2.9 - Post-Plant 2025 Rice Round Table with UCCE Rice

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The UCCE Rice group discussed various agricultural topics including no-till rice field demonstrations, pest management challenges, and new tools for detecting tadpole shrimp, followed by updates on ongoing research projects and planting trials in the 2025 rice season.

Upcoming Events

• Rice Production Workshop - July 23-24, 2025, Davis, CA - an introductory course in rice production to cover the basics of rice farming
• Weedy Rice Workshop - August 5, 2025, 10:00 AM - 1:15 PM, Roberts-Union Farm Center, 4925 Howard Rd, Stockton, CA 95206
• Rice Field Day - August 27, 2025, Rice Experiment Station, Biggs, CA

Other Resources

UC Rice Blog

UC Agronomy - Rice

Rice Briefs (Colusa/Yolo)

Rice Notes (Yuba-Sutter)

Rice Leaf (Butte/Glenn)

Rice in the Delta

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Transcript

Sarah Marsh Janish: 0:00

Hello and welcome to Thoughts on Rice, a podcast hosted by the University of California Cooperative Extension Rice Advisors. I'm one of your hosts, Sarah Marchionish, and I'm a rice farm advisor for Colusa and Yolo counties.

Whitney Brim-Deforest: 0:24

I'm Whitney from the forest. I'm the Cooperative Extension Rice Advisor for Sutter, Yuba, Placer, and Sacramento counties.

Luis Espino: 0:31

My name is Luis Espino. I'm the Rice Farming Systems Advisor for Butte and Glynn

Michelle Leinfelder-Miles: 0:38

counties. I'm Michelle Leinfelder-Miles. I'm a farm advisor in the Delta region. I work on all sorts of field crops, grains and forages, but one of those is rice. And the counties that I cover are San Joaquin, Sacramento, Yolo-Solano, and Contra Costa counties.

Sarah Marsh Janish: 0:57

Together, the UCCE Rice Farm Advisors seek to provide relevant topical research-backed information relating to California rice production. Welcome back to Thoughts on Rice, and I'd just like to thank you all in advance for sticking with us through this hiatus we had recently. As I'm sure everybody in the rice industry understands, it was planting season, and that pretty much takes precedence over anything else. But Kind of to remedy that, we've actually got a great group of people on here today, a pretty collaborative effort of rice specialists and rice advisors getting together to talk about kind of a rice roundtable, what we're working on this summer, some of our recent field days, and then what some of the farm calls we've been getting look like. So to start off, I think we're going to start with a round of introductions just to match names with voices as it were. But again, my name is Sarah Marchionish, rice farm advisor for Colusa YOLO.

Luis Espino: 1:58

Luis Espino, Rice Farm Advisor for Butte and Glynn Counties.

Whitney Brim-Deforest: 2:03

I'm Whitney Brim-DeForest. I'm the Rice Advisor in Sutter, Yuba, Placer, and Sacramento.

Bruce Linquist: 2:08

Hi, I'm Bruce Lindquist. I'm the UC Rice Specialist based in Davis.

Ian Grettenberger: 2:13

Ian Grettenberger, Cooperative Extension Specialist based out of Davis, working on entomology and arthropods.

Sarah Marsh Janish: 2:20

Thanks for making the time, guys. planting system of planting no-till drilled rice. And so I'd love to hear your guys' perspectives of that event, because for me, being in the audience, it seemed like, well, one, it was very well attended. Maybe the weather had a little bit to do with that. It was a lovely day. But also, there seemed to be a lot of interest in this new planting system. Would you say that that seemed accurate?

Bruce Linquist: 3:04

Yeah, I believe there was a lot of interest as demonstrated by a very good and interested crowd. I really appreciated just the insights of Josh and Kim. You know, we're looking at stuff a lot just from a research perspective. I really appreciated what they had to say, kind of how it fits on their farms. And, you know, it's a bit of a reality check on the system too. I think they both saw some promise on it. But I like their perspective that, you know, planting time, that is an issue. It takes a while to plant these fields. And so, you know, if that comes at a really busy time of year, that could be a tough thing to accomplish. It requires wider equipment. And, you know, just the economics, I think, of it. I think Josh said he's probably going to come close to breaking even. He didn't see... He was hoping maybe to get back by with some cheaper herbicides or fewer herbicides. He didn't realize that this year. So I really appreciated that kind of perspective. And I think it kind of points to the need for some economic analysis on this.

Sarah Marsh Janish: 4:17

Yeah, I think that's a great point, Bruce. And yeah, just for those who weren't there, we had the great opportunity of having two growers who have actually done this in their field on a field setting in two very different microclimates and geographic areas, different types of soil. And I think we did see that variation. Would you agree, Bruce?

Bruce Linquist: 4:36

Yeah. The other thing that really stuck out, we don't research soil. seeding depth, but I think that's a huge component of that system, being able to prepare a field so that you can get that seed in at the right depth. I think that's a really critical thing that stuck out for me. Again, we don't do research on that at the station, but certainly the grower experiences, I think that was a big part of the story between Josh and Kim.

Sarah Marsh Janish: 5:02

Now, Whitney, I know you got this question a lot, especially this year. But since Bruce touched on Josh's herbicide options, do you think you could give us just a quick briefer on the talk you gave about the options for herbicides in terms of no-till drill-seeded rice?

