January 27, 2025 • 39 mins
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Together, the UCCE Farm Advisors seek to provide relevant, topical research-backed information relating to CA rice production.
Sarah Marsh Janish and Luis Espino discussed the 2024 Rice Disease Survey, the results of which showed a low incidence of blast and similar levels of other diseases compared to previous years. The conversation also covered the influence of agronomic practices on diseases in rice crops, the importance of fungicide applications, and the differences in diseases and insect problems between California rice and the mid-south region.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
SPEAKER_01 (00:00):
Hello and welcome to Thoughts on Rice, a podcast
hosted by the University ofCalifornia Cooperative Extension
Rice Advisors.
I'm one of your hosts, SarahMarchionish, and I'm a rice farm
(00:21):
advisor for Colusa and Yolocounties.
SPEAKER_02 (00:24):
I'm Whitney from the forest.
I'm the Cooperative ExtensionRice Advisor for Sutter, Yuba,
Placer, and Sacramento counties.
SPEAKER_03 (00:31):
My name is Luis Espino.
I'm the Rice Farming SystemsAdvisor for Butte and Glynn
SPEAKER_00 (00:38):
counties.
I'm Michelle Leinfelder-Miles.
I'm a farm advisor in the Deltaregion.
I work on all sorts of fieldcrops, grains and forages, but
one of those is rice.
And the counties that I coverare San Joaquin, Sacramento,
Yolo-Solano, and Contra Costacounties.
SPEAKER_01 (00:56):
Together, the UCCE Rice Farm Advisors seek to
provide relevant, topical,research-backed information
relating to California riceproduction.
Today, Luis Espino and I get totalk about the results of the
2024 Rice Disease Survey, whichwe compiled this last season.
(01:19):
The objective of the survey isto document the incidence of
rice diseases in SacramentoValley rice fields, so that the
California Air Resources Boardagrees to continue to allow the
rice industry to burn up to 25%of the available rice acreage.
(01:54):
Luis.
Hi,
SPEAKER_03 (01:55):
Sarah.
SPEAKER_01 (01:55):
How are you?
Good.
SPEAKER_03 (01:57):
Happy New Year.
SPEAKER_01 (01:58):
How are you?
Happy New Year.
Happy New Year.
Yeah, all good.
Let's chat about the RiceDisease Survey.
Since 2014, we've performed thissurvey every five years.
And when I say we, I meanUniversity of California
Cooperative Extension.
So can you tell me a bit aboutwhat happened to cause this
disease survey to start?
SPEAKER_03 (02:19):
Yeah.
So, you know, back in the early2000s, we transitioned from
straw burning in any field toonly 25% of the acreage.
And so when that transitionhappened, initially, the grower
(02:39):
had to prove that he haddiseases in the field.
And so they were trained by, youknow, at the time, the farm
advisors.
And then at some point, alsomaybe the ag biologists from the
ag commissioner's offices.
So they would come and inspectthe fields and kind of show that
(03:00):
there was disease and documentthat before they could be
allowed to burn.
So what happened was that everyinspection that was made showed
that, yes, there was disease asexpected, and the fields were
allowed to be burned.
And so at some point, it wasdecided that it would make more
(03:21):
sense to just show the level ofdisease valley-wide and use that
as a proxy of how much diseaseis there in the field.
And so that's why we do it thisway now.
Instead of having the grower,you know, having to certify that
he has disease, having somebodycome to inspect, you know, we
(03:42):
just use the informationgenerated from the survey and
say like, yes, we're stillseeing diseases and burning is a
good way of reducing diseaseinoculants.
SPEAKER_01 (03:52):
Yeah, that seems like that places a lot of burden
on the grower and the agcommissioners to go out and
inspect all of these fieldsprior to allocating a burn
permit.
SPEAKER_03 (04:02):
Right.
SPEAKER_01 (04:03):
It seems like the Rice Disease Survey is a lot
more efficient.
SPEAKER_03 (04:06):
Yeah, I think it serves that purpose.
And it also, I think it gives usfarm advisors and specialists,
people working on rice, gives usa good overview of what's going
on in the field and how muchdisease is out there.
SPEAKER_01 (04:21):
Absolutely.
Really valuable informationcoming out of the disease
survey.
Let's go into the methodology ofthe disease survey itself.
What does it look like when wedo the disease survey?
How long does it take?
How many counties?
How do we decide how muchdisease is in our rice field?
SPEAKER_03 (04:38):
What we do is in drain time.
So late August, early September,we start the survey because
that's the time when we're goingto see the diseases most
severely affecting the rice.
So they're easier to identify.
And so what we do is we take ateam of anywhere between five,
(05:01):
six, seven scouts and we just goacross the valley and we have a
number of fields that that weneed to inspect and so for the
large counties like you knowrice growing counties like
colusa glen butte we do 10fields and then for the medium
(05:22):
size we do five and then for thesmaller counties you know like
maybe sacramento or placer wejust do two fields and and those
numbers are so of arbitrary youknow but I think they they give
us a good idea of geographicallyit kind of show up real nice on
the map so it gives you a gooddistribution of of the fields in
(05:46):
the map and so we go to fieldsyou know that we have a number
of fields and we just randomlychoose fields we go into these
fields and every one of thescouts goes in and then we do a
certain number of stops in thefield, and on each stop, the
scouts would look for the fourmain diseases that we have.
(06:08):
So we look for stem rot,aggregate sheath spot, kernel
smut, and blast.
And this year, we did see alittle bit of bacony.
And so we noted that.
Not a lot, but there was, youknow, in the past, we had never
really run into bacony.
So this was the first year thatwe were seeing bacony.
So we noted that as well.
(06:28):
So we then, we just go bypresence, absence.
So we're not really trying toquantify on a stop like how many
tillers show stem rot or howmany panicles have blast.
We just look for presenceabsence.
And so each scout does a numberof stops and we shoot for at
(06:52):
least 30 observations per field.
And so we have 30 observationsand then we move on to the next
field.
And so with that, we can kind ofhave a feeling or we can
calculate a percent incidence ofthe four diseases.
SPEAKER_01 (07:08):
So with all of these stops, I think I read in your
report that there are over 1600individual observations made
across the race disease survey.
So it seems like that's a prettyrobust data set to get an idea
of how much disease is in thearea.
SPEAKER_03 (07:23):
Yeah, yeah, I think so.
And it's interesting becausewe've been doing this now.
This is our third time doing it.
So we do it every five years.
This is the third time we doneit.
And so I've been looking at whatwe did the two previous times
and a couple of diseases, stemrot and aggravation spot, they
are pretty much the same.
(07:44):
The levels that we see have beenvery, very similar.
SPEAKER_01 (07:48):
Interesting.
SPEAKER_03 (07:49):
Yeah.
But blast, for example, which isa disease that varies quite a
bit.
In some years we see more andthis year we only run into a few
fields where we saw one panic ineach field with blast.
So very low levels.
And that's what we've seenduring the season, kind of just
(08:11):
looking around and responding toPCAs and growers calls.
If they were suspecting blast, Iwent to a couple of those and it
was in blast, right?
So we kind of knew that it was alow blast year, but yeah, with
the survey, we know like, yeah,very little blast out there.
SPEAKER_01 (08:28):
It's great though, that you can see immediately
that reflection of how accuratethe disease survey has been, at
least with the blast survey,with the real life results that
we're seeing in the field of notvery much blast recorded in the
disease survey, not very muchblast reported, at least to us
and across the rice growingregion.
SPEAKER_03 (08:46):
Right.
And then with the tillerdiseases, you know, like stem
rot and aggregation spot.
So those, you know, we've talkedabout them at grower meetings
quite a bit.
Those go, the inoculum goes intothe field.
And so you would expect thatthey would be somewhat similar
every year, if not increasingover time, but it doesn't seem
to be increasing.
(09:07):
It's already pretty, they'represent pretty widespread across
the valley.
So yeah, it makes sense thatevery year we find about
roughly, you know, the sameamount of observations positive
for those two diseases.
And the same with Colonel's mud,it varies a little bit, right?
Depending on the year.
SPEAKER_01 (09:27):
Any other differences between this recent
disease survey and the pastdisease surveys in terms of
disease proportions?
SPEAKER_03 (09:35):
I think the main one was blast.
And then that's, you know, thatdepends on the years.
If we would have done the surveyin 2023, which was a blast year,
we would have found it in a lotmore places, right?
