Vineyard Floor and Weed Management: Expert Forum Discussion

- All right, we will get started.

So I'd like to welcome you to the fifth edition of the Eastern Viticulture and Enology Forum.

We started this back in November, December, 2020, way back when, in the post COVID months, and it seems like a good way to reach people over the winter months in between state meetings and conferences.

So thanks for joining.

I did want to call out that while Penn State is hosting this, this is a collaborative effort between several land-grant universities and their viticulture and enology program.

So I'd like to thank all of my colleagues for joining in on this because the word gets out better, we have more knowledge shared, and I'm just grateful for the collaboration.

So this series is possible because of the collaboration amongst all of my colleagues.

Thanks, thanks to everybody.

Okay, so this is the schedule.

I will share a link during the webinar in the chat that will give a document that shows all of the upcoming webinars in our series.

So we've already had one, viticulture one, back on January 21st, and then our enology colleagues had one of these on January 28th.

And then today, we're doing this viticulture one.

And then next week, next Tuesday, another enology one will show up.

And so I will post this link in the chat.

The next viticulture one that comes up is our disease management one.

So we'll have some panelists that are disease management experts on March 11th.

Okay, today we're talking about vineyard floor and weed management.

And so we have some experts and panelists that have experience in cover crops and vineyards and just cover crops in general.

So that's what we'll be talking about today.

And the way we've designed, at least this year, is for the viticulture portion of these webinars is that we're taking the approach where it's a true form, it's an open discussion where we've taken pre-submitted questions that some of you have submitted, and we're grateful for that.

And we'll answer those and talk about them and then move on to the next question.

And as experts, we've planted some questions that we'd like to answer that we think are important to know about, and then we'll try to take some questions that come in.

All of us as panelists will be monitoring the chat to see any comments or questions that come up, and we'll see if we can get to those too.

Okay, so I'd like to ask, these are...

I'm actually gonna start with somebody who's not even pictured here because, apologies, Madeline, I forgot to include you, but let's start with you, Madeline, and then we'll just go from left to right and you all can introduce yourselves as lead panelists today.

- Sure, thanks, Cain.

I'm Madeline Wimmer.

I am a fruit production educator for the University of Minnesota Extension.

I've been in this role for about a year and a half.

And for those who are familiar with Annie Klodd, she was in this position before me.

Saying hello, it's negative 15 Fahrenheit here today, but I'll mainly be presenting a little bit towards the end about an infographic that I created, looking at herbicide classifications for vineyards today.

So wonderful to be here with all of you.

Thanks for joining.

- Thanks, Madeline.

- Hey, my name's Joseph Amsili.

I'm an Extension associate with our New York Soil Health Program here in New York, more expertise in cover crops and the relation to different soil benefits that we might be seeking from our cover crops and decision support tools and things like that.

- Thanks, Jo. - Hi, everybody.

I am Drew Harner.

I'm a viticulture specialist at Virginia Tech.

I started about a year ago, so sort of new.

And I will be starting a couple of cover crop experiments this year.

So I've learned a lot from all the other panelists here and looking to get into some Virginia-based research.

- Thanks, Drew.

- Hi, my name's Wayne Mitchem.

I'm an Extension associate with North Carolina State University.

I also have a regional appointment where I work across state lines with Clemson and University of Georgia folks to do weed management in tree, fruit, and vineyards.

You know, I do applied work with herbicides and timing herbicides and screening products and tank mixes and that sort of thing.

- Thanks, Wayne.

- Hi everyone, I'm Jennifer Phillips Russo.

I'm the Cornell Viticulture Extension Specialist for the Lake Erie Region.

And I've had a flora management project going on for the past couple of years that's on heavy clay soil and on gravel soil, looking at single species cover crop, multi-species cover crop, and then native vegetation or weeds and three different ways of terminating them to see their effects on the vine and soil health.

- Thanks, Jen.

- Morning, everyone, or afternoon, whatever it is.

I'm Hans Walter-Peterson.

I'm the Finger Lakes viticulture specialist for Cornell, and I'm bringing a little bit of experience with under-vine cover crops.