Whitney Brim-Deforest: 5:18

Sure. So one of the big things, and I think Bruce can touch on this as well, but winter weed control is going to be a big issue in these drill seeded systems. Most folks aren't going to be winter flooding because it kind of doesn't work well with the no-till system. And so as a result, we're getting a lot of winter weeds. And I would say the biggest one, biggest problem that we noticed was Italian ryegrass. So that was popping up. I would say I didn't see Josh's field, but I saw it in Kim's field and in our fields at the station. And the problem with Italian ryegrass for folks that aren't familiar with it is that it is very hard to control with herbicides. And so we're very limited on our winter herbicide options. And so it made it so that we basically were not able to control it going into the season. So we planted the rice in some cases like over the ryegrass. And so that caused some issues for, I think, One of the growers, and I think a little bit, we saw our drill seeded up at the experimentation as well. So the ryegrass, I don't know how competitive it is, but I will say that we saw some holes as the season went on, once the field was flooded. So wherever there was ryegrass, there was a hole. So whether that's from competition, I'm not sure, or if it's from simply the rice wasn't able to be planted over the ryegrass. But I think that's going to be the biggest winter weed problem. There were some other ones, but I would rate them a lot less problematic. Ryegrass is really the one I think that's going to be the most problematic for us in this system.

Sarah Marsh Janish: 6:53

Yeah, I think that's a really good perspective because, I mean, especially in the no-till drilled system, you're not getting that tillage that might chop up and destroy your winter weeds. So that's something that's an added factor, right? Right.

Whitney Brim-Deforest: 7:06

Yeah. And I mean, I didn't really touch on the in-season weed control, but Sarah, you and I are working on a drill seeded trial up at the station to try to get some programs together. And then also like the other big issue that we have, I guess, is for pre-emergent herbicide application options. We really only have one right now and that's pendimethalin. And it's a great product, but I mean, There's only one. So it would be nice to be able to rotate with another herbicide. It does provide pretty good control of grasses and sedges, but it's not going to provide control through the season. So it's good early season control, but again, not going to provide control all the way through the season. So I think what Josh was touching on about maybe using the same amount of herbicides or not reducing those herbicides, kind of tracks with what I would guess would happen in these systems. So you'll need a pre-emergent and then a follow-up at like the two to four leaf stage before you put on your permanent flood. And then maybe something after the permanent flood, which sounds like that's what Josh ended up having to do. So we're having to apply a winter herbicide program plus, you know, between two to three herbicide applications during the season. And then another thing I mentioned at the field day is that we have We have, you know, pendimethalin is an added option, which is a new mode of action for us, but we're actually reducing the number, the total number of modes of action that we have available because we're not able to use granular herbicides at the beginning of the season. So I think it's a good system, but it may not save us on herbicide costs. And I would see it as like, I think Bruce has stated this as well, but as a good rotational option to kind of shift the you know, from having a completely water-seeded system.

Sarah Marsh Janish: 9:01

I think that's really valuable because I think that's part of one of the most important things people are wanting to know going into the system is, okay, what's my weed control going to look like? Because we don't have a lot of that information.

Whitney Brim-Deforest: 9:13

Yeah, and I did mention this as a field day too, but there is a shift towards grasses. So that's a definite thing that will happen. So you're going to have mostly water grass and spangled top as the two biggest areas weed groups, I would say. The broadleaves don't really come up. We might get red stem later in the season, but like early season broadleaves don't really come up. Might get some small flower, but much fewer plants per area and likely no bulrush. I haven't seen bulrush in drill seeded system. Could again be a good rotational option for folks that have heavy bulrush or broadleaf pressure.

Sarah Marsh Janish: 9:48

Well, speaking of pests, let's go to you, Louise. I know In part of your talk, you might have said it best with an example of showing the bacchané that we saw in the grower's field later on. Would you care to expand a little bit more on that?

Luis Espino: 10:03

During the field day, so I was mentioning what pests could be an issue, arthropods or diseases. And so we know weevil could be an issue. Shrimp and mitch won't be an issue because those are from in flooded situations only. And then on the disease side, so, you know, bacony, we use the seed treatment to control bacony on water-seeded rice, but on drill-seeded, because you're using dry seed that's not soaked, so it's not treated. So you could have bacony. And in fact, in the field, there were two or three plants that had bacony. And so it was a good example that, yeah, you could see it in drill seeding. And then, you know, at that point, we couldn't see anything else. But, you know, other diseases like stem rot and agar-garci spot, I suspect are going to be the same. The one that could be an issue is blast, right? Because blast tends to be worse when it's dry seeded or drill seeded rice. We haven't had a good blast year to kind of look at That in our experiments, but there are some experiences from a few years back that, you know, some people that were drill seeding, you know, in areas where traditionally there's no blast were seeing or saw blast in a, I think it was three or four years ago.

Sarah Marsh Janish: 11:38

And so in that case, I mean, I think your best option just to stave off anything, any blast might be just to plant M210, right?

Luis Espino: 11:45

Right, yeah, that's what I like to do. tell people is if you're gonna try these systems, maybe M210 is the best, you know, or the safest option. But you know, you can't always do that. Like we have done M206 at our sites. And I think some of the growers that are testing the systems are using other varieties as well. So M209, M206. So we'll see.

Sarah Marsh Janish: 12:16

Any other notes you want to make on the no-till field day before we move on?

Luis Espino: 12:20

I think a big driver for growers is the weed control, you know, and trying to reduce costs. But I think there are, so there are other benefits. You know, you can plant earlier if you do the no-till. And there's savings in water. And maybe Bruce can discuss that a little bit more.

Bruce Linquist: 12:41

Yeah, we're seeing about a, 15% overall savings in water in those systems. And all of those savings are coming during the establishment phase where your field is dry for a lot of the times. So those have been measured at the RES where we do a single, we do a flush, and then we don't do any flushes until permanent flood about a month later. The plants do very well. And so we're seeing that sort of It's about five inches of water of ET that we save. But if you do multiple flushes to get that, to establish that rise during that period, really, you're not going to see that type of water savings. It's going to be somewhat comparable to a water seeded system.