But no, everything else, like Isaid, was similar and with the
added of identifying somebacchani here and there.
SPEAKER_01 (09:57):
Let's go over this a little bit.
So we talked about how thisyear, unlike other years, we did
see some more Bacchanet.
And can you explain why weusually don't search for
Bacchanet during the ricedisease survey?
SPEAKER_03 (10:11):
Yeah, it was something we didn't look for in
the past because we didn'treally have Bacchanet levels
that would be identifiable atthat time.
We've seen over the past, Idon't know, now it's been maybe
like four years or so, threeyears, an increase in bacony, I
(10:35):
suspect it comes mostly from areduction in the use of bleach
as a seed treatment.
SPEAKER_01 (10:44):
Because just for people who aren't aware, that's
when we treat for bacony.
Before we fly on our seed, we'llsoak the seed in a bleach
solution for a period of timebefore flying on the seed, and
that can help kill the baconybefore it actually takes effect
on the plant itself.
SPEAKER_03 (11:01):
Right.
It kind of disinfests the seed.
So bacony is transmitted mostlyon the seed.
And so treating the seed withthe bleach really, it's really
effective.
You know, you can have someinstances where you do see
bacony in treated seed, but forthe most part, it's very
unusual.
And so with these, you know,previous years, we were seeing a
(11:23):
little bit more bacony.
It looks like, you know, maybebecause not all seed is being
treated.
So some of what happens is thethe seedlings that get infected
most of them die before theydon't really last past tillering
but there are a few that willsurvive and then those will
(11:44):
develop symptoms towards the endof the cycle and so the plants
just by the time the panicleshould be produced the panicle
comes out but it's blanked andthen the whole plant just starts
dying and you can see thesporulation on the tiller and So
they're kind of easy to identifyonce you see them.
(12:06):
But there's not many of them.
But, you know, it's interestingthat we were not finding any of
those in the past.
And now we're seeing a littlebit.
SPEAKER_01 (12:13):
Yeah.
Going on to that, what do wethen do with the results of the
disease survey?
We've collected all thisinformation.
You've compiled it.
You've made the statisticalanalysis.
But what do we do with it then?
Does it just sit in a drawer ordoes it go somewhere?
SPEAKER_03 (12:27):
Well, no.
So this information then isprovided.
to the Air Resources Board.
We present the information andthey use that to kind of make
the determination that yes, youknow, there's diseases are still
a problem in rice cultivation.
And so we're going to continuewith the burn program and, you
(12:50):
know, letting growers burn up to25%.
That's the main use of theinformation.
So we're getting some otherinformation in terms of, you
know, how widespread some ofthese diseases were and And
also, if there was anything newthat would be starting any new
disease and we started to pickit up on the survey, that would
(13:11):
be also helpful to know there'ssomething that we need to start
doing to prevent something elsecoming to affect us.
SPEAKER_01 (13:19):
Just anecdotally, having done the disease survey
with you and the team thissummer, it was also a great
opportunity to get a look atsome weeds that we were seeing
in the field, just in randomfields that we happened to be
surveying.
some different weeds than wewere usually seeing around rice
fields.
So as far as just getting moreinformation in terms of rice
(13:40):
production, being in the fielditself seemed to be pretty
anecdotally important.
SPEAKER_03 (13:45):
Oh, yeah.
Yeah.
You get to see things thatotherwise you might miss, you
know, because you're not reallylooking.
Something related to that, forexample, we were on a field
where we started to find a lotof army wounds.
That was interesting because youknow, we do the armyworm
trapping and we do monitor forarmyworm.
(14:06):
So we have three or four fieldsthat we monitor through the
season to see what thepopulation is doing.
And we were not finding anyarmyworms at heading.
But when we visited this field,there was a ton of armyworms.
SPEAKER_01 (14:19):
And that's later in the season than we usually see a
lot of armyworms, right?
SPEAKER_03 (14:23):
Yeah.
I mean, they can still be thereat heading.
So brings home the message thatevery field is a little bit
different and you can have a lotof fields with now no armyworms
on them or no disease.
And then there are some fieldsthat for whatever reason, they
will have a lot more pressure.
Always like to think about, youknow, what one of my teachers
(14:45):
said, you know, the best thingyou can put in your field is
your shadow because you have tobe in your field to know what's
going on.
SPEAKER_01 (14:52):
I like that.
That's really, really importantbecause, yeah, you can see
things from your truck, from theside of the field, but the
reality is you You're not goingto see the full picture.
SPEAKER_03 (15:03):
Yeah, or just hearing, you know, what's going
on, like the neighbors or if theACAs are saying, oh, we're not
seeing any of this, but younever know.
It's always good to go and takea look.
SPEAKER_01 (15:14):
So in the recent disease survey, we saw different
diseases that were prevalentacross the region and actually
saw higher incidences of some ofthe diseases in specific sub
areas.
And so, for example, we saw thatGlenn County actually had the
highest incidence of stem rot.
So can you explain why thedisease presence might be higher
(15:35):
in some areas versus others?
SPEAKER_03 (15:36):
Well, you know, there are some differences in
terms of weather.
Up north, it tends to be alittle warmer.
Glynn County can have a littlewarmer weather than some of the
southern part of the valley.
And so that can be acontributing factor.
I don't know if there's really avariety effect.
(15:57):
You know, I haven't looked atthe acreage of the different
varieties per county or regionso I don't know if that would be
but my guess is it's probablymostly weather related and so
for example we did see more stemrot and typically if this would
have been a blast year we wouldhave seen most of the blast up
(16:19):
on Glen County and Colusa Countybecause those are the areas
where we you know the weatherseems to be more favorable for
blast but also thinking ofanother disease and this is
aggregate sheath spot, which isnot a major disease, you know,
but it's present, it'swidespread.
It was a little bit morenoticeable on the east side of
(16:42):
the valley, which we know that,you know, it's soil related and
related to potassium.
And so some of the soils on theeast side tend to be more
deficient on potassium justbecause of the type of clay that
they have.
And so we tend to see a littlebit more of aggregate sheath
spot.
SPEAKER_01 (17:01):
Okay.
So I guess two of these diseasesthen, and you've mentioned them
already, but stem rot andaggregate sheet spot can
actually be pretty highlyinfluenced by agronomic
practices, which can includefertility, like added fertility
and straw management.
Can you touch on a little bitabout how these agronomic
(17:22):
practices can influence thedevelopment of these diseases?
SPEAKER_03 (17:26):
Yeah.
So I think, you know, for thetiller diseases, yeah, there's
nitrogen certainly has a astrong effect on stem rot.
And unfortunately, you know, weneed nitrogen and we need
nitrogen to reach our yields,you know, the optimal yields.
(17:47):
But the more nitrogen you addmakes the plants more
susceptible to stem rot.
So in some cases, it's kind ofhard to avoid, you know, you're
not going to reduce yournitrogen just to have less stem
rot.
Right.
But I think it's important tokeep mind because you know you
don't want to do you know addnitrogen as thinking of well
(18:10):
maybe just as an insurance orwithout properly assessing the
need of the of the crop rightlike you know if you're going to
use a top dress well maybe goout and use the leaf color chart
and and make sure that you doneed it with aggregate sheet
spot it's more related topotassium and so if you have a
(18:33):
Potassium deficiency aggregationcan be problematic.
I wouldn't say a major problem,but it can be problematic.
And it's similar for stem rot.
So stem rot can also be moresevere when there's a potassium
deficiency.
And so potassium, it's a veryimportant nutrient.
(18:56):
And I think most of the growersand the PCAs on the east side
know that very well becausethey've seen it.
But a lot of times on the Westside, we're not so aware of it
because we've always thoughtthat we have plenty of potassium
and that deficiencies will notoccur.
But we've seen the potassiumdeficiency symptoms on the West
(19:18):
side.
And, you know, it could be justthat the information about, you
know, having enough potassium,it's from quite a few years
back.
And so the varieties aredifferent.
Our yields are higher, you know,than say 30 40 years ago our
yields are much higher so we'reextracting quite a bit more so
(19:38):
so yeah we've seen potassiumdeficiency symptoms on the west
side so it's something that it'simportant to keep in mind that
review your your soil fertilityyou know add soil sample leave
sample and make sure that youhave enough in there because it
not only affects the plantsdirectly but then you can end up
(19:59):
with more disease level moredisease pressure by not
addressing the fertility.
