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Hi, everyone. I'm Hayley. Welcome to our first webinar, "Managing Cucurbit Bacterial Wilt
with Row Covers & Perimeter Trap Cropping." I'll invite Mark & Erika to both go ahead
and start their cameras and sound, and we can begin the first part of the presentation.
Hi, I'm Mark Gleason and right there next to me is Erika Saalau-Rojas. And we're gonna
get started with this presentation now. Everybody see that okay? Okay, well, tonight we want
to talk about Managing cucurbit bacterial wilt with row covers & perimeter trap cropping.
This is part of a set of results from a team at Iowa State University, Penn State University,
and University of Kentucky, and many of the scientists that have been involved with these
projects are online in the webinar tonight, so questions can be answered by any of those
folks. So over the next 50 minutes or so, we'll talk first as Hayley said about this
one strategy for bacterial wilt control: delayed removal of row covers; and take questions
& answers. Followed by a presentation on perimeter trap cropping, and then again questions & answers.
So that's kind of our format. Just to put some names here to voices, or maybe little
thumbnail pictures that you'll see of people: at Iowa State, as you've already seen us,
Mark & Erika. We also have Donald Lewis and Laura Jesse online from Entomology, so we're
covering plant pathology and entomology there. From Penn State we have Shelby Fleischer who's
an entomologist there, and Elsa Sánchez from horticulture. University of Kentucky: mark
Williams from horticulture there is on, as well as Ric Bessin from entomology. And from
Ohio State we have Celeste Welty in entomology, Mary Gardiner in entomology, Sally Miller
from plant pathology. So that's kind of our cast. Okay, let's just think about the crops
that are affected by bacterial wilt. They're in this group the cucurbits. One of these
that I'm showing here is really not a host of bacterial wilt, and that's watermelon.
But everything else I'm showing here: the butternut, or the winter squash, the cucumber,
the muskmelon, pumpkin, even summer squash, they're all hosts of bacterial wilt. So it's
a disease that we worry about in a wide range of cucurbit crops. Tonight our purpose is
to give you an update on the research that we've been doing, and hopefully list some
applications that are available now or will be in the near future. So now, Erika's gonna
take over and talk a little bit about an introduction to bacterial wilt and the row cover strategy.
All right, Good night, everybody. Thank you, Hayley. And thank you, Mark, for the introduction.
I'm very excited to be here and participating in this webinar. And before we go into the
details of row covers and how we have used them against bacterial wilt, let's review
some characteristics of the disease. So, bacterial wilt is caused by a bacterium called Erwinia
tracheiphila. And this is a vascular pathogen, meaning that it invades the vascular system,
or specifically they xylem vessels of cucurbit crops that Mark mentioned previously. It is
transmitted by cucumber beetles, both the spotted and the striped cucumber beetles.
And, all of those that are familiar with cucurbits, I can assure you that you've seen these in
your fields pretty much every season. The main vector of bacterial wilt, and the one
that we know the most about, is the striped cucumber beetle, which is on the right-hand
side of the picture. Beetles can carry, or harbor, the bacteria in their digestive system.
And when they feed on cucurbit plants, that's when they transmit the pathogen into the plants,
and eventually the plants wilt and die. Transmission mainly occurs through the leaf. And this is
one of my all-time favorite pictures because it illustrates all the factors present in
order for disease to occur. We have a beetle that has been overwintering , that harbors
the bacteria in their digestive system. And these black dots that I'm highlighting with
my mouse are beetle poop--or, the polite way of calling them, 'frass,' and they are infested,
or covered, packed with bacteria or the pathogen, Erwinia tracheiphila. And when the frass comes
into contact with fresh feeding wounds that I'm highlighting here, that's how the pathogen
enters the vascular system. And once in the vascular system, that's when it causes the
wilting symptoms. Interestingly, and this is something that we did not know about until
2010, some Penn State researchers found that another way that the pathogen can enter the
vascular system of the plants is through frass, or beetle poop, deposited directly onto the
cucurbit flowers or the blossoms. Once inside the vascular system, the bacteria multiply.
And symptoms can appear anywhere in between a couple of days or 1 or 2 weeks. And that's
just a close-up of what the bacteria look like inside the xylem system, or the vascular
tissue. On these two pictures, these are two different stages of a disease on muskmelon.