Sarah Marsh Janish: 13:29

So a grower who might need to do more than one flush to try and encourage their seed to get up out of the ground might not see the same water savings effect.

Bruce Linquist: 13:38

Correct. And... Again, that gets to seeding depth. I think if you can keep your seed depth shallow, you can potentially avoid having to flush again. Some of that deep seeding where it just takes longer to get out and then you've got a crust forming on the top, it can make it hard for that seed to come out.

Sarah Marsh Janish: 13:59

Great. Thanks for clarifying that. With that, I think we're going to move on to our next main topic, which is going to be a bit about our individual projects or the collaborative projects that we're working on in the 2025 season. And so I'd like to ask Ian to talk first about some of the projects that you're working on. But before I ask you to get into that, I'd love for you to describe a bit about your latest tadpole shrimp catcher, which I know you teased at our grower meetings and I'll say this here, our rice team has actually had the opportunity to use it and we've been pretty excited about it.

Ian Grettenberger: 14:36

Well, that might've been the only thing I talked about regardless, but yeah, so as part of that, we're finishing up a DPR funded grant for tadpole shrimp management. And part of that was developing scouting, better scouting methods. Basically, how do we better find the shrimp in the field, both from an efficiency standpoint, being able to collect them, but then also ideally finding them when they're smaller so that we can be a little more proactive about management and also enable scouting more. Because if we're only able to find shrimp when they're already very large at that point, it's usually pretty obvious that you have them. And some of the insecticides don't work as well for large shrimp. And so you may have missed the boat a little bit to get the best bang for your buck out of some of the insecticides or even just logistically best plan out your applications as well. But yeah, so we're trying to come up with something that was better than just simply staring into the water or sticking your head in a clear bottom bucket. And we were working to develop a scoop based method that started with the fact that we knew we could scoop them somehow. I mean, it was simple pool, a pool net would work, but the problem there is you get a lot of mud and then The shrimp do move around when you scoop them up, but if they're coated in rice mud, they do not. And so finding them would be hard and especially if they're small. And so basically we started from the ground up and design modeled and then 3d printed a scoop. scoop that attaches to a pole basically um that will kind of move through the move through the water column that you can kind of just um pull and scoop up the shrimp and yeah it will catch shrimp and then importantly we've been able to catch shrimp when they're pretty darn small as well which is something that is very hard to do i think with our current management or current options or is just pretty inefficient if you're to use you know the various other tools that are available

Sarah Marsh Janish: 16:26

yeah i mean well selfishly speaking here it's been an absolute delight to just be able to pull this large scoop through the water and then easily sift through the shrimp instead of trying to dig through the soil or trying to catch it when it's very small I think I might throw to Luis here but I think as far as the size of the shrimp that this is able to catch we've noticed that it's pretty on par catching the small shrimp

Luis Espino: 16:53

well yeah maybe it seems to be that way but you know it depends on what you're comparing it with right so The way I was doing it, I was trying to catch as many shrimp as possible with one method, like let's call it the absolute method. And so, you know, we can catch all kinds of shrimp, but it takes a long time. And I wouldn't expect a grower or a PCA to do that. And so if you compare that with the scoop that Ian designed, yeah, you end up catching less of the bigger ones, maybe. But, you know, if you're... Trying to find those, you can see them, one. And two, it's too late, right? At that point, the shrimp might have already caused their damage. So you really want to focus on the little ones. And I think that's where the benefit is because you can see them easily. It's really nice.

Sarah Marsh Janish: 17:45

Ian, I think it's doing what you designed it to, is catching the shrimp when it's important to catch them.

Bruce Linquist: 17:51

Ian, can you set up a little video of how it works?

Ian Grettenberger: 17:55

Yes, I am. either going to do that shortly or definitely can. We already, I shot a little bit of video on, yeah, showing how it works, plus a few photos.

Bruce Linquist: 18:04

Yeah, it'd be nice to have up on our website.

Sarah Marsh Janish: 18:08

Sorry, Ian, got a little sidetracked there. I did want to just quickly ask you, I think we saw a little bit of seed midge in high numbers at the Rice Experiment Station. Is that something you can touch on a bit?

Ian Grettenberger: 18:22

Yeah, generally speaking. I mean, I think... There's been issues with rice seed midge. I think what happens at the station is a little bit driven by the interesting dynamics there in terms of, you know, a small field will get flooded at a timing that is different than everything surrounding it. So you can get some concentrations of adults that will lay eggs that can lead to... potentially abnormal damage in some of those areas. And that's actually what we are, that's what we try to foster when we're doing our insecticide trials or any sort of trials in that we plant lakes, we figure the midges are going to be, the midge populations will be developing. And also if we're one of the last fields to flood our little research plots, research trial area, then we should be able to concentrate whatever midges are around and don't want to over-posit in the already established rice. We'll come find our plot.

Sarah Marsh Janish: 19:15

So what are some of the other insecticide or trials that you're working on this summer?

Ian Grettenberger: 19:19

Yeah, on our end, the focus has been, the last several years, on tadpole shrimp and rice seed midge now. And so tadpole shrimp, like I said, we're sort of finishing up that one project. I think I'd like to continue taking some of these things forward, like the scoop and the scouting side of things. And then otherwise, we're continuously evaluating available insecticides, anything new that we have. There's not a lot that's on the horizon in terms of evaluating. Luis can touch on that, maybe things that he's been trying. But basically looking at different materials for different modes of action, given regulatory concerns, as well as pyrethroid resistance, and then including aspects around timings. So potentially treating the soil pre-flood, as well as kind of different timings with different strip sizes as well. And then on the rice seed midge side of things, we're evaluating materials, including materials that are relevant early season, you know, relevant for rice water weevil, tadpole shrimp, registered, as well as material. We're also looking at a BT-based product that's looked pretty good for several years now. And so continuously evaluating that, looking at different rates.