And then blast also is relatedto nitrogen.
So the same as with stem rot,you know, if you have too much
nitrogen, then your blast can bemore severe.
But that's another one where,well, you know, we need the
(20:20):
yield, so we can't really cutdown much on nitrogen.
SPEAKER_01 (20:24):
Yeah, you can't tell someone, hey, you might have a
disease next year, so cut backon your nitrogen.
That's not going to fly.
Is there data to suggest thatthat the reduction of burning of
rice straw has influenced therate of potassium available in
the soils?
SPEAKER_03 (20:40):
I don't
SPEAKER_01 (20:40):
think
SPEAKER_03 (20:40):
anybody's looked at
SPEAKER_01 (20:41):
that.
I feel like it'd be hard to testthat.
SPEAKER_03 (20:44):
Yeah, I mean, you would have to go back in time
and find some soil samples.
And there might be some, becauseBruce did some work just
recently on potassium levelsacross the valley.
So that information isavailable.
And I know there is someinformation, I I can't remember,
but it's some of the work that Ithink Scardacci did.
(21:06):
And I think he looked atpotassium.
There's something floatingaround there.
So one could look, go back andlook at and compare levels, but
I don't know how scientific thatwould be because not the same
fields,
SPEAKER_01 (21:18):
not a lot of control in that.
SPEAKER_03 (21:20):
Right.
But it would be an interestingexercise.
Yeah.
I started working on rice herein California in 2007.
And, you know, I worked them,but with, with Chris Greer, uh,
Chris was a plant pathologist,and so I helped him with some of
his work, and we would do somefungicide trials.
(21:40):
And it's interesting because hedid trials at least for a couple
of years, and we couldn't findan effect on...
Basically, we were testing aquadris or a soxistropin, and we
didn't see an effect on thetiller diseases.
SPEAKER_01 (21:56):
Interesting.
SPEAKER_03 (21:57):
And then he moved out of the area, and so we
really didn't...
do any work for a few yearsuntil maybe 2018 or 2019 when I
started doing again.
After having quite a bit ofgrowers coming with disease
issues, I started doing thetrials again.
And then we started seeing astrong effect of asoxystrobin on
(22:20):
the tiller diseases.
And so that might be related tothe burn over the years as we've
stopped burning.
We might be increasing ourinoculum levels to the point
where in the past, there wasn'tenough disease to show an
effect.
SPEAKER_01 (22:38):
But now there's higher levels of disease and
then the azoxystrobin.
SPEAKER_03 (22:41):
Yeah, maybe with this body.
So you would pick it up here,but not there.
But now after, you know, almost20 years of no burning, we do
see an effect.
I mean, it's, yeah, and it'sreally obvious.
SPEAKER_01 (22:54):
While we're talking about straw anyway.
So the pathogens that cause therice diseases, the tiller
diseases, they can actuallyoverwinter in the rice straw in
the form called sclerotia.
And that can actually survive inthe tissue and accumulate in the
soil over time.
Is there another way besidesburning to reduce the survival
(23:17):
of the sclerotia in the ricefields?
SPEAKER_03 (23:20):
Yeah.
So the sclerotia, you know, theywill remain on the rice.
And then early in the spring,when it starts warming up, you
know, say March, April.
So those sclerotia willgerminate and they'll use the
rice straw as a food source andthen produce more sclerotia,
(23:44):
produce more inoculum.
And so if you decompose the ricestraw so that it's not
available, then you can reducethat increase that we get, not
during the season, but later,after during the fallow period.
(24:05):
So that's why it's important toget, you know, if you're not
burning, to try to get gooddecomp, because that's limiting
how much inoculum is beingproduced in the field.
SPEAKER_01 (24:14):
So a method, maybe flood, stomp the field, try and
get that straw to decompose.
SPEAKER_03 (24:20):
Yeah, anything you can do to promote straw
decomposition will help.
Of course, burning is the best.
And if you reduce the amount ofstraw in the field, so if you're
baling, that will would also, wecan say, theoretically help.
But I don't think we have anyactual data to prove that baling
(24:41):
helps.
You know, when you bale, you'restill leaving half the straw
behind.
You can't cut it all the way tothe ground.
And there's always going to besome straw.
Just like when you burn, youalso, you know, there's always
some left behind.
But yeah, but you're reducingthe amount of substrate that,
you know, the pathogen will haveto increase more inoculate, to
(25:03):
produce more inoculum later.
SPEAKER_01 (25:04):
Is there evidence to support the survival of the
sclerotia in the baled strawbales that come off the field so
that if they were broken up,they could potentially spread
disease somewhere else?
SPEAKER_03 (25:19):
I guess they could.
There's some work from BobWebster, who used to be the
plant pathologist at UC Davis,and he determined that the
half-life of the sclerotia istwo years.
SPEAKER_01 (25:33):
Wow.
Wow.
SPEAKER_03 (25:33):
Yeah.
So yeah, if there was sclerotiain the rice straw, and you know,
that that straw is movedsomewhere else, I guess they
could survive.
SPEAKER_01 (25:42):
Theoretically, theoretically, yeah.
SPEAKER_03 (25:44):
Yeah.
But you know, as long as they'renot put back in the rice field,
you know, it would be
SPEAKER_01 (25:49):
doesn't really matter.
SPEAKER_03 (25:51):
Yeah, it wouldn't be a problem.
SPEAKER_01 (25:53):
Okay, so we spent a lot of time talking about the
diseases.
And I want to note here, wehaven't talked a lot about
control of the diseases inseason and a point of that, I
think, comes back to apresentation I saw you make a
few months ago, where you weretalking about disease
management.
And then the next slide wasquadris management.
(26:15):
Because in California, we don'thave a lot of chemicals we can
use to control rice diseases.
Would you like to touch on, Iguess, the availability or lack
of availability of chemicalcontrol of rice diseases in
California?
SPEAKER_03 (26:29):
Yeah.
Yeah, we don't have really a lotof fungicide We really have two,
you know, we have azoxystrobinand it does work and we do have
propiconazole and that one, it'sonly for Colonel's mud.
So yeah, those two fungicidesare available for the rice
(26:51):
industry.
And so it's important to usethem, you know, correctly.
You know, the timing is veryimportant, especially for blast
and Colonel's mud and and stemrot.
I found that aggregate sheetspot, you know, the timing is
not so critical.
We tend to get control even ifyou put it on too early.
(27:13):
But if you go either too earlyor too late with stem rot, you
don't get as good control.
It has to be very early heading.
That's when we get the bestcontrol for stem rot.
And with blast, it's similar.
We get it, you know, the bestcontrol is early heading, maybe
starting from late boot to earlyheading that that might be a
(27:35):
good time and then when you'reif you're thinking of kernel
smart kernel smart the timing isgoing to be uh at the at the
boot stage so if you go too lateif you go early heading that's
that's too late for for kernelsmart so it's a little you know
it could get a little confusingbut so i think you know when
we're talking about diseasemanagement it's between the uh
(27:59):
the boot stage maybe mid boot tothe early heading stage that's
That's the window for fungicideapplications.
And then, you know, it'schallenging because a lot of
these diseases like blast andkernel smut, we don't see them
at that time.
SPEAKER_01 (28:13):
Right.
SPEAKER_03 (28:14):
At least with blast, if you've seen leaf blast, then
you have something to go on.
It's like, okay, yeah, we needto do a treatment because we
might get some neck blast.
But with kernel smut, it'stricky because, you know, kernel
smut
SPEAKER_01 (28:27):
doesn't...
You can't even see the kernelsyet.
Yeah.
SPEAKER_03 (28:29):
Yeah.
It doesn't show until thepanicle is mature So you really
have to go with the history ofthe field, you know, and the
area.
If kernel smut's been a problemin the past, you know, then you
might decide to do a treatment.
Now, with the Taylor diseases,you can do an assessment in the
field to see how much you have.
(28:50):
And we're doing some work onthat.
And I think we have some datathat shows that, yeah, you can
relate, especially stem rot.
We haven't had enough fields ofaggregations, but to make
conclusions.
But stem rot, You can go in atthe boot stage and make an
assessment of how much stem rotyou have and predict how much
you're going to have at the endof the season.
(29:11):
And so make a decision as to, isthis going to really affect the
yield or not?
So we're going to do that againthis year.