So, on the left you have the beginning, or the onset, of the symptoms. On the right (inaudible),
that's a plant that's on it's way out due to bacterial wilt infection. Plants infected
with bacterial wilt rarely recover. And it may start as wilting, or sort of plants that
look drought-stressed. They don't recover and they eventually collapse; although, the
symptoms may vary with the crop. Some, the result is the same: the plants die. On the
bottom picture that just appeared, here is a picture of a zucchini plant also infected
by bacterial wilt. Now, it's important to mention that in cucurbit crops there's all
sorts of root diseases and also other insect pests that can show similar symptoms to bacterial
wilt. So, to confirm the disease, make sure that you inspect the plant properly and that
you check specifically the base of the plant to make sure that there's not another pathogen
or insect issue that could be causing similar, confusing symptoms. The bacterial wilt is
a disease that we have seen in more of the Midwest and more of the northeastern part
of the country. This circle here depicts the regions or the states where bacterial wilt
is an issue, and although the disease has been detected or reported elsewhere, this
is the highest risk zone--or where growers struggle the most with this disease. This
is a representation of the risk period for bacterial wilt, and on the bottom we are depicting
the season, or the early season and later into the season. And on the y-axis, or the
vertical axis, we have the risk of bacterial wilt infection. And, in general, the highest
risk period for bacterial wilt infection is early in the season. And, 'why is that?' Well,
there are several reasons. Number 1: we have overwintering beetles that are already carrying
the pathogen, or the bacterium, inside their digestive system. And these beetles become
active as soon as the temperatures, or air temperatures, reach about 70-75 degrees fahrenheit.
At the same time that these beetles are active, this is when we're putting our transplants,
or cucurbit plants are emerging. And these beetles are very very good at locating cucurbit
fields and colonizing them very quickly. So once you have the cucumber beetles in your
field, they're already feeding and potentially transmitting the pathogen. Later in the season,
although you can still have bacterial wilt outbreaks, there is a decreased risk of infection.
And this is most likely due to an increased resistance of the plants. So as plants grow
and they mature, they're less susceptible to the disease. So, "what do growers do now
to control bacterial wilt?" Now, there are several options, and one is to delay planting
date. And, the picture that I showed before, is showing the highest risk period. So one
way of preventing bacterial wilt transmission is by skipping that flush of overwintering
beetles, meaning that you would avoid the highest risk period during the springtime,
and have a lower risk of bacterial wilt transmission. One of the setbacks to the strategy is that
it can also delay harvest. So prices, or premium prices in the market, mid-summer or early
in the summer, may be lower if you choose to delay harvest. Conventional, uh, in a conventional
cropping system, meaning conventional or synthetic pesticides and fertilizers, the most common
tool is to control the beetles using insecticides--mainly, neonicotinoids, and also pyrethroids. Some
of the problems associated with the use of insecticides is the beetle pressure can trigger
multiple sprays, and it is, there's a risk of damaging pollinators--both honey bees and
wild pollinators. Also the health hazards associated with pesticides, specifically the
risk associated to the applicators, and the fact that these insecticides can be costly.
Organic growers have fewer options, and this is mainly because insecticides, organic insecticides
against cucumber beetles, can be very pricey. And they're often ineffective. In some cases,
and this is a comment that we've heard from some growers, is that they just, that growing
highly susceptible crops, cucurbit crops, is just not a feasible option. And they might
decide to go with other crops instead of cucurbits. How can row covers help to control bacterial
wilt? Well row covers are not new in the vegetable and fruit crops. And, when we talk about row
covers during our field trials, we're talking about non-woven, breathable fabric, that's
made out of poly-propylene. Some of the benefits of row covers, are not only that they enhance
earliness. They warm up the soil and the air temperature so that plants develop almost
like in a micro-climate or a greenhouse-like climate under the cover. They also provide
protection against harsh weather conditions like rain, frost; and in the case of bacterial
wilt we've been exploring the added benefit that it provides a physical barrier against
cucumber beetles that could potentially feed on plants and transmit the bacterial wilt
pathogen. Row covers, in order for them to be effective, we have found that they have
to be placed over the rows immediately after transplanting, so you really don't want to
leave any chance for those beetles flying around to get in contact with the plant. More
commonly, how we use the row covers, is we place them over wire hoops so that the plants
are not damaged by high temperatures or by the row cover itself. Early trials of, in
Iowa, versus bacterial wilt gave us some very interesting and promising results that, when
we use row covers and remove them at the start of flowering, or female flowering to be more
specific, they showed moderate bacterial wilt suppression. However, bacterial wilt was not
managed, or was not controlled throughout the entire season. By removing the row covers
ten days later, after the start of flowering, we found that this was a much more effective
strategy to suppress bacterial wilt all season long. This led to a collaboration, a multi-state
project, with Iowa, Kentucky, Pennsylvania. And, in the previous trials that I just mentioned,
we were managing bacterial wilt in a muskmelon system, in a conventional cropping system.