Sarah Marsh Janish: 20:28

Right. That sounds like some very important work here when it comes to just studying pests in rice. Yeah. Well, Anne, thank you for giving us that information. We will stay kind of in this thematic area and go back to Luis Espino. And Luis, we kind of touched on this when we were giving the summary of the drilled rice project, but I wanted to ask you about rice water weevil and if you're seeing an increase in that in the drilled rice fields.

Luis Espino: 20:59

Well, no. So what happened is we have these basins where we're testing our drill seeded, no-till drill seeded rice. And so it's interesting, but we've noticed that we have some rice water we will injury this year in the no-till drill seeded. Now we have different systems, right? We have the fallow, which is the summer prep. basin and then we have the chopped and the disc where the straw has been either removed or chopped we don't know if the weevil is equally distributed in all these plots you know but yeah we typically don't see this much or we haven't seen this much weevil at the station in Biggs for a few years. And so it's interesting that this year, you know, we're seeing quite a bit on our plots. And so it could be one of the possibilities is that, you know, on our drill seeded no-till, especially on the chopped and the removed, the stand is not 100%. It's more like maybe 80% and 70% in some spots. And so we know that the weevil likes to go into fields that have low stands. And so maybe that could be a reason why we're seeing weevil there. But yeah, I think we're certainly going to plan on looking at this more closely next year and maybe set up some plots so that we can determine if really the weevil is an issue in these systems. Or it's maybe just because I said that we shouldn't be an issue in drought and drill seeded rice. Definitely happens that what you said, the opposite happens in real life.

Sarah Marsh Janish: 22:44

Just keeps things interesting, right? Let's talk about the other project you have going on in this 2025 season.

Luis Espino: 22:52

So we have the army worm traps, you know, and everybody should be getting those emails and we're seeing the moth numbers go up. And so we know that once we're the peak, you know, one, two weeks after that, that's when the armyworms are going to start showing up. We're going to do some fungicide trials in that stem rot. You know, if we get some blast, we'll evaluate that as well. Part of that, we're looking at some of the induced resistance products. You know, this is the second or third year we're looking at those in combination with some of the fungicides we have available. And then also we're doing some more of the sampling of stem rot, trying to find a better timing for stem rot sampling so that you can go earlier about good time and assess how much stem rot you have and decide if you need to do a treatment for stem rot or not. Because right now, the best way to do that would be to wait till drain time, then you can look at that and make a decision for next year, but not, you know, there's nothing you can do at that point. So we're going to continue doing that, that, that project this year. Yeah. And that's, that's, I think that's about it.

Sarah Marsh Janish: 24:12

But yeah, I've been slowly watching the army worm numbers jump up on the army worm trapping network and it's, Do you have any idea? I know it's different every year, but do you have any idea when the peak would generally be at?

Luis Espino: 24:27

So, yeah, it's interesting. So in late planted years, we have seen the peak. It's a little late. It's typically at the end of very late June, early July. That's, you know, when the peak would happen. So this year, you know, and I think we've talked amongst ourselves, you know, we're seeing that there's a broad... window of planting. And so there's fields that were planted early May, and there's fields that were planted very late May. So it's going to be interesting when we're going to see that peak. You know, we'll see. Probably sometime at the end of June, most likely.

Sarah Marsh Janish: 25:05

Makes sense. Whitney, I think we're going to move on to you now and talk a bit about the trials that you're doing. First off, would you mind, I guess, explaining a bit about the watergrass trials? Because I know this is several years of work that you've been doing, and I've been getting a couple of people asking me about them. So would you mind going into detail about that?

Whitney Brim-Deforest: 25:25

Oh, sure. So I guess this is maybe the fourth year officially, but we've been looking for alternatives to the double propanol application. So everyone's been doing double propanol, I would say, at an increasing rate over the past few years. And the reason is, is because we're struggling to control water grass at the cleanup timing, sort of at the, you know, five leaf slash tillering timing. And I've been testing various tank mixes and sort of like follow up, you know, or closely spaced timings of different products. We don't really have anything new coming down the pipeline for the foliar timing. At least nothing that I'm aware of. And so this is kind of, to me, becoming a bigger and bigger problem. We also do have propanol resistance in watergrass And so we're trying to get people away from doing the double propanil. Even though it is working, I will caveat that it is working. And it's working in my trials as well. But we don't want to lose that product because it is very effective. It's probably the most effective product we have for watergrass control. And since we do have resistance, doing two applications in a row or three applications in a row is only going to hasten that selection for more resistance. So I'm really trying to get people into the habit of not using it every single year. So if they're going to do double propanol, I would caution them to not do that multiple years in a row and use something else, you know, in off years. Or the other thing I've been telling folks is that if you're going to do double propanol, to have one of those propanol applications be a tank mix with something else. So whether that's we've been using Abolish, that one's working pretty well, the propanol-abolish tank mix. Another good one is propanol-alloyant or propanol-clencher. But that way we're not just applying propanol, propanol, propanol. We already know how that went with our sedges, and we have widespread propanol-resistant and sedge populations. So we really don't want to go there with the water grass. So we're trying to do our best to provide folks with some alternative applications.