Done a couple of projects with our colleague, Justine Vanden Heuvel, professor of viticulture here at Cornell, looking at using cover crops under the vines as opposed to inter row.

- Thanks, Hans.

- And bringing up the rear, I'm Alice Wise.

I'm the Grape Extension Specialist on Long Island.

I'm definitely not an expert in this area, but I'm happy to share my experiences and those of growers on Long Island.

- Thanks, Alice.

I think you're too modest.

I think most of us would consider you an expert on this, but we're grateful for you and everyone else.

So thanks for being here, everyone and serving as lead panelists.

So we will get right into it after I just set the stage with some logistics.

We're recording this webinar.

If you registered for it, it will be sent out to you in an email.

We will also have it posted online within a couple weeks, probably.

Use the chat and Q&A tools to engage with panelists or other people.

You can chat with everyone or just us host and panelists.

We will try to get to some questions after we get through the questions that we have either planted or have pre-submitted.

I will submit or put a survey in the chat towards the end of the webinar and I'd be grateful for any feedback you can provide to let us know how we're doing and how we can be better, okay?

So with that, the format of this will be that I will vocalize a question to one of our panelists and that person will answer it.

And if other panelists have something to say to add context or follow up or refinement to that answer, great.

And what I'll do is after vocalizing the question, I'll also type it or copy and paste it in the chat.

So let's start with the pre-submitted questions to this webinar.

Okay, so the first pre-submitted question, Alice, this one, we'll ask you to start this one off.

I have read that bees or yellow jackets do not like the scent of lavender.

I'm wondering if growing lavender in the rows or between the rows would be beneficial as a weed control in addition to being a possible deterrent to bees.

- Well, as a matter of fact, I did grow lavender under-vines only one year.

It came as a recommendation from a consultant who was also trying to get everybody to use compost tea foliar sprays.

So it was presented as something that we could use to enhance the fungal dominance of our soils.

I'm not sure exactly what that meant.

Anyway, it was expensive.

You know, we planted a lot of it.

It did control weeds.

It was quite a dense planting, but it also competed with vines.

And these vines were VSP trained.

So it reduced airflow through the vineyard.

The vineyard proceeded to get quite a lot of downy mildew.

I would say, I don't know about their repellents effect on bees, but I don't think it's personally practical to grow them in the row middle, or under-vines, you know, too expensive, and maybe there are better options.

- Thanks, Alice, does anybody else have anything else to add?

- I have a question maybe for Alice about that, because I had been talking, I think, about lavender with Suzanne Fleishman from Penn State, I think, and one thing I was concerned about was if you have lavender or anything that's aromatic underneath the vine, when you're going through and harvesting with lugs, I was curious about the potential of getting, you know, leaves or anything, whether its lavender or mint or something else into the lugs, and then potentially into the crush pad.

I know that it's a problem with eucalyptus leaves and places that have eucalyptus.

Alice, did you have any experiences with that?

Like were you careful with picking around that or did you find that it wasn't a problem?

- Well, yeah, this fruit didn't make it to any crush pad, but I agree that might be a legitimate concern.

And I know that Anna Katharine Mansfield and Gavin Sacks up at Cornell have done a little work looking at the effect of aromatics.

I mean, like, you know, hemp and cannabis, for example.

If they're growing nearby, they're pretty aromatic.

And I see lavender...

Yes, lavender does attract bees.

Our soils were sandy.

It grew well, we had a lot of beautiful lavender plants, but I would be reluctant to do it on that basis also, Drew.

- And I guess, I'm wondering too, if we're really talking about the connection of lavender attracting bees, but we're more concerned about certain species of wasps that the volatiles might be a little bit different too.

But I know that there is some research that's been done at least looking at tarnish plant bug and using linalool, which is a compound in lavender for trap cropping.

So I'm curious to know, I don't know, but maybe there would be some research out there talking about that.

Alice, did you look into...

That wasn't really the purpose for your experiment?

Yeah, if something, it's like...

- Yeah, I think it's a good point to distinguish between pollinators, which would potentially be all over lavender and yellow jackets, which I think the question was specifically, which can be a pest of grapes especially in the fall.

Anybody who's picked in the fall knows not too hard to get stung some years.