So from 2009 to 2012, this collaboration funded by the Organic Research Education Initiative,
we explored the uses and the different timing of row cover strategies, and an organic cropping
system to protect against bacterial wilt. We focused mainly on muskmelon and also winter
squash--in this case, butternut squash. And the first thing that we found out is that
we had regional differences in bacterial wilt risk. Both in Iowa and Pennsylvania, we found
that varying beetle populations, or varying beetle densities, led to sporadic disease
outbreaks or just light outbreaks of bacterial wilt. That is not the case in Kentucky, where
longer higher temperatures and a longer season maintains the beetle pressure constant and
high beetle numbers throughout the entire season. And now some of our results, from
the OREI trials. I want to focus on muskmelon first. And, mainly, what we've found from
our field trials, is that both in Iowa and Pennsylvania, by removing the row covers 10
days after the beginning of flowering, we got very effective or very good control of
bacterial wilt. On average, we had 30% less bacterial wilt in these beetle trials just
by this 10-day removal in comparison to an uncovered control. In Kentucky, and this is
associated to the high beetle population, sorry, the beetle pressure, we found that
removal at the start of flowering was the best option for bacterial wilt control. And
removal at the start of flowering is what growers that are already using row covers
are most likely to do, or, that's when they decide to remove the row covers, traditionally.
In butternut, we also have had different timing of removal, but we've found in all 3 states
that removing the covers at the start of flowering gave the most consistent results in terms
of bacterial wilt control and also yield. So there was not really a benefit specifically
against bacterial wilt in delaying the removal of the covers. Now, one of the benefits of
having those covers, and an added benefit, is issues with squash bug; which seem to be
more of an issue in some of our locations and some of our field trials than bacterial
wilt. Now, you must be wondering, what happens after I remove the row covers, specifically
in locations where there is high beetle numbers or high beetle densities throughout the season.
Well, we trigger our insecticide applications based on scouting. And scouting can be done
directly--walking through your field and observing beetles on plants--and also with sticky cards,
or monitoring cards in beetles. In general, we have a threshold, which if one beetle per
plant is observed in the field, that means that you should take some sort of control
measure whether this is a conventional or organic insecticide spray to control the bacterial
wilt. Conventional products, more commonly what we used after the row covers were removed,
synthetic pyrethroids. And in the case of organic production, we used Surround, which
is kaolin clay, and also an organic insecticide called Entrust with an attractant that's called
CideTrak-D. And, this is based on the scouting, what some of the products or some of the management
strategies that we employed after the row covers came off. Some of the take-home points
from the OREI project are that row covers can help to control bacterial wilt, and they
can control bacterial wilt effectively without the need of multiple insecticide applications;
however, the timing of removal might depend on the geographic region and also on the crop.
So, to summarize, in muskmelon, the best treatment against bacterial wilt was removing the row
covers 10 days after the start of flowering. And this was also the case in Pennsylvania.
So this is the best strategy for both Iowa and Pennsylvania. However, in Kentucky, the
best removal strategy was at the start of female flowering. In the case of butternut
squash, the row cover removal at the start of flowering gave the best results, and this
was consistent in all of the states. In all 3 states. Finally, based on the information
that we've gathered, and our experiences out in the field, it leaves several interesting
questions, and new directions that we want to explore like how can we cut down the row
cover labor and expense. One option, and this is something that we're going to look into,
is how can we mechanize the handling or the use of row covers. And another question is,
'can we replace the non-woven row cover by a much more durable material such as woven
mesh?' And we're going to look into this in 2014 and the coming years just to lower the
expenses on the row cover and make it more feasible for growers. And also another question
is 'how to secure the row covers.' And traditionally, what we have done in Iowa, is we bury the
sides of the row covers under the soil. But we want to evaluate other alternatives that
are in the market, like, for example, can we use sand bags to pin down the row covers?