And based on that, maybe here inthe future, we can come up with
a more systematic way ofdetermining stem rot levels
before the end of the season.
(29:32):
That's when you really see thestem rot cause the effects on
the plant.
SPEAKER_01 (29:36):
Wow, that sounds like there's some interesting
things in the pipeline.
SPEAKER_03 (29:39):
Yeah, and it might help also make decisions.
If you see that you're havinghigh levels of stem rot, you
might try to get that fieldburned.
Now, you don't have to make thatdecision very early.
You can wait till we harvest.
Or you can make decisions aboutwhat variety you want to have
(29:59):
there.
So we know that varieties thatthat have very short periods of
development tend to be moresusceptible.
And, you know, the stemmer willbe more severe in varieties
like, you know, M105 or thesweet rice.
And so you might want to go witha 209 or 211.
SPEAKER_00 (30:18):
401?
SPEAKER_03 (30:19):
401, yeah.
After last year, I don't know ifanybody wants to go with a 401.
SPEAKER_01 (30:25):
But we'll see how much agar just planted next
year.
SPEAKER_03 (30:27):
Yeah, yeah, we'll see.
SPEAKER_01 (30:29):
I mean, we've been talking about this this whole
time.
We've only got these...
basically four diseases inCalifornia rice.
But in the Mid-South region,they deal with a lot of
diseases.
The insect problems too, but alot more diseases compared to us
all the way out here.
Can you talk a little bit aboutwhy there's so much of a
difference in the two geographicregions?
SPEAKER_03 (30:50):
Yeah, I think the main reason is the weather.
So we have our nice dry summerwith no rainfall.
SPEAKER_01 (30:59):
I've told people that out there, they cannot
believe it.
And I tell them the rain stopsand then it doesn't start again
until Thanksgiving and theythink I'm lying.
But it's true out here.
SPEAKER_03 (31:32):
Probably the fact that we're somewhat isolated,
you know, we're not near any ofthe southern states that produce
rice might help us too.
You know, we don't have thingscoming, get being introduced,
you know, or the risk of thingsgetting introduced is lower.
And, you know, if you thinkabout it, the only diseases that
(31:53):
we currently have that kind ofwere here all along are the
tiller diseases.
Blast was introduced sometime inthe 90s.
Kernelsmod I think it was firstfound sometime in the 80s.
So yeah, we just don't have theconditions that diseases or
pathogens like.
You know, another thing is Ithink the industry has been
(32:14):
really smart in making sure thatany materials that come into
California, any rice seed thatcomes into California, there's a
protocol that has to befollowed.
You know, it has to go in thegreenhouse first, make sure that
there's nothing on it that wouldbe harmful to the industry.
And so I think that's that helpstoo in reducing the risk of
(32:36):
getting something introduced.
SPEAKER_01 (32:38):
We had Timothy Blank on here a while ago talking
about the Rice Quality AssuranceProgram, the Seed Certification
Program, and part of therationale behind those programs
was also maintainingdisease-free, weed-free seed.
And so there's been a lot ofindustry effort focused on
maintaining the quality of riceseed in California.
SPEAKER_03 (32:59):
Yeah, and that's another very important Yeah, I
know Timothy won't let a fieldthat's full of, say, blast or
backening, you know, to be aseed field.
So, yeah.
SPEAKER_01 (33:11):
Well, Luis, I think we're about done with the
lecture part of our talk, but Ijust started doing something
recently and I had poor TimJohnson was my first
experimental person on thisquestion, but you get to be the
second.
SPEAKER_03 (33:25):
Okay.
SPEAKER_01 (33:26):
What is your favorite rice variety to eat or
consume in some fashion?
SPEAKER_03 (33:32):
So, So my favorite type is medium grain rice.
SPEAKER_01 (33:36):
That's a good answer.
SPEAKER_03 (33:37):
Yeah.
Now, my wife, though, she likesmore the basmati, which we don't
eat all the time, but she tendsto favor the long grains and I
tend to favor the medium grains.
Whenever I buy the rice or I geta sample, I buy medium, you
know, I get medium grain andthen we eat medium grain.
(33:58):
And, you know, to me, I can eatanything with rice, but for her,
is like certain dishes have tohave a certain type of rice, you
know, like Mexican food has tobe long grain rice.
So yeah, you learn about therice.
I don't know what you call that.
The appropriate rice type thatyou're supposed to, like a wine,
right?
Like you have a white wine withfish.
SPEAKER_01 (34:20):
A rice sommelier.
SPEAKER_03 (34:22):
There you go.
Oh
SPEAKER_01 (34:24):
my goodness.
That is really impressive.
SPEAKER_03 (34:26):
You can't just have, you know, any rice with any
dish.
Well, I could, but
SPEAKER_01 (34:31):
you're not supposed to.
I think we've just invented anew career and your wife might
be our pioneer.
Well, Luis, thank you.
Is there any sort of event you'dlike to promote?
SPEAKER_03 (34:42):
Well, we have, besides the annual grower
meetings, we have the riceproduction workshop this year.
I think in July, I can'tremember the date exactly.
You know, that's a big event forus.
I know a lot of growers like toattend, a lot of PCAs.
SPEAKER_01 (34:59):
And that's a big one.
That's a two-day event, right?
It's a two-day event.
And this year we're going tohave it July 23rd and the 24th.
SPEAKER_03 (35:07):
Yeah.
And so it's going to be in Davisthis year.
It might be a little out of theway for some of the northern
counties, but we're making it alittle bit more available to the
southern counties there.
So we'll see.
SPEAKER_01 (35:20):
Great.
Okay.
Well, with that, I mean, you'vebeen on here a lot before.
Your contact information isavailable, but you want to say
it again for any of our newlisteners?
SPEAKER_03 (35:30):
Yeah.
If anybody has any questions anyissues um you know they want to
discuss from last year or comingup here for getting ready for
the new for the new season uhyeah give me a call 530-635-6234
and you know you can text and myemail is on on the website on
(35:52):
the internet so yeah
SPEAKER_01 (35:53):
great all right well thank you so much Luis all right
thanks Sarah
SPEAKER_03 (36:00):
so
SPEAKER_01 (36:11):
We have a few upcoming rice meetings in the
new year.
As you know, we'll be having ourrice winter grower meetings in
February.
And so we have a series ofmeetings.
They all have the same agenda.
Don't go to every singlemeeting.
You'll be awfully bored.
But pick one.
Pick the one that's closest toyou or most convenient to you
and attend that one.
(36:33):
So the first one will be thewoodland meeting, which will
take place February 10th at 8a.m.
The location for that will bethe The second meeting will be
the Richvale meeting, which willtake place February 12th at 8
a.m.
The location of that is theRichvale Evangelical Church.
(36:56):
The Willows meeting will be thatsame day, February 12th at 1
p.m., and that location will bethe Glen County Office of
Education.
The Colusa meeting will takeplace February 13th at 8 a.m.
in the CIP conference room, andthe Yuba City meeting will take
place that same day again,February 13th at 1 p.m., and
(37:18):
that'll be in the Veterans Hall.
For more information aboutmeeting times and locations or
addresses and agendas, pleasefeel free to look at our
resources online.
That'll include the UC Rice blogand the UC Agronomy website, or
feel free to call your localExtension Office for more
information.
In terms of other resources thatyou might take advantage of, you
(37:42):
can also look at ournewsletters, which include Rice
Briefs, which covers ColusaYolo, Rice Notes, which covers
Yuba Sutter, Rice Leaf, whichcovers Butte and Glen, and Field
Notes, which takes care of ricein the Delta region of
California.
UNKNOWN (37:59):
Music
SPEAKER_01 (38:09):
Thanks for listening.
(38:39):
We're also experimenting withpolls on Spotify.
So if you're listening onSpotify, you might have an
option to answer some of thosequestions and we might be able
to talk about that on the air.
You can also email us with anycomments, questions, or concerns
at thoughtsonrice atucdavis.edu.
(39:03):
We're glad to have you here forseason two of the Thoughts on
Rice podcast.
And remember, like the growerslike to say, have a rice life.
Mention of an agrochemical doesnot constitute a recommendation,
merely the sharing of researchfindings.
Always follow the label.
The label is the law.
(39:24):
Find out more at ipm.ucanr.edu.
The views, thoughts, andopinions expressed are the
speaker's own, and do notrepresent the views, thoughts,
and opinions of the Universityof California.
