right, we're trying to update that maturity map for Ontario to give the best recommendation of what is adapted for your area. And this is a year again that kind of checks that constant push to saying we can grow longer longer day beans. So this is part of the data set. Now, the other neat thing about beans, though, but if you look at this picture here, this is this is just a perfect example of how light in the fall, as they shorten, actually finish up beans. Because you can see right there to the line where the light shone from that security post, the beans didn't mature properly. So the point of that picture is, boy, we need those shortened up days in the fall. And all of a sudden, beans, they finish up pretty quick. Horst, thank you for stopping by. Great insights. Let's hopefully we get some heat, we get some sunlight and we finish up some soybeans and get on the corn. Oh, we'll get the job done. Very good. Thank you.