Tubes of river rock is something that has been used in field trials in Kentucky. Water-filled
lay-flat. And also, pegs or ground staples. So these are all things that we're working
on to see if we can make row covers more feasible and more cost effective for growers. With
that: that's a brief summary of row covers and our experiences, and before we move on
to perimeter trap crops, another alternative to manage bacterial wilt, I would love to
handle any questions or have the panel participate and handle any questions you may have.
Okay, thank you, Mark & Erika. Everyone, we'll now begin our first question and answer session.
Our question & answer panel, if you could all please turn on your audio and your video
that would be wonderful. I will go ahead and start with our first question
from Blane in Ohio. He asked about delayed row cover removal. He says, 'How delayed?
And what are the specific dates in Ohio?' Sorry, what was the rest of it? I missed your
last part there Hayley. What are the specific dates in Ohio? And I
think, more specifically, Northeast Ohio. Well, I'll be willing to chime in on that.
Okay. We've got ten minutes for our Q&A here, so I've got the timer going.
So we start seeing Spring activity about 150 to 200 degree-days counting from January 1st
with a base of, I think it's 55 fahrenheit. So, that , depending on the temperatures that
year, that's when we start seeing activity. So, in your farm, or farmscape, or surrounding
landscape, if you have cucurbit crops planted about that time, and I can tell you in central
Pennsylvania that's about the last week of May until through the first week of June,
they'll end up picking up most of the overwintering adults that are active. So, in central Pennsylvania,
plantings that happen the last week of June, even sometimes the first few days of July,
tends to have much much slower pressure. I don't know if that directly answers your question
in Ohio, but that's what we've experienced in Pennsylvania.
What about the timing of cover removal? Oh, cover removal?
I though it was delayed planting. He asked about cover removal. Cover removal
was Blayne's second question. So she wanted to know about the timing of rowcover removal
in NE Ohio. Do you want to comment, Celeste?
Well, I thought the question was about delayed planting itself, and I would agree with Shelby
that around the 3rd week of June or the end of June is fine. It gets dangerous if you
go much into July, that you don't have enough time to get the crop fully developed. If it's
for when to remove the row covers, I'd say we are more like Kentucky. It depends on the
year. But in central Ohio we are generally more like Kentucky. We have heavy beetle pressure.
And the delay doesn't help as much. In Northern Ohio, some years we just do not have much
pressure. So it sort of depends on the year, whether we're a high pressure or low pressure.
(inaudible) Ajay, is that you, Ajay, speaking?
No, it's not me. I think it's Mark. It's Mark Williams.
Ric Bessin. Mark, can you, can you have a try with your
audio again? I think it's pretty hard to hear for everyone.
Maybe get up to the mic. Yeah.
I was just saying that, I would agree with Celeste (inaudible). Depends on the year.
Okay. Is that sufficient for Blayne's question? Hey, maybe just to add one thing to that,
and that is, one of the issues that came up in our experiment, or field experiment, was
'where to mark the start of flowering.' Because there's two kinds of flowers, for instance
on muskmelon that we were working with there's a male flower, which usually appears earlier,
and then a female, or so-called 'perfect flower' that appears later. And, the beginning of
flowering according to this row cover timing is supposed to start when the first female
flowers appear. Not the first male flowers, but the first female. They have that little
bulge at the bottom below the blossom. That shows that they're female. And that's the
start of what they call anthesis, or where you can start having fruit being fertilized,
so then 10 days after that is when you'd be thinking about removing according to that
10-day delay strategy that was reasonably consistently effective in Iowa and Pennsylvania.
Other questions?
Okay, our 3rd question is from Jeff. He asked if there's a reduction in crop production
from delaying row cover removal 10 days. Well, and maybe the horticulturists wanna
comment here too, but it's not so much a reduction in the yield as a delay in the yield. And,
what we've seen fairly consistently is a delay of about 1 week. If you delay removing the
row covers by 10 days, at the end of the season that costs you about 1 week in terms of the
crop...it's being harvest at about an average of a week later.
Okay, and then our next question is from Robert Beck. 'Will the severe winter effect the beetles?'