The material and informationpresented here is for general
purposes only.
The University of Californianame and all forms and
(39:45):
abbreviations are the propertyof its owner, and its use does
not imply endorsement of oropposition to any specific
organization, product, orservice.
Hello and welcome to Thoughts on Rice, a podcast
hosted by the University ofCalifornia Cooperative Extension
Rice Advisors.
I'm one of your hosts, SarahMarchionish, and I'm a rice farm
(00:21):
advisor for Colusa and Yolocounties.
SPEAKER_02 (00:24):
I'm Whitney from the forest.
I'm the Cooperative ExtensionRice Advisor for Sutter, Yuba,
Placer, and Sacramento counties.
SPEAKER_03 (00:31):
My name is Luis Espino.
I'm the Rice Farming SystemsAdvisor for Butte and Glynn
SPEAKER_00 (00:38):
counties.
I'm Michelle Leinfelder-Miles.
I'm a farm advisor in the Deltaregion.
I work on all sorts of fieldcrops, grains and forages, but
one of those is rice.
And the counties that I coverare San Joaquin, Sacramento,
Yolo-Solano, and Contra Costacounties.
SPEAKER_01 (00:56):
Together, the UCCE Rice Farm Advisors seek to
provide relevant, topical,research-backed information
relating to California riceproduction.
Today, Luis Espino and I get totalk about the results of the
2024 Rice Disease Survey, whichwe compiled this last season.
(01:19):
The objective of the survey isto document the incidence of
rice diseases in SacramentoValley rice fields, so that the
California Air Resources Boardagrees to continue to allow the
rice industry to burn up to 25%of the available rice acreage.
(01:54):
Luis.
Hi,
SPEAKER_03 (01:55):
Sarah.
SPEAKER_01 (01:55):
How are you?
Good.
SPEAKER_03 (01:57):
Happy New Year.
SPEAKER_01 (01:58):
How are you?
Happy New Year.
Happy New Year.
Yeah, all good.
Let's chat about the RiceDisease Survey.
Since 2014, we've performed thissurvey every five years.
And when I say we, I meanUniversity of California
Cooperative Extension.
So can you tell me a bit aboutwhat happened to cause this
disease survey to start?
SPEAKER_03 (02:19):
Yeah.
So, you know, back in the early2000s, we transitioned from
straw burning in any field toonly 25% of the acreage.
And so when that transitionhappened, initially, the grower
(02:39):
had to prove that he haddiseases in the field.
And so they were trained by, youknow, at the time, the farm
advisors.
And then at some point, alsomaybe the ag biologists from the
ag commissioner's offices.
So they would come and inspectthe fields and kind of show that
(03:00):
there was disease and documentthat before they could be
allowed to burn.
So what happened was that everyinspection that was made showed
that, yes, there was disease asexpected, and the fields were
allowed to be burned.
And so at some point, it wasdecided that it would make more
(03:21):
sense to just show the level ofdisease valley-wide and use that
as a proxy of how much diseaseis there in the field.
And so that's why we do it thisway now.
Instead of having the grower,you know, having to certify that
he has disease, having somebodycome to inspect, you know, we
(03:42):
just use the informationgenerated from the survey and
say like, yes, we're stillseeing diseases and burning is a
good way of reducing diseaseinoculants.
SPEAKER_01 (03:52):
Yeah, that seems like that places a lot of burden
on the grower and the agcommissioners to go out and
inspect all of these fieldsprior to allocating a burn
permit.
SPEAKER_03 (04:02):
Right.
SPEAKER_01 (04:03):
It seems like the Rice Disease Survey is a lot
more efficient.
SPEAKER_03 (04:06):
Yeah, I think it serves that purpose.
And it also, I think it gives usfarm advisors and specialists,
people working on rice, gives usa good overview of what's going
on in the field and how muchdisease is out there.
SPEAKER_01 (04:21):
Absolutely.
Really valuable informationcoming out of the disease
survey.
Let's go into the methodology ofthe disease survey itself.
What does it look like when wedo the disease survey?
How long does it take?
How many counties?
How do we decide how muchdisease is in our rice field?
SPEAKER_03 (04:38):
What we do is in drain time.
So late August, early September,we start the survey because
that's the time when we're goingto see the diseases most
severely affecting the rice.
So they're easier to identify.
And so what we do is we take ateam of anywhere between five,
(05:01):
six, seven scouts and we just goacross the valley and we have a
number of fields that that weneed to inspect and so for the
large counties like you knowrice growing counties like
colusa glen butte we do 10fields and then for the medium
(05:22):
size we do five and then for thesmaller counties you know like
maybe sacramento or placer wejust do two fields and and those
numbers are so of arbitrary youknow but I think they they give
us a good idea of geographicallyit kind of show up real nice on
the map so it gives you a gooddistribution of of the fields in
(05:46):
the map and so we go to fieldsyou know that we have a number
of fields and we just randomlychoose fields we go into these
fields and every one of thescouts goes in and then we do a
certain number of stops in thefield, and on each stop, the
scouts would look for the fourmain diseases that we have.
(06:08):
So we look for stem rot,aggregate sheath spot, kernel
smut, and blast.
And this year, we did see alittle bit of bacony.
And so we noted that.
Not a lot, but there was, youknow, in the past, we had never
really run into bacony.
So this was the first year thatwe were seeing bacony.
So we noted that as well.
(06:28):
So we then, we just go bypresence, absence.
So we're not really trying toquantify on a stop like how many
tillers show stem rot or howmany panicles have blast.
We just look for presenceabsence.
And so each scout does a numberof stops and we shoot for at
(06:52):
least 30 observations per field.
And so we have 30 observationsand then we move on to the next
field.
And so with that, we can kind ofhave a feeling or we can
calculate a percent incidence ofthe four diseases.
SPEAKER_01 (07:08):
So with all of these stops, I think I read in your
report that there are over 1600individual observations made
across the race disease survey.
So it seems like that's a prettyrobust data set to get an idea
of how much disease is in thearea.
SPEAKER_03 (07:23):
Yeah, yeah, I think so.
And it's interesting becausewe've been doing this now.
This is our third time doing it.
So we do it every five years.
This is the third time we doneit.
And so I've been looking at whatwe did the two previous times
and a couple of diseases, stemrot and aggravation spot, they
are pretty much the same.
(07:44):
The levels that we see have beenvery, very similar.
SPEAKER_01 (07:48):
Interesting.
SPEAKER_03 (07:49):
Yeah.
But blast, for example, which isa disease that varies quite a
bit.
In some years we see more andthis year we only run into a few
fields where we saw one panic ineach field with blast.
So very low levels.
And that's what we've seenduring the season, kind of just
(08:11):
looking around and responding toPCAs and growers calls.
If they were suspecting blast, Iwent to a couple of those and it
was in blast, right?
So we kind of knew that it was alow blast year, but yeah, with
the survey, we know like, yeah,very little blast out there.
SPEAKER_01 (08:28):
It's great though, that you can see immediately
that reflection of how accuratethe disease survey has been, at
least with the blast survey,with the real life results that
we're seeing in the field of notvery much blast recorded in the
disease survey, not very muchblast reported, at least to us
and across the rice growingregion.
SPEAKER_03 (08:46):
Right.
And then with the tillerdiseases, you know, like stem
rot and aggregation spot.
So those, you know, we've talkedabout them at grower meetings
quite a bit.
Those go, the inoculum goes intothe field.
And so you would expect thatthey would be somewhat similar
every year, if not increasingover time, but it doesn't seem
to be increasing.
(09:07):
It's already pretty, they'represent pretty widespread across
the valley.
So yeah, it makes sense thatevery year we find about
roughly, you know, the sameamount of observations positive
for those two diseases.
And the same with Colonel's mud,it varies a little bit, right?
Depending on the year.
SPEAKER_01 (09:27):
Any other differences between this recent
disease survey and the pastdisease surveys in terms of
disease proportions?
SPEAKER_03 (09:35):
I think the main one was blast.
And then that's, you know, thatdepends on the years.
If we would have done the surveyin 2023, which was a blast year,
we would have found it in a lotmore places, right?
But no, everything else, like Isaid, was similar and with the
added of identifying somebacchani here and there.
SPEAKER_01 (09:57):
Let's go over this a little bit.
So we talked about how thisyear, unlike other years, we did
see some more Bacchanet.