Sarah Marsh Janish: 27:41

Yeah, I mean, like you said, propanol's a great product. We'd like to try to keep it as long as possible, but... Yes.

Whitney Brim-Deforest: 27:48

Yeah. And I will say the other thing that's been happening as to is because it hasn't always been working, even with the double propanol. People have been, in some cases, applying propanol over the label rate or at more timing. So three or four applications of propanol. And we really, really don't want to head down that pathway either. but we want to make sure we're following the labeled rates and not going over the labeled rates for applications in a season, both for safety as well as herbicide resistance. So, you know, there's multiple reasons we don't want to do that.

Sarah Marsh Janish: 28:21

Yeah, lots of reasons there. So I know the watergrass trials take up quite a bit of your time throughout the season, but what are some of the other projects that you're working

Whitney Brim-Deforest: 28:31

on? Well, definitely looking at drill seeded programs. So like I mentioned earlier, so some options hopefully for for both pre-emergent where I'm looking at a product that we might be able to get labeled next year for pre-emergent and then also just programs. So people have more sort of options for, and more guidance, I guess, on what they should be applying in sequence to make sure that they have good weed control in those drill seeded programs. And then there is a hedgerow project that we've been working on for a couple of years in Colusa. So that's, that's, The first ever hedgerow project that I know of in rice. And it's been interesting working with both you, Sarah, and Luis on that. And then let's see, what else do I have going on? Finishing up a cover crop work this year. So we'll have hopefully data published this fall. Let's

Sarah Marsh Janish: 29:23

talk about this new work on Ludwigia. Is that something you can talk about?

Whitney Brim-Deforest: 29:29

Yeah, so we are trying to... with you guys, so Luis and Sarah, and we have some collaborators from USDA as well, and of course the county and commissioners and stuff. We're trying to do a bigger, better mapping program for Ludwigia, which is winged primrose willow. It was found, I believe, in 2010, which you can correct me here if I'm off on my timing, but that's when it was first discovered. It is invasive. It is from the southern United States, and it is considered to be an A-rated pest. So it is not allowed to be in seed fields. So if you had it in a seed field, your seed field could not be harvested. So we've really kind of decided this year that we noticed it moving down some canals in Butte County in the past couple of years. And so we're doing a bigger survey this year. And then myself and my colleague Jens Beetz from USDA is going to work on the aquatic side of things. So he's going to work on some herbicide options for aquatics. And I'm going to work on some for rice. And so hopefully we'll have some better herbicide control options for folks for next year. And then also we're doing the Weedy Rice five-year survey this year as well. So I forgot about that as well. So Weedy Rice five-year survey coming down the pipeline probably in July. We'll be reaching out to folks that have either had Weedy Rice in the past or have it now. And we'll be surveying those fields as well. We're going to see, hopefully, a reduction. I'm assuming there's a reduction. It seems like there is, but now we'll be able to document. Hopefully that there is one.

Sarah Marsh Janish: 31:04

You heard it here. Well, not first, but recently. Whitney says there's going to be a reduction of weedy rice. I

Whitney Brim-Deforest: 31:10

mean, I think there is. I mean, Luis, you can comment too, but it feels like there is. So this year will give us an update as to whether or not our management practices are working from the last time we did it, which was in 2020.

Luis Espino: 31:22

It's either that or people are just less concerned about it, you know, and they're not reaching out because we were getting... calls from PCAs and growers, like, you know, concerned about the weedy rice, if they thought they had it, you know, if they saw a suspect plant. So either they're, because I haven't gotten very many calls in the past, maybe a year or two. So either it's not as much or people are not concerned.

Whitney Brim-Deforest: 31:49

Yeah, well, hopefully we'll be able to tell because we'll be going back and surveying all fields that have previously had an infestation, so. I'm hoping that'll give us a handle on whether or not, yeah, whether it's what Luis is saying or if we're actually seeing reduction in the fields. I've heard anecdotally from growers that their management practices or the management practices we've been recommending have been working. So I'm hoping that we're seeing an actual reduction. But we'll know. We'll know later. Later this year, hopefully.

Sarah Marsh Janish: 32:17

Whitney, thanks for, I guess, giving us that rundown. That is hopefully good, optimistic news. I'm hopeful. I don't think I've gotten hardly any. I think I've gotten one call about weedy rice in the last year. And so I'm optimistic that we've seen an effective management, hopefully. Me

Whitney Brim-Deforest: 32:35

too. Yeah, I got a few last year, none yet this year. But the ones last year, I will say, all were not weedy rice. So in the end, it was just infestations with, like, mix ups of seed or something like that. So yeah, so I'm optimistic as well.

Sarah Marsh Janish: 32:51

All right, Bruce, save the best for last here. But I'm wondering if you could give us a rundown on some of the multitude of projects you're working on, maybe starting first with the variety trials, since everybody always wants to hear about the variety trials.

Bruce Linquist: 33:07

Yeah, so we've got eight different variety trials around the state. And all of us advisors and have been very helpful with setting those up. It's interesting. We actually have a new site over by Winters, so kind of in a cooler area to kind of look at some of that cold adaptation. So we're really looking forward to seeing results from that. I mean, it was kind of interesting. You know, we're looking at just adaptability and just with the spread of the season, we thought these variety trials were all going to be spread out. across the growing season. But apart from one early one, all of our variety trials were planted within the span of about 10 days. So it was a very busy time for us, kind of all in the middle part of May, trying to get these variety trials in. So a very rather narrow planting window this year.

Sarah Marsh Janish: 34:04

What other projects are you working with, Bruce?