I'll be glad to chime in and say, spotted cucumber beetle? Absolutely, yes. They're
gonna get pushed back to more southern locations. Striped cucumber beetle, which is our more,
larger concern here? Yeah, but not so much. If there's not a lot of snow, that'll hurt
them worse. But, the striped cucumber beetle has a good diapause capacity. I'm sure it's
gonna knock them back, but at least here in Pennsylvania I don't think it'll knock them
out of the state or anything like that. Where, in Pennsylvania, it would knock the spotted
cucumber beetle out. So, it'll reduce your pressure, but you still need to be prepared
for the striped cucumber beetle. Okay, our next question is from Mishaga. "In
organic production, should I employ both Surround and Entrust + CideTrak-D?" I hope I've said
those correctly. I guess, I could comment on that. This is
Celeste. We think, you have to be a little careful, those two strategies are sort of
very opposite of each other, so you really should choose either one or the other. Because
the idea with Surround, it repels the beetles. It makes the plants unattractive. The idea
with the CideTrak is it makes the plant more attractive. It's trying to bring the insect
into the poison--the Entrust you want them to eat. So it is better to use one or the
other. The only thing to keep in mind:you are only allowed to use Entrust twice. So
I would starting use Entrust twice, and hopefully that will do the job...the Entrust + CideTrak.
If that doesn't do the job, then switch to Surround later in the season.
Umm, a few comments I'd like to push on that is, so, if you can only use the Entrust a
few times, if you can try and control that early-season first generation, and then do
as much sanitation as you can, and by that I mean pick your crop clean and then if possible
remove it from the environment and when you're done till it under, as opposed to having many
successive plantings of many cucurbit crops. That'll get you kind of a farm-level sanitation
approach that'll help keep the beetle pressure down low later in the season. And the other
is, don't get, don't assume that just because it's an organic insecticide that it's okay
for bees. The Spinosa-type materials, which mix up the active ingredient for Entrust,
and there's non-organic-certified options for that as well, they can be highly toxic
to bees. So, do all the same things we urge conventional growers to do: try and spray
when the flowers are closed and that'll minimize the amount of activity of bees on fresh residues.
I think we can handle about one more question if you have one, Hayley, and then other questions
we can reply to by email after the program. Does that sound okay?
That sounds great. Okay, and we've got one left from Mike Patrick. He's asking, "Do the
beetles overwinter in your garden if you have them?"
the answer is, probably yes. The old literature says they overwinter in sheltered locations,
edges of fields, and I'm sure that's true. We've gone inside of fields and put cages
on top of soil in February, March, and proven to ourselves that they are in the soil, they
emerged from that location. However, the beetles are tracking the cucurbits over time. So,
they're moving around the farm-scape looking for wherever there are cucurbit crops. In
our case, we found them overwintering in old pumpkin fields, or winter squash fields. Pumpkin
fields where people harvested them for face pumpkins and left ones that weren't, you know,
sold. They just left them in the ground, left them kind of rotting there. And we found the
beetles overwintering in there. So if you do some farm sanitation there, try and clean
those cucurbits out of the field. That'll reduce the problem. In a garden setting, you
know, once the zucchinis and squashes aren't doing so well with all the powdery mildew
and stuff, clean it up. And that might reduce any overwintering of that location.
Okay. I guess we can move on then, Hayley, right?
Great. Yep, we'll go ahead and move on. Okay, good. Okay, so, the second subject here
tonight is perimeter trap cropping. Again, we've had some field trial experience with
this we wanted to share with you. Again, the target is trying to suppress bacterial wilt,
same disease we've been talking about. This is giving you a visual of how perimeter trap
cropping, which we're abbreviating 'PTC,' how this is supposed to work. So here we have
a cucurbit field, we have a nearby sort of edge of the field. And we have, really, two
crops grown in the same field under this perimeter trap crop strategy. We have a border crop,
which is typically two rows at the edge of the field, and then we have our main crop,
which is the entire rest of this field. So these are two different cucurbit crops. And
the border crop is designed to be a cucurbit crop that is highly attractive...very very
attractive to cucumber beetles. They want to locate there and they want to stay there.