And can you explain why weusually don't search for
Bacchanet during the ricedisease survey?
SPEAKER_03 (10:11):
Yeah, it was something we didn't look for in
the past because we didn'treally have Bacchanet levels
that would be identifiable atthat time.
We've seen over the past, Idon't know, now it's been maybe
like four years or so, threeyears, an increase in bacony, I
(10:35):
suspect it comes mostly from areduction in the use of bleach
as a seed treatment.
SPEAKER_01 (10:44):
Because just for people who aren't aware, that's
when we treat for bacony.
Before we fly on our seed, we'llsoak the seed in a bleach
solution for a period of timebefore flying on the seed, and
that can help kill the baconybefore it actually takes effect
on the plant itself.
SPEAKER_03 (11:01):
Right.
It kind of disinfests the seed.
So bacony is transmitted mostlyon the seed.
And so treating the seed withthe bleach really, it's really
effective.
You know, you can have someinstances where you do see
bacony in treated seed, but forthe most part, it's very
unusual.
And so with these, you know,previous years, we were seeing a
(11:23):
little bit more bacony.
It looks like, you know, maybebecause not all seed is being
treated.
So some of what happens is thethe seedlings that get infected
most of them die before theydon't really last past tillering
but there are a few that willsurvive and then those will
(11:44):
develop symptoms towards the endof the cycle and so the plants
just by the time the panicleshould be produced the panicle
comes out but it's blanked andthen the whole plant just starts
dying and you can see thesporulation on the tiller and So
they're kind of easy to identifyonce you see them.
(12:06):
But there's not many of them.
But, you know, it's interestingthat we were not finding any of
those in the past.
And now we're seeing a littlebit.
SPEAKER_01 (12:13):
Yeah.
Going on to that, what do wethen do with the results of the
disease survey?
We've collected all thisinformation.
You've compiled it.
You've made the statisticalanalysis.
But what do we do with it then?
Does it just sit in a drawer ordoes it go somewhere?
SPEAKER_03 (12:27):
Well, no.
So this information then isprovided.
to the Air Resources Board.
We present the information andthey use that to kind of make
the determination that yes, youknow, there's diseases are still
a problem in rice cultivation.
And so we're going to continuewith the burn program and, you
(12:50):
know, letting growers burn up to25%.
That's the main use of theinformation.
So we're getting some otherinformation in terms of, you
know, how widespread some ofthese diseases were and And
also, if there was anything newthat would be starting any new
disease and we started to pickit up on the survey, that would
(13:11):
be also helpful to know there'ssomething that we need to start
doing to prevent something elsecoming to affect us.
SPEAKER_01 (13:19):
Just anecdotally, having done the disease survey
with you and the team thissummer, it was also a great
opportunity to get a look atsome weeds that we were seeing
in the field, just in randomfields that we happened to be
surveying.
some different weeds than wewere usually seeing around rice
fields.
So as far as just getting moreinformation in terms of rice
(13:40):
production, being in the fielditself seemed to be pretty
anecdotally important.
SPEAKER_03 (13:45):
Oh, yeah.
Yeah.
You get to see things thatotherwise you might miss, you
know, because you're not reallylooking.
Something related to that, forexample, we were on a field
where we started to find a lotof army wounds.
That was interesting because youknow, we do the armyworm
trapping and we do monitor forarmyworm.
(14:06):
So we have three or four fieldsthat we monitor through the
season to see what thepopulation is doing.
And we were not finding anyarmyworms at heading.
But when we visited this field,there was a ton of armyworms.
SPEAKER_01 (14:19):
And that's later in the season than we usually see a
lot of armyworms, right?
SPEAKER_03 (14:23):
Yeah.
I mean, they can still be thereat heading.
So brings home the message thatevery field is a little bit
different and you can have a lotof fields with now no armyworms
on them or no disease.
And then there are some fieldsthat for whatever reason, they
will have a lot more pressure.
Always like to think about, youknow, what one of my teachers
(14:45):
said, you know, the best thingyou can put in your field is
your shadow because you have tobe in your field to know what's
going on.
SPEAKER_01 (14:52):
I like that.
That's really, really importantbecause, yeah, you can see
things from your truck, from theside of the field, but the
reality is you You're not goingto see the full picture.
SPEAKER_03 (15:03):
Yeah, or just hearing, you know, what's going
on, like the neighbors or if theACAs are saying, oh, we're not
seeing any of this, but younever know.
It's always good to go and takea look.
SPEAKER_01 (15:14):
So in the recent disease survey, we saw different
diseases that were prevalentacross the region and actually
saw higher incidences of some ofthe diseases in specific sub
areas.
And so, for example, we saw thatGlenn County actually had the
highest incidence of stem rot.
So can you explain why thedisease presence might be higher
(15:35):
in some areas versus others?
SPEAKER_03 (15:36):
Well, you know, there are some differences in
terms of weather.
Up north, it tends to be alittle warmer.
Glynn County can have a littlewarmer weather than some of the
southern part of the valley.
And so that can be acontributing factor.
I don't know if there's really avariety effect.
(15:57):
You know, I haven't looked atthe acreage of the different
varieties per county or regionso I don't know if that would be
but my guess is it's probablymostly weather related and so
for example we did see more stemrot and typically if this would
have been a blast year we wouldhave seen most of the blast up
(16:19):
on Glen County and Colusa Countybecause those are the areas
where we you know the weatherseems to be more favorable for
blast but also thinking ofanother disease and this is
aggregate sheath spot, which isnot a major disease, you know,
but it's present, it'swidespread.
It was a little bit morenoticeable on the east side of
(16:42):
the valley, which we know that,you know, it's soil related and
related to potassium.
And so some of the soils on theeast side tend to be more
deficient on potassium justbecause of the type of clay that
they have.
And so we tend to see a littlebit more of aggregate sheath
spot.
SPEAKER_01 (17:01):
Okay.
So I guess two of these diseasesthen, and you've mentioned them
already, but stem rot andaggregate sheet spot can
actually be pretty highlyinfluenced by agronomic
practices, which can includefertility, like added fertility
and straw management.
Can you touch on a little bitabout how these agronomic
(17:22):
practices can influence thedevelopment of these diseases?
SPEAKER_03 (17:26):
Yeah.
So I think, you know, for thetiller diseases, yeah, there's
nitrogen certainly has a astrong effect on stem rot.
And unfortunately, you know, weneed nitrogen and we need
nitrogen to reach our yields,you know, the optimal yields.
(17:47):
But the more nitrogen you addmakes the plants more
susceptible to stem rot.
So in some cases, it's kind ofhard to avoid, you know, you're
not going to reduce yournitrogen just to have less stem
rot.
Right.
But I think it's important tokeep mind because you know you
don't want to do you know addnitrogen as thinking of well
(18:10):
maybe just as an insurance orwithout properly assessing the
need of the of the crop rightlike you know if you're going to
use a top dress well maybe goout and use the leaf color chart
and and make sure that you doneed it with aggregate sheet
spot it's more related topotassium and so if you have a
(18:33):
Potassium deficiency aggregationcan be problematic.
I wouldn't say a major problem,but it can be problematic.
And it's similar for stem rot.
So stem rot can also be moresevere when there's a potassium
deficiency.
And so potassium, it's a veryimportant nutrient.
(18:56):
And I think most of the growersand the PCAs on the east side
know that very well becausethey've seen it.
But a lot of times on the Westside, we're not so aware of it
because we've always thoughtthat we have plenty of potassium
and that deficiencies will notoccur.
But we've seen the potassiumdeficiency symptoms on the West
(19:18):
side.
And, you know, it could be justthat the information about, you
know, having enough potassium,it's from quite a few years
back.
And so the varieties aredifferent.
Our yields are higher, you know,than say 30 40 years ago our
yields are much higher so we'reextracting quite a bit more so
(19:38):
so yeah we've seen potassiumdeficiency symptoms on the west
side so it's something that it'simportant to keep in mind that
review your your soil fertilityyou know add soil sample leave
sample and make sure that youhave enough in there because it
not only affects the plantsdirectly but then you can end up
(19:59):
with more disease level moredisease pressure by not
addressing the fertility.
And then blast also is relatedto nitrogen.
So the same as with stem rot,you know, if you have too much
nitrogen, then your blast can bemore severe.