So yeah, so the yellow jackets are not as interested in the lavenders as a pollen source for sure.

But just the timing of when they might be an issue might be a bit off as well for the kind of when they're flowering and stuff.

So like something I would probably experiment with a tiny bit before doing it, but I would follow Alice's advice I think too.

- Yeah, Alice, did you want to give that observation too about the lack of airflow due to like lavender, but probably any high growing cover crop?

- Yeah, well, my fruiting wire, this was in the research vineyard, the fruiting wire is about 30 inches high and you know, the lavender was definitely reducing airflow in the vineyard.

And you know, we were...

These vines were getting a lot of compost tea and a few fungicides, but we definitely had an outrageous amount of downy mildew, and I'm certain it had to do with a lack of airflow in the vineyard.

- All right, well, good.

Thank you, Alice, and thank you to everyone to add some context and the discussion on that question.

We will move on to the next question and that is, is it reasonable to maintain the area under the canopy, so underneath the vine, using a wood chip mulch most of the year and then pulling it back as veraison approaches.

And the added context was that I grow Chambourcin in southeastern Pennsylvania and grape maturation is not a problem.

Hans, do you wanna take a stab?

- Yeah.

I know we've had growers here who have tried different kinds of mulches, hay, more so than anything else, or straw that gets chipped or chopped and blown under the row, but people have done kind of the mow and blow option where you're mowing the vine and the grasses and weeds get blown onto the surface.

People have used wood chips in other places, and the most common thing I hear about those is not so much about water retention or soil improvements or anything like that.

It's "I didn't realize how many rodents I had in my vineyard." It's a great place for rodents to get access to, more so in the wintertime because they will actually chew on the vines, but even so that they can run around and potentially chew on vines occasionally.

And yeah, because it's a safe place, the predators can't find them.

And so that was the experience that I'd heard from several growers who tried different forms of mulch is just that it's a great place for the rodents to hang out and potentially cause some chewing issues on trunks and whatnot.

So that's anecdotal, but I've heard it enough to think that there's something to it.

- Careful with organic mulches under-vines because as they break down, don't they consume nitrogen?

See, that's tricky, my other concern here would be when we get five inches of rain and then we have a nice thick mulch on top of vines, or under-vines, I would be concerned about it stimulating growth too much.

- The one kind of thought I have about just the carbon to nitrogen ratio is that if a mulch was incorporated somehow, that would be more concerning to tying up nitrogen than just having that surface contact where there's going to be more limited microbial activity.

That's just something that's kind of come up in my sphere when talking about mulch recently.

- Maria, did you have something to say?

- I sure did.

So our program actually did a multi-year mulching study in the past five years.

And wood chips in particular were excluded because of the high C to N ratio.

That's why the recommendation is typically for a lower carbon mulch like wheat straw or something else.

And we did see that be a huge problem, especially in Chambourcin, which is already prone to a lot of nitrogen and potassium deficiencies, at least here for us.

And so using wood chips would exacerbate that problem.

We also found just from a logistics standpoint, having to remove that mulch from, depends on how big the planting area is too, is oftentimes unfeasible.

And if those vines are grafted, then it's even more problematic.

But we don't use it necessarily for weed suppression, although it did do a very good job in that.

We used it mostly for graft union protection as an alternative to soil hilling in vinifera.

So that was the other consideration for us when we were looking at mulch.

But yeah, I mean, it can be, it can be feasible.

We have a couple of sites that have adopted mulch as a practice for weed suppression and winter injury graft union protection, but it is a lower carbon range.

- Thanks for sharing that Maria.

And just a couple things that have come up in the chat is, you know, voles really like under-vine hills and weeds, cutworms love mulch.

Which is worse, the C to N ratio, sappy nitrogen, or having weeds under the vines competing for nitrogen?

You know, we could only speculate about that.

All fair practical concerns and points.

All right, well, let's move on to the next question.

Thank you all for entertaining that one.

Jen, if you wanna start this one off, that'd be great.

The question is, I'm interested to know if there's any data on planting native seed in the inter row, so inter row being that area between vines, not underneath vines, versus fescue and the potential effects on vine health.

So if Jen, you want to kick things off and anybody else that wants to add, please do.