Whereas the main crop is somewhat less attractive to cucumber beetles. So in the springtime,
as Shelby described and Erika described, the beetles are coming into the field from the
outside. They don't fly very high. They're typically knee-level or thereabouts. So the
first thing they encounter when they come in to the border is that highly attractive
crop, and they tend to stay there and aggregate, or, essentially accumulate in big numbers
right there in the border crop. So, once those numbers get up past a threshold in the border
crop, and you determine that by scouting, the idea is to spray an insecticide on the
border crop to kill those cucumber beetles. So the general idea is that the cucumber beetles
will not pass in any great numbers past the border crop in to the main crop. So you use
that border crop as a barrier, a live barrier, to block or slow the entry of those cucumber
beetles into the main crop. So, that's the concept, and that's what we're testing. The
inspiration for this perimeter trap crop work came from about ten years of work in Massachusetts
with butternut squash as the main crop. This work was done by Ruth Hazzard and her team
at University of Massachusetts and also in Rhode Island by Jude Boucheir. The trap crop
that they used in these experiments was hubbard squash. So this was the double border row
around the main crop of butternut squash. In their experiments, in field trials with
growers on field-scale experiments, these weren't just small experimental-farm experiments,
but rather field-scale experiments, they saved about 90% on the insecticide use compared
to what growers had been putting on to protect butternut squash against cucumber beetle and
bacterial wilt before using the strategy. So it's been a success story in New England
with using butternut squash as the main crop. So with that inspiration, we began a project
in 2011 and 2012 in Iowa and Ohio, to see if that strategy would adapt to our somewhat
different cucumber beetle populations and soils and climate here in the midwest. And
we also tried a different main crop, which was muskmelon. A key, and this is what was
learned in New England, a key is to get the trap crop, those two border rows, planted
in the field first. Usually at least two weeks ahead of when you plant the main crop. So
these young ladies are just about ready to plant that border crop before the main crop
goes in. This is a view of one of our small experimental-scale plots in Iowa in early
summer, and the main crop here is muskmelon. And what you see as a border crop here is
buttercup squash--not butternut or hubbard squash, but rather buttercup squash. It's,
again, highly attractive to cucumber beetles. As you can see, it's a very robust crop, it
grows like a weed, it makes a decent physical barrier as well as that chemically attractive
barrier to the cucumber beetles. The results of these trials, of course cucumber beetle
pressure varies from year to year as we all know, and site to site. But we were impressed
that the cucumber beetles stayed consistently pretty well in the trap crop and only a very
limited number got beyond that into the main crop. And we noticed there was a significant
reduction in insecticide use when we used that perimeter trap crop strategy compared
to a control plot nearby that did not use the strategy. And the yield was not really
affected. But the key thing was the insecticide use by this alternative strategy was reduced.
So in these early adaptation experiments in the midwest, we thought we saw encouraging
evidence that perimeter trap cropping could work. There are some challenges, as there
are with any new strategy. One challenge is trying to manage two crops in the same field.
Because we have not just one cucurbit crop, but two. We have the border crop, which is
one. Cucurbit crop and the main crop which is another one. One challenge obviously is
marketing. Can you market them both? In our case, muskmelon and buttercup. And, of course,
when you have a melon and a squash in the same field, you're going to have to manage
different pests. Particularly for the border crop, the butter cup squash, you have to really
think hard about squash bug, in some places squash vine borer in addition to the cucumber
beetle. So, management is somewhat more complex because you have to think about two crops.
The other issue is getting beyond our small fields, which is where they started in New
England, and scaling up to something that's more realistic farm-size field. And that's
what we intend to between Iowa and Ohio over the next couple of field seasons. We intend
to scale up to a more realistic size. If you're interested in getting more information about
perimeter trap cropping, or even trying it, you can call or email the Iowa State University
or Ohio State University team members. I also recommend a set of tips from the New England
perimeter trap crop gurus, that's Ruth Hazzard and Jude Boucher. These are very practical
tips for growers and they're listed at this URL, which is available online hopefully you
can access. So at that point, we can open it up for questions on perimeter trap cropping
or whatever else is on your mind. Okay. I don't see that anybody has entered
any questions yes. We can hang tight for a couple minutes. Maybe somebody will ask some.
I'll just add some additional comments that we didn't mention. Muskmelon is a challenge
for one reason because it is fairly attractive to cucumber beetles. So there wasn't a lot
of information before we started our work as to what, maybe muskmelon was going to be
too attractive to work as a main crop, but it turns out with that buttercup around it,
the muskmelon main crop was still reasonably well protected. We did not see situations
in Iowa of high pressure, but Celeste mentioned to me that some of the situations in Ohio
State were higher pressure. So they, there were a number of different situations in terms
of beetle pressure that we evaluated. This is all still early work, and more to be done
to really gain some confidence in the reliability of this method. Okay, we've got a couple questions
in now. Blayne has asked, "Would this work in a very small garden?"