But that's another one where,well, you know, we need the
(20:20):
yield, so we can't really cutdown much on nitrogen.
SPEAKER_01 (20:24):
Yeah, you can't tell someone, hey, you might have a
disease next year, so cut backon your nitrogen.
That's not going to fly.
Is there data to suggest thatthat the reduction of burning of
rice straw has influenced therate of potassium available in
the soils?
SPEAKER_03 (20:40):
I don't
SPEAKER_01 (20:40):
think
SPEAKER_03 (20:40):
anybody's looked at
SPEAKER_01 (20:41):
that.
I feel like it'd be hard to testthat.
SPEAKER_03 (20:44):
Yeah, I mean, you would have to go back in time
and find some soil samples.
And there might be some, becauseBruce did some work just
recently on potassium levelsacross the valley.
So that information isavailable.
And I know there is someinformation, I I can't remember,
but it's some of the work that Ithink Scardacci did.
(21:06):
And I think he looked atpotassium.
There's something floatingaround there.
So one could look, go back andlook at and compare levels, but
I don't know how scientific thatwould be because not the same
fields,
SPEAKER_01 (21:18):
not a lot of control in that.
SPEAKER_03 (21:20):
Right.
But it would be an interestingexercise.
Yeah.
I started working on rice herein California in 2007.
And, you know, I worked them,but with, with Chris Greer, uh,
Chris was a plant pathologist,and so I helped him with some of
his work, and we would do somefungicide trials.
(21:40):
And it's interesting because hedid trials at least for a couple
of years, and we couldn't findan effect on...
Basically, we were testing aquadris or a soxistropin, and we
didn't see an effect on thetiller diseases.
SPEAKER_01 (21:56):
Interesting.
SPEAKER_03 (21:57):
And then he moved out of the area, and so we
really didn't...
do any work for a few yearsuntil maybe 2018 or 2019 when I
started doing again.
After having quite a bit ofgrowers coming with disease
issues, I started doing thetrials again.
And then we started seeing astrong effect of asoxystrobin on
(22:20):
the tiller diseases.
And so that might be related tothe burn over the years as we've
stopped burning.
We might be increasing ourinoculum levels to the point
where in the past, there wasn'tenough disease to show an
effect.
SPEAKER_01 (22:38):
But now there's higher levels of disease and
then the azoxystrobin.
SPEAKER_03 (22:41):
Yeah, maybe with this body.
So you would pick it up here,but not there.
But now after, you know, almost20 years of no burning, we do
see an effect.
I mean, it's, yeah, and it'sreally obvious.
SPEAKER_01 (22:54):
While we're talking about straw anyway.
So the pathogens that cause therice diseases, the tiller
diseases, they can actuallyoverwinter in the rice straw in
the form called sclerotia.
And that can actually survive inthe tissue and accumulate in the
soil over time.
Is there another way besidesburning to reduce the survival
(23:17):
of the sclerotia in the ricefields?
SPEAKER_03 (23:20):
Yeah.
So the sclerotia, you know, theywill remain on the rice.
And then early in the spring,when it starts warming up, you
know, say March, April.
So those sclerotia willgerminate and they'll use the
rice straw as a food source andthen produce more sclerotia,
(23:44):
produce more inoculum.
And so if you decompose the ricestraw so that it's not
available, then you can reducethat increase that we get, not
during the season, but later,after during the fallow period.
(24:05):
So that's why it's important toget, you know, if you're not
burning, to try to get gooddecomp, because that's limiting
how much inoculum is beingproduced in the field.
SPEAKER_01 (24:14):
So a method, maybe flood, stomp the field, try and
get that straw to decompose.
SPEAKER_03 (24:20):
Yeah, anything you can do to promote straw
decomposition will help.
Of course, burning is the best.
And if you reduce the amount ofstraw in the field, so if you're
baling, that will would also, wecan say, theoretically help.
But I don't think we have anyactual data to prove that baling
(24:41):
helps.
You know, when you bale, you'restill leaving half the straw
behind.
You can't cut it all the way tothe ground.
And there's always going to besome straw.
Just like when you burn, youalso, you know, there's always
some left behind.
But yeah, but you're reducingthe amount of substrate that,
you know, the pathogen will haveto increase more inoculate, to
(25:03):
produce more inoculum later.
SPEAKER_01 (25:04):
Is there evidence to support the survival of the
sclerotia in the baled strawbales that come off the field so
that if they were broken up,they could potentially spread
disease somewhere else?
SPEAKER_03 (25:19):
I guess they could.
There's some work from BobWebster, who used to be the
plant pathologist at UC Davis,and he determined that the
half-life of the sclerotia istwo years.
SPEAKER_01 (25:33):
Wow.
Wow.
SPEAKER_03 (25:33):
Yeah.
So yeah, if there was sclerotiain the rice straw, and you know,
that that straw is movedsomewhere else, I guess they
could survive.
SPEAKER_01 (25:42):
Theoretically, theoretically, yeah.
SPEAKER_03 (25:44):
Yeah.
But you know, as long as they'renot put back in the rice field,
you know, it would be
SPEAKER_01 (25:49):
doesn't really matter.
SPEAKER_03 (25:51):
Yeah, it wouldn't be a problem.
SPEAKER_01 (25:53):
Okay, so we spent a lot of time talking about the
diseases.
And I want to note here, wehaven't talked a lot about
control of the diseases inseason and a point of that, I
think, comes back to apresentation I saw you make a
few months ago, where you weretalking about disease
management.
And then the next slide wasquadris management.
(26:15):
Because in California, we don'thave a lot of chemicals we can
use to control rice diseases.
Would you like to touch on, Iguess, the availability or lack
of availability of chemicalcontrol of rice diseases in
California?
SPEAKER_03 (26:29):
Yeah.
Yeah, we don't have really a lotof fungicide We really have two,
you know, we have azoxystrobinand it does work and we do have
propiconazole and that one, it'sonly for Colonel's mud.
So yeah, those two fungicidesare available for the rice
(26:51):
industry.
And so it's important to usethem, you know, correctly.
You know, the timing is veryimportant, especially for blast
and Colonel's mud and and stemrot.
I found that aggregate sheetspot, you know, the timing is
not so critical.
We tend to get control even ifyou put it on too early.
(27:13):
But if you go either too earlyor too late with stem rot, you
don't get as good control.
It has to be very early heading.
That's when we get the bestcontrol for stem rot.
And with blast, it's similar.
We get it, you know, the bestcontrol is early heading, maybe
starting from late boot to earlyheading that that might be a
(27:35):
good time and then when you'reif you're thinking of kernel
smart kernel smart the timing isgoing to be uh at the at the
boot stage so if you go too lateif you go early heading that's
that's too late for for kernelsmart so it's a little you know
it could get a little confusingbut so i think you know when
we're talking about diseasemanagement it's between the uh
(27:59):
the boot stage maybe mid boot tothe early heading stage that's
That's the window for fungicideapplications.
And then, you know, it'schallenging because a lot of
these diseases like blast andkernel smut, we don't see them
at that time.
SPEAKER_01 (28:13):
Right.
SPEAKER_03 (28:14):
At least with blast, if you've seen leaf blast, then
you have something to go on.
It's like, okay, yeah, we needto do a treatment because we
might get some neck blast.
But with kernel smut, it'stricky because, you know, kernel
smut
SPEAKER_01 (28:27):
doesn't...
You can't even see the kernelsyet.
Yeah.
SPEAKER_03 (28:29):
Yeah.
It doesn't show until thepanicle is mature So you really
have to go with the history ofthe field, you know, and the
area.
If kernel smut's been a problemin the past, you know, then you
might decide to do a treatment.
Now, with the Taylor diseases,you can do an assessment in the
field to see how much you have.
(28:50):
And we're doing some work onthat.
And I think we have some datathat shows that, yeah, you can
relate, especially stem rot.
We haven't had enough fields ofaggregations, but to make
conclusions.
But stem rot, You can go in atthe boot stage and make an
assessment of how much stem rotyou have and predict how much
you're going to have at the endof the season.
(29:11):
And so make a decision as to, isthis going to really affect the
yield or not?
So we're going to do that againthis year.
And based on that, maybe here inthe future, we can come up with
a more systematic way ofdetermining stem rot levels
before the end of the season.
(29:32):
That's when you really see thestem rot cause the effects on
the plant.
SPEAKER_01 (29:36):
Wow, that sounds like there's some interesting
things in the pipeline.