Bruce Linquist: 34:07

Yeah, obviously with a number of you guys working on the no-till and so that's already been largely spoken about. You guys are doing different aspects. I'm looking at water use and nitrogen fertility in those systems as well as greenhouse gas emissions. So that's all going well. The other project that we have that's new is we have two large nitrogen by variety trials where we have nine commercial varieties that are quite varied. A lot of them are medium grains, but we have some specialty rice and long grain rice. And we're looking at a range of nitrogen rates, looking at how Is there different nitrogen requirements for these different varieties, as well as looking at the effect of nitrogen on maybe some of the quality parameters of those varieties? So very large experiments and very excited about that. And then, yeah, we're doing some of the AWD work. It's not... We have two... two sites on farm where growers are testing it really at a full farm or not a full farm scale, a full field scale and seeing how that works. And so we're measuring some of the greenhouse gas emissions. I think Whitney might be looking at maybe some impacts on weeds and we're also looking at the impact on arsenic concentration in the grain. So yeah, we're excited about those. And they're actually both, starting in a drain or about to start a drain right now.

Sarah Marsh Janish: 35:47

And so that drain, that'll be, is that approximately seven to 10 days of a drain there?

Bruce Linquist: 35:53

Yeah, it's a seven to 10 day drain. Usually around, it starts 35 to 45 days after planting. So before PI, you want to start that drain. And then once it Once it gets drained, you go for, yeah, seven to 10 days.

Sarah Marsh Janish: 36:13

And can you explain, I guess, why you're looking at alternate wetting and drying or AWD as a practice? What kind of influenced that?

Bruce Linquist: 36:22

Yeah, it initially started with the California Rice Commission asking us to look at ways to reduce arsenic in rice grain. And so that was the initial impetus of that. California doesn't have a huge problem with arsenic in rice. But then it got to be the impact on greenhouse gas emissions, particularly methane. We were looking to see also, and so before, yeah, it does reduce. We can reduce greenhouse gas emissions by about half with that practice. But then the other thing, we were hoping to see a reduction in water use. And there is a small reduction, but it's not large. We're also wondering if there'd be a yield bump with it because a mid-season drain is something that's been practiced for centuries in Japan, China, or they do it for increasing yields. So we haven't seen a statistically significant yield increase, but we haven't seen a decline in yields, and it might be a small increase.

Luis Espino: 37:30

So, Bruce, yeah, you talked about the AWD, you know, during our GRRRR meetings. And I got a question, and the question was, so we've always recommended not to drain to avoid losing nitrogen. And so how does that work with the AWD? How come we're not, you know, losing a bunch of nitrogen when we do that? Yeah, that's a

Bruce Linquist: 37:52

really good question because we're recommending– the drain to occur when the amount of soil nitrogen is low. So by about 45 days after planting, all of your nitrogen that you applied pre-plant has been taken up. So your levels of soil nitrogen are very low at that time. So there's really little to lose at that time period. So if you were to drain very early on, when there's still a lot of nitrogen in the soil, yeah, you'd have huge problems with nitrogen loss. But because we're draining later, the ideal time really to drain is about 40 days, maybe 45. But the practice that's been developed allows for as early as 35 days. There's still a little bit of nitrogen in that soil. And we might be getting into the weeds here a bit, but When you drain a field at 35 days, even if there's a lot of nitrogen, it's going to nitrify or it's going to turn into nitrate. That nitrate's available for plant uptake. So the plant can still take up nitrate. Where you lose it is when you reflood it. And that's going to happen 10 days later. So a lot of that nitrate, most of that nitrate will have been taken up by the plant before you reflood and get that loss. So That's a maybe in the weeds answer to.

Sarah Marsh Janish: 39:21

Actually, I think it's great that you went to detail about that because I think the nitrogen cycle as a whole is really interesting and not altogether well understood. I mean, especially in our rice flooded anaerobic conditions. Bruce, anything else you want to add here?

Bruce Linquist: 39:40

Broadly, I would just say I was looking at, I mean, Louise brought it up, kind of the very extended planting season that we had. We were roughly 20% planted in California by April 27th. And then everything from then on, you know, it was just go, go, go. There was a little lag, maybe because of wind and some forecasted rain. But it's a very stretched out growing season this year. And I think it's going to stretch out the harvest season. And I'd be interested to know, I mean, Luis said maybe there's some impact on army worms or other things, but I think it's going to be a bit of an unusual year in that way. Because we have rice well into PI right now and rice that's very just coming out of the water. I mean, this year we were 50% planted, even though we started really early, our 50% plant date was a little, it was about three days later than an average year. So it was kind of interesting just with that, but whether that's really true or not based on how they collect their stats, I'm not really sure. Also, when you talk about 100%, at the beginning of the year, you don't know how many acres you have. You could have a lot of prevented planting acres, And so all of a sudden, you have a lot of acres out. So what is that 95% or 20% a percentage of? I don't actually know what it is. Because early on, it would be a percentage of your total acres. But when you get to 95% of planted acres, I think at the end of it, you're looking at, well, that's actually the amount of acres that are going to be planted.

Sarah Marsh Janish: 41:29

Shifting goalposts.

Bruce Linquist: 41:31

I think it is a bit. Yeah. Hey, Sarah, you've asked us about all our projects. Are you just going to bail and not talk about your projects?