Actually, I haven't tried it myself. I think, in theory, I have recommended that gardeners
try it. What I would suggest is to do something like, it has to be a really small scale like
a potted, like say, if you're going to grow six zucchini plants, then take two potted
zucchini plants, I'm saying potted because you could put them out earlier even if there's
a danger of frost; but definitely do the advanced business. You know, put them out in advance
with the idea, and be prepared to chemically or mechanically kill the beetles that get
on them. But, in theory, it should work. You just have to be very vigilant to try and kill
the beetles that come into that trap crop. Other questions there, Hayley?
The next question is from Jeff. He says, "Does it have to be a perimeter, or would a row
work on a small field?" Actually, that's a super question, and something
that the New Englanders have dealt with to some extent. It doesn't have to be a square
plot. Ours were 50 feet by 50 feet, but the thinking is, at least among the New Englanders,
that field shape can be fairly varied. But, it's really important to keep those border
rows intact the whole season. So, if somebody drives a tractor over the border rows or a
bunch of them die from bacterial wilt, that protection is no longer there. The beetles
can charge through that gap and get into the field, and that sometimes happens. So it's
really important to protect the health and vigor of the border row. That's something
we didn't talk about in the presentation, but that's something that the New Englanders
have emphasized to us. Mike Patrick has asked then, "The perimeter
squash is actually pretty crop?" Yes, absolutely. The buttercup, at least in our farmer's markets,
is a fairly marketable crop. Far more so than hubbard squash. Hubbard squash, people look
at it, unless you've backed over it with a car it's really hard to eat it.
Okay, next question. Jeff has also asked "What other trap crops are high value to the beetles
other than hubbard and buttercup?" Well I was gonna say that within the, if you're
familiar with the, you know, the sort of taxonomy of cucurbits, it's anything that's Cucurbita
maxima. So the hubbard squash, and the buttercup squash, are both within that maxima species
as well as Turk's Turban and that, what's it called, Jumbo Pink Banana, and there are
a number of some smaller hub bards, not just the big New England hubbards. But anything
that is cucurbita maxima is generally considered to be the most attractive to beetles. I'd
recommend against Turk's Turban, because it's so susceptible and it's so attractive that
it gets totally beetle-covered and dies in a heartbeat. One of the good things about
hubbard and buttercup is they're fairly robust plants and they don't go down as fast as Turk's
Turban. Okay. Well, we have no other questions. If anybody has any comments, go ahead and
go for those. I would just say that, this is really just
taking advantage of the beetle's preference for things that are early, robust, and attractive.
So, personally, as an entomologist trying to get research plots done, I've turned it
upside-down. You know, in a research farm, where I see horticulture people doing experiments
with all kinds of cucurbits, I try and find out when they're planting and I make sure
to get my plantings out two weeks early because I want the beetles. So, you know, this can
work at a farm-scape level. Basically, you're trying to pull the beetles into areas first,
and if you do it in a nice structured thing like Mark was talking about, you can really
use it as a control mechanism. But you can also just pay attention to this across your
farm-scape and deal with where the beetles are showing up first to try to get the first
generation and that'll help as well. We think this might be a fairly potent weapon,
the perimeter trap cropping, but we're still deciding how to aim it properly. I guess,
the other thing I would mention--this is Celeste--that, as Mark briefly mentioned, you definitely
have to pay attention to some other pests. The first year we did it we just got wiped
out by squash vine borer. And it was to the point where we almost had no trap crop by
mid-summer. So the second year we really really were very aggressive about treating squash
vine borer, and it made a really big difference. So that's, well depending on your location,
but we tend to have very high pressure from that pest, so it's really something you need
to stay on top of. It's something that's gotten really bad in Iowa too increasingly in recent
years. Other comments? Okay. Robert Beck has asked if there will
be a listing of other pests to watch out for with various trap crops, something like a
field guide. You just gave us a good idea, Robert. It could
be that we should just add that. When this goes online, when this webinar goes online,
we can add a slide about pests to watch out for in perimeter trap cropping. I think that
should work. Okay. So I don't see any more questions coming
in. We've got about a minute and a half left. I think if it's alright we'll go ahead and
wrap up the webinar. Thanks everyone for joining, we'll be sending you all emails in the future
for some other webinars that we'll be hosting, and have a good night! Any other comments
from our presenters or anyone? Thanks, Hayley, for being our technical genius.
Yeah. Thank you.
You bet.