SPEAKER_03 (29:39):
Yeah, and it might help also make decisions.
If you see that you're havinghigh levels of stem rot, you
might try to get that fieldburned.
Now, you don't have to make thatdecision very early.
You can wait till we harvest.
Or you can make decisions aboutwhat variety you want to have
(29:59):
there.
So we know that varieties thatthat have very short periods of
development tend to be moresusceptible.
And, you know, the stemmer willbe more severe in varieties
like, you know, M105 or thesweet rice.
And so you might want to go witha 209 or 211.
SPEAKER_00 (30:18):
401?
SPEAKER_03 (30:19):
401, yeah.
After last year, I don't know ifanybody wants to go with a 401.
SPEAKER_01 (30:25):
But we'll see how much agar just planted next
year.
SPEAKER_03 (30:27):
Yeah, yeah, we'll see.
SPEAKER_01 (30:29):
I mean, we've been talking about this this whole
time.
We've only got these...
basically four diseases inCalifornia rice.
But in the Mid-South region,they deal with a lot of
diseases.
The insect problems too, but alot more diseases compared to us
all the way out here.
Can you talk a little bit aboutwhy there's so much of a
difference in the two geographicregions?
SPEAKER_03 (30:50):
Yeah, I think the main reason is the weather.
So we have our nice dry summerwith no rainfall.
SPEAKER_01 (30:59):
I've told people that out there, they cannot
believe it.
And I tell them the rain stopsand then it doesn't start again
until Thanksgiving and theythink I'm lying.
But it's true out here.
SPEAKER_03 (31:32):
Probably the fact that we're somewhat isolated,
you know, we're not near any ofthe southern states that produce
rice might help us too.
You know, we don't have thingscoming, get being introduced,
you know, or the risk of thingsgetting introduced is lower.
And, you know, if you thinkabout it, the only diseases that
(31:53):
we currently have that kind ofwere here all along are the
tiller diseases.
Blast was introduced sometime inthe 90s.
Kernelsmod I think it was firstfound sometime in the 80s.
So yeah, we just don't have theconditions that diseases or
pathogens like.
You know, another thing is Ithink the industry has been
(32:14):
really smart in making sure thatany materials that come into
California, any rice seed thatcomes into California, there's a
protocol that has to befollowed.
You know, it has to go in thegreenhouse first, make sure that
there's nothing on it that wouldbe harmful to the industry.
And so I think that's that helpstoo in reducing the risk of
(32:36):
getting something introduced.
SPEAKER_01 (32:38):
We had Timothy Blank on here a while ago talking
about the Rice Quality AssuranceProgram, the Seed Certification
Program, and part of therationale behind those programs
was also maintainingdisease-free, weed-free seed.
And so there's been a lot ofindustry effort focused on
maintaining the quality of riceseed in California.
SPEAKER_03 (32:59):
Yeah, and that's another very important Yeah, I
know Timothy won't let a fieldthat's full of, say, blast or
backening, you know, to be aseed field.
So, yeah.
SPEAKER_01 (33:11):
Well, Luis, I think we're about done with the
lecture part of our talk, but Ijust started doing something
recently and I had poor TimJohnson was my first
experimental person on thisquestion, but you get to be the
second.
SPEAKER_03 (33:25):
Okay.
SPEAKER_01 (33:26):
What is your favorite rice variety to eat or
consume in some fashion?
SPEAKER_03 (33:32):
So, So my favorite type is medium grain rice.
SPEAKER_01 (33:36):
That's a good answer.
SPEAKER_03 (33:37):
Yeah.
Now, my wife, though, she likesmore the basmati, which we don't
eat all the time, but she tendsto favor the long grains and I
tend to favor the medium grains.
Whenever I buy the rice or I geta sample, I buy medium, you
know, I get medium grain andthen we eat medium grain.
(33:58):
And, you know, to me, I can eatanything with rice, but for her,
is like certain dishes have tohave a certain type of rice, you
know, like Mexican food has tobe long grain rice.
So yeah, you learn about therice.
I don't know what you call that.
The appropriate rice type thatyou're supposed to, like a wine,
right?
Like you have a white wine withfish.
SPEAKER_01 (34:20):
A rice sommelier.
SPEAKER_03 (34:22):
There you go.
Oh
SPEAKER_01 (34:24):
my goodness.
That is really impressive.
SPEAKER_03 (34:26):
You can't just have, you know, any rice with any
dish.
Well, I could, but
SPEAKER_01 (34:31):
you're not supposed to.
I think we've just invented anew career and your wife might
be our pioneer.
Well, Luis, thank you.
Is there any sort of event you'dlike to promote?
SPEAKER_03 (34:42):
Well, we have, besides the annual grower
meetings, we have the riceproduction workshop this year.
I think in July, I can'tremember the date exactly.
You know, that's a big event forus.
I know a lot of growers like toattend, a lot of PCAs.
SPEAKER_01 (34:59):
And that's a big one.
That's a two-day event, right?
It's a two-day event.
And this year we're going tohave it July 23rd and the 24th.
SPEAKER_03 (35:07):
Yeah.
And so it's going to be in Davisthis year.
It might be a little out of theway for some of the northern
counties, but we're making it alittle bit more available to the
southern counties there.
So we'll see.
SPEAKER_01 (35:20):
Great.
Okay.
Well, with that, I mean, you'vebeen on here a lot before.
Your contact information isavailable, but you want to say
it again for any of our newlisteners?
SPEAKER_03 (35:30):
Yeah.
If anybody has any questions anyissues um you know they want to
discuss from last year or comingup here for getting ready for
the new for the new season uhyeah give me a call 530-635-6234
and you know you can text and myemail is on on the website on
(35:52):
the internet so yeah
SPEAKER_01 (35:53):
great all right well thank you so much Luis all right
thanks Sarah
SPEAKER_03 (36:00):
so
SPEAKER_01 (36:11):
We have a few upcoming rice meetings in the
new year.
As you know, we'll be having ourrice winter grower meetings in
February.
And so we have a series ofmeetings.
They all have the same agenda.
Don't go to every singlemeeting.
You'll be awfully bored.
But pick one.
Pick the one that's closest toyou or most convenient to you
and attend that one.
(36:33):
So the first one will be thewoodland meeting, which will
take place February 10th at 8a.m.
The location for that will bethe The second meeting will be
the Richvale meeting, which willtake place February 12th at 8
a.m.
The location of that is theRichvale Evangelical Church.
(36:56):
The Willows meeting will be thatsame day, February 12th at 1
p.m., and that location will bethe Glen County Office of
Education.
The Colusa meeting will takeplace February 13th at 8 a.m.
in the CIP conference room, andthe Yuba City meeting will take
place that same day again,February 13th at 1 p.m., and
(37:18):
that'll be in the Veterans Hall.
For more information aboutmeeting times and locations or
addresses and agendas, pleasefeel free to look at our
resources online.
That'll include the UC Rice blogand the UC Agronomy website, or
feel free to call your localExtension Office for more
information.
In terms of other resources thatyou might take advantage of, you
(37:42):
can also look at ournewsletters, which include Rice
Briefs, which covers ColusaYolo, Rice Notes, which covers
Yuba Sutter, Rice Leaf, whichcovers Butte and Glen, and Field
Notes, which takes care of ricein the Delta region of
California.
UNKNOWN (37:59):
Music
SPEAKER_01 (38:09):
Thanks for listening.
(38:39):
We're also experimenting withpolls on Spotify.
So if you're listening onSpotify, you might have an
option to answer some of thosequestions and we might be able
to talk about that on the air.
You can also email us with anycomments, questions, or concerns
at thoughtsonrice atucdavis.edu.
(39:03):
We're glad to have you here forseason two of the Thoughts on
Rice podcast.
And remember, like the growerslike to say, have a rice life.
Mention of an agrochemical doesnot constitute a recommendation,
merely the sharing of researchfindings.
Always follow the label.
The label is the law.
(39:24):
Find out more at ipm.ucanr.edu.
The views, thoughts, andopinions expressed are the
speaker's own, and do notrepresent the views, thoughts,
and opinions of the Universityof California.
The material and informationpresented here is for general
purposes only.
The University of Californianame and all forms and
(39:45):
abbreviations are the propertyof its owner, and its use does
not imply endorsement of oropposition to any specific
organization, product, orservice.
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