- Absolutely.

So in our experiment, we have a single cover crop species, something that we have planted, either a cereal rye or a cereal oat, depending on the year when we flip 'em back and forth.

We have a multi-species cover crop anywhere between five to seven different species that we add.

And then what we have is what we call the native and that's whatever wants to grow in the middle row, which is basically usually a weed species and whatnot.

And we have been studying the effects on infiltration and compaction and also soil health parameters around that and weed suppression.

And I have to state that at least my research has been showing that the cover crop species do a much better job at suppressing weeds and compaction and infiltration than the what we call native seed species or anything that's going to populate itself there.

I'm not sure if that quite gets to the answer that you're looking for, but for the most part, those weed species have really shallow rooting systems and they just don't break down and they're really good at competing and taking up that space where the other beneficial cover crops that we're using to either have the water infiltration or mine some nutrients and then lay and finesse those nutrients back to the vine as they die.

Is that helpful?

- I think so, yeah.

For sure, and I think these questions too, you know, the question was, is there any data, and it's like, well, what are you...

I guess one question that I have for everyone who's asking about cover crops are what are you looking to...

How are you looking for them to benefit you?

Are you looking for decreased vine vigor?

Are you looking for reducing compaction, rutting in your vineyard, adding water infiltration?

Like these are all things that will help guide you to maybe making some cover crop choice decisions, is what are your vineyard management goals and how do you want them to help you, you know?

And so in this case, Jen, I think it's a really good point about the structure of some of these non-native cover crops that can add...

Well, it helps reduce...

It helps preserve soil properties, you know?

- Exactly, all on what your goals are, I agree.

- Anybody else wanna comment on that one, on the native seed versus something else that's not native that's intentionally planted?

- I think it can really depend on your seed bank and then also people could put species that are native out there, so it could really depend on that front. - Yeah.

- Yeah, as somebody who works with a forester who focuses on invasive species, I'm always putting out that public service message of be mindful of where you source anything that's native because there is a high probability that that there could be invasives that it hasn't been kind of looked at and or analyzed before being sent out.

So know where you're purchasing native seed from.

- Yeah, thank you, Jo.

Thank you, Madeline.

All right, well, we will move on to the next question, and I'll actually ask Alice to start this one off because I think it's something that Alice has some experience with there, both at her research farm, but maybe in the industry there on Long Island.

The question is, what are your thoughts on mechanical weed removal for under-vine management, such as a Clemens or finger rollers or finger hose?

Do these tools help in any way with nutrient absorption when fertilizer is applied?

How do you feel about cover crops to help with weed control and putting nutrients back into the soil, and that's specifically clover?

So there was a few questions there.

Alice, why don't you start off by talking about the mechanical management. - Uh-hmm.

- Maybe Hans can comment on the clover one.

- Yeah, other people can jump in if they want.

So we're in a bit of a unique situation on Long Island in that we're one of the most environmentally sensitive areas in the country.

We don't have a lot of products that are labeled, including herbicides, that are labeled elsewhere in the country.

And in addition, there's a real strong interest in trying to reduce pesticide use.

So we went from pre-emerge and post-emergent and being real common to post-emerge, only being real common, I'm talking under-vines.

To a lot of people, mowing, had under-vine mowers, that offered too much competition plus the mowers broke a lot.

You had to be real careful, you know, drive very, very slowly.

But now, I'd say the thing that's gaining popularity here is cultivating under-vines, and there's a variety of implements.

There's some of those...

I don't know the technical terms, there's those under of the soil slicers where it just slices up underneath the vines kind of and sets it back down almost.

There's the finger, the rotating finger weeder and then there's the star wheel.

And so all of those are used to varying degrees, some in combination with organic herbicides.

One grower tells me that he uses organic herbicide just to kind of buy him some time, buy him a couple weeks when he gets behind.

Yes, I'm talking about the Braun hoe.

So, you know, I'd say that's the most common thing now.

Do they help with fertilizer incorporation?

We don't use a lot of nitrogen here, so I'll punt that to somebody else.

- Thanks, Alice.

That's good feedback on the mechanization.