Sarah Marsh Janish: 41:41

Don't worry. I was going to slip it in here at the end. But yeah, I have a couple of projects that I'm working on this year. One at a grower collaborator field and then a couple up at the Rice Experiment Station next base and over from everybody else. But one of the ones that I'm really starting a pilot study on is uh it's it's a starting work on seeing the effect of reseeding or delayed planting on rice essentially if there's any kind of effect on plant stand establishment if we delay seeding after the flood water has been put onto the field frankly there's just not a lot of data or past information on this subject so At least in California, the last research done on this was in the 60s. So it's a lot of new factors involved in this, new varieties, different measuring technologies. So far, I actually just finished my final planting date today, which is June 18th, which is February. way behind the recommended planting date for rice in California. So it'll be really interesting to see how that project turns out. But yeah, that one's with the end goal of trying to create some kind of recommendation for growers who might have to have, for reasons beyond their control, some kind of delayed planting or maybe a necessary reseeding projects. And For better or for worse, unfortunately, one of Whitney's basins had a bit of a problem with stand establishment due to predation by tadpole shrimp and midge. And so luckily, she's let me take some measurements in there after we reseeded. So we'll be able to kind of compare and contrast what a grower standard for reseeding might be as compared to just seeding into a standing flood. But yeah, unfortunate for Whitney, but lucky for me. And I do promise I did not seed her basin with tadpole shrimp eggs to try and get this result.

Whitney Brim-Deforest: 43:51

Sure, Sarah. Are you sure? It is rather suspicious, right next to mine,

Bruce Linquist: 43:56

yeah. Sarah, you planted your last seeds today. Yes. How long has that field been flooded?

Sarah Marsh Janish: 44:02

That field got flooded May 27th. So today we are 21 days out, which is way beyond the current recommended time period between flooding and seeding. Yeah, I think we're anticipating some challenges with weed controls, especially in these later planted plots. And then one thing I noticed today when I was out there is a lot of my seedlings that are at approximately one to two leaf stage were actually uprooted and I've seen a lot of feathers in my plots. So I'm a little bit afraid that there might be some kind of waterfowl predation that might have some kind of effect on results. But I guess we'll see what happens when the yield map comes through. With that, folks, I think we're going to use this last bit of time to kind of go around our virtual table here and talk about some of the farm calls and questions we've been getting so far. Does anybody want to start off with maybe an interesting question that's come across their desk?

Luis Espino: 45:09

I can start. So, yeah, I've got a couple of calls about bacchani again. And actually this morning I was just driving around and saw a field that looked like it had a lot of bacony in it. And so, yeah, and I, you know, I stopped and ran into the grower and we chatted for a little bit. And so, yeah, there's some fields with some heavy bacony. I don't think it's going to be any economic effect of what we're seeing. But, you know, there's talk about some varieties being more susceptible than others. Some of these fields have been treated with bleach before seeding. I wrote a blog post about this. I'm thinking probably what's going on is the bleach treatments might not be reaching the concentration needed, and that's why we see bacony come through. That's my theory. I mean, it could be a, there's other possibilities, but that's probably what the most plausible, given for what I've seen in previous years, where some fields had heavy bacony, then they, you know, the warehouse started doing a better job of doing the bleach treatments, checking the concentration, and we don't seem to have bacony from in these fields. So that's something that's come up. I think we'll, you know, we'll have to do a little bit more digging around to see what's going on.

Sarah Marsh Janish: 46:48

Louise, I also had people calling me about Bacchanet in treated fields, fields that have been treated with bleach. And so we, I think the group of us actually talked about using bleach testing strips in the soaking tanks to make sure that that concentration is where it needs to be. So that might be something we look into to make sure we can standardize some kind of sanitation protocol.

Luis Espino: 47:12

And yeah, the strips works. But it's tricky because the strips, you can buy strips for up to 2,000 ppm. And those would work for one when you bleach for 24 hours. But then the next level is 10,000 ppm. And I don't know how well they would work for when you bleach two hours. So I was thinking I might buy some and try them out and see. But yeah, I don't know if there's a handheld probe that you can use that will tell you. I'm sure there is, but it's probably expensive.

Sarah Marsh Janish: 47:49

Bruce, what about people calling about going without starter fertilizer? Are you starting to hear a bit more about the outcomes of those decisions?

Bruce Linquist: 48:00

No, that was really the bulk of my calls was related to that. kind of looking to cut costs by putting their, not their starter, but their top dress nitrogen into their aqua. And I think a lot of growers did that this year. Again, we're kind of getting into that time of year when, you know, we're getting into PI when they'd want to start thinking about a top dress. The few growers that I know that have done it aren't thinking that they need to, top dress because of that. But, you know, that's a few of many. So we do recommend that they still evaluate to see if they need it. They shouldn't, but you still want to check.

Luis Espino: 48:46

Maybe, Bruce, maybe you can mention that, you know, method that we were discussing to check if you would need a top dress, you know, over-fertilizing an area.

Bruce Linquist: 48:56

Yeah. So if you have Before the season starts, you can put out a small over-fertilized area into the field. Sometimes it's a cup of urea into a 10 by 10 foot square area in a representative part of your field. When it comes to PI, either in that section or maybe you know you have some aqua overlaps or something where we have excess nitrogen. If you don't see a difference between that enriched area where there's extra nitrogen and the rest of the field, you're not going to need to apply top dress. And so that's an easy way to tell if you don't need to apply top dress. The question then becomes, do you need to apply top dress? You may need to do it if you do see a very visible difference between those two treatments. And that's where the green seeker or maybe the leaf color chart can come in and help make that decision. But certainly if you can't see a difference where you've applied excess nitrogen and the rest of the field, you won't need to be applying a top dress nitrogen.

Sarah Marsh Janish: 50:09

I had on my list here, a couple of the calls, actually all of the calls I've had so far have been about stand establishment issues, funnily enough. The two calls that I've gone on this year to check it out, it was kind of inconclusive, but I think together the PCA and I decided that it was most likely due to geese pressure. Tons of feathers in the field, lots of problems with just like stand establishment and a single check in a field rather than spread across the entire check. So that's something I think we saw at least in a couple of our fields last year, but it looks like it might also change. a problem in some fields this year maybe due to the extended planting period the geese are able or geese or waterfowl are looking for places to go i don't know if any of you guys have heard tell of i guess predation from geese or other kinds of birds

Whitney Brim-Deforest: 51:04

not this year but yeah i mean i seem to have a lot of issues in a lot of my trials in the past

Bruce Linquist: 51:09

this year maybe with the earlier start that at least some growers had.

Whitney Brim-Deforest: 51:14

That could

Sarah Marsh Janish: 51:14

be.

Bruce Linquist: 51:15

There may have been some extra geese pressure, especially maybe on the west side.

Sarah Marsh Janish: 51:19

It was definitely on the west side. I think at least in the Reclamation District 108, we saw a ton of birds there while planting was going on.

Whitney Brim-Deforest: 51:30

Were they earlier planted fields of curiosity? Yeah. Okay. Yeah, that makes sense.

Luis Espino: 51:36

Well, Sarah, we visited that field that definitely had some geese or ducks you know, damage. It was kind of planted a little later, more towards the end of the month. It wasn't a big area, but you can tell that they had been there. You know, you can see all the feathers.

Sarah Marsh Janish: 51:52

Any other calls we want to bring up here? I

Whitney Brim-Deforest: 51:55

mean, I'll just say that I've been getting a lot of calls about water grass control. So, but that doesn't really, it's not new. So, but it's, yeah, a lot of calls, just people wondering how to control their grasses and what they should put on.

Luis Espino: 52:08

So one question I got from at least two people was, what's the benefit or the difference between Cliffhanger and Butte?

Whitney Brim-Deforest: 52:18

Just the AI is different. So Butte has a halosulfuron mixed in. So it's halosulfuron plus benzoyl cyclone. So that's one difference. But Cliffhanger can go on a lot later in the season in comparison to Butte. So the timing can be later with Cliffhanger. So that's one of the benefits. But I think both products are great. But yeah, cliffhanger allows a little bit more flexibility and timing. But it is not a foliar product, just to re-clarify with everyone. Somebody else asked me that today. Not a foliar product. It's meant to be applied into the water. It does not work on established weeds out of the water. So it's an into-the-water product as well.

Sarah Marsh Janish: 52:59

Yeah, and if you're going to use cliffhanger, you need to make sure you're going to be able to keep that water up at least four inches, preferably higher. But that's, I think, in cases where I've seen, I guess, a failure of control, it's usually been because of a lack of water or a lack of depth of water or a lack of time of keeping the water on.

Whitney Brim-Deforest: 53:22

Yeah, I would agree with that.

Sarah Marsh Janish: 53:25

Great. Well, thank you guys again so much for taking the time to be here. A lot of really good stuff. A lot of really good information. Glad to be back recording after our planting hiatus and let's have a good season. Thanks,

Whitney Brim-Deforest: 53:38

Sarah. Bye. Bye, guys. All right. Thanks, Sarah. See you guys. All right. Bye, folks.

Sarah Marsh Janish: 53:55

We've got a couple of upcoming events that are rapidly approaching. The first event that's up on our schedule is the rice production workshop. which is a workshop we hold every two years to cover the basic principles and practices of rice production in California. This event will take place July 23rd and July 24th, 2025. This is a two-day workshop. These will be two all days, so it will start at 8.30am and go till 3.30pm and take place at the UC A&R building on 2801 2nd Street in Davis. Registration is required for this event and if you go to our UC Rice website, there is a link for that registration. Our next upcoming event will be the Weedy Rice Workshop, which will take place August 5th, 2025, from 10 a.m. to 1.15 p.m. at the Roberts Union Farm Center in Stockton, California. This will be a workshop devoted to the history and current management practices of weedy rice in California. Registration is not required for this event. Our final upcoming event for this season is the annual Rice Field Day, which takes place every year on the last Wednesday of August, which is August 27, 2025. It starts promptly in the morning, so be sure to get your coffee and donuts when the field day starts. And it will take place at the Rice Experiment Station at 955 Butte City Highway in Biggs. And as always, stay tuned for some great talks and delicious lunch. For more information about these and other upcoming events, feel free to check out our resources, which include the UC Rice blog and the UC Agronomy Rice website. In terms of other resources you may want to take advantage of, you can also look at our newsletters, which include Rice Briefs, which covers Colosiolo, Rice Notes, which covers Yuba Stutter, Rice Leaf, which covers Butte and Glen, and Field Notes, which covers rice in the Delta region of California. Thanks for listening to Thoughts on Rice, a University of California Cooperative Extension podcast from University of California Agriculture and Natural Resources. You can find out more about this podcast on our website, thoughtsonrice.buzzsprout.com. We'd love to hear from you, whether it's from using our text link in the show notes, a survey submission in our feedback form, also in the show notes, or or in a comment or rating on your podcast streaming service of choice. You can also email us with any comments, questions, or concerns at thoughtsonriceatucdavis.edu. Thanks for sticking with us over this planting hiatus earlier this spring. Rice season is well underway and we hope you stay safe this season. And remember, like the growers like to say, have a rice life. Mention of an agrochemical does not constitute recommendation, merely the sharing of research findings. Always follow the label. The label is the law. Find out more at ipm.ucanr.edu. The views, thoughts, and opinions expressed are the speaker's own and do not represent the views, thoughts, and opinions of the University of California. The material and information presented here is for general purposes only. The University of California name in all forms and abbreviations are the property of its owner, and its use does not imply endorsement of or opposition to any specific organization, product, or service.