Hans, did you wanna talk about the clover aspect of the question, which was, how do you feel about cover crops to help with weed control and putting nutrients back into the soil, specifically clover?

- Yeah, I think, I mean, it's one of the...

It's one of the things that cover crops are really good at, obviously, is taking up nutrients and then kind of recycling them back into the soil in more plant available forms or, you know, or just bringing stuff up from depth and bringing it up higher if you have a shallow-rooted crop.

So one of the experiments that Justine did in one of our research farms several years ago is looking at several different cover crops under the vines and actually had lysimeters, which are basically liquid collection buckets that you bury in the ground and collect the leachate that comes through.

And so she had lysimeters for several of these different cover crop treatments and clover was one of them, white clover.

And the interesting thing was that there were two, there were two flushes of nitrate released into the lysimeters in the spring and then later in the summer.

And so like significantly more than the other cover crops.

And so what that means basically is that the clover is fixing so much nitrogen and releasing it into the soil, it's more than the vines need.

And so you're actually getting leachate with heavier amounts of nitrogen going into the groundwater, leaching outta the root zone.

And so for that reason alone, well, here in the Finger Lakes, we're on lakes, a lot of our groundwater moves towards our lakes, and that's obviously what we don't want.

So we've really gone away from recommending clover in, definitely under the rows.

And I even, kind of, am not sure that it makes much sense in between the rows other than if you're using it to help, if you have a low nitrogen site and you need that help.

But I mean, when you think about the timing of nitrogen demand, if there's a surge in the spring when the things are first starting to come wake up, the vines aren't using any nitrogen, they're all using, they're using reserves.

So there's really no uptake from the vines at all.

And so all that is just either going into the other weeds that are active or it's getting flushed out of the soil.

So I understand the argument for it and I think it makes sense in some systems, but I think in a lot of our vineyard systems, it's not the best idea.

- Meaning the use of clover.

- Yes, yeah, specifically clover.

- Anybody else have anything to add on the mechanical weed management and/or the clover and the nutrient unloading that Alice and Hans have shared?

- Hans you mentioned that, you know, if you have a low nitrogen vineyard site, that that might be helpful.

Can you talk about organic matter levels in the soil and how that might influence the nitrogen leaching from white clover?

- Yeah, I mean, to the extent, I mean, organic matter is a nitrogen source, right?

So when the microbial community in there breaks it down, one of the things that releases is nitrogen.

So if you have higher organic matter in your soils, you already have a pretty good supply of nitrogen that's being generated every year as long as it's not, you know, fixed in some way, obviously.

But if you have a low...

I mean, kind of, the other side, the other side of that coin then is if you have a low organic matter site, which probably means you have more sand than loam and clay, that's also a higher leachable soil, right?

So you're almost kind of have this double-edged thing of...

The system that you want to put it in probably may not be able to hold it in place.

I mean some place, like some of the soils that Alice's farms are on on Long Island, you know, nitrogen leaching is a very big deal because there's very, very sandy soils.

So putting clover on there, even if it's an amount that the vines could use, might still be too much.

And again, the timing thing is a bigger deal too.

And so you might not be getting the benefit of the nitrogen that you think you are is basically kind of what I'm saying.

- Thing to add as well is nitrogen fixation is extremely energetically expensive for legumes to do, so if there's already nitrogen available in the system, they're not gonna fix their own nitrogen.

They're just gonna scavenge nitrogen.

So that's, yeah, one other thing to think about.

- Yeah, good point.

Well, good.

Thanks for the feedback on that and that's good discussion.

And I also wanna comment, there's lots of great comments and observations coming up in the chat.

I'm trying to read them while also manage the webinar here, but I'm really grateful for all the feedback and the comments because, especially when everyone can see 'em, it adds another level of context to what we're discussing here.

So thank you for all that.

This one here is about using a torch, a propane torch for early weed control.

So it says our vineyard is established and we've been utilizing both contact and pre-emergent herbicides.

Control has for the most part been good.

However, in one of our vineyard sites, we have weeds from the Palmer family, red pigweed and amaranth, therefore we are looking at utilizing a propane torch for early weed control.

So basically, they say we've used it on a smaller scale, are there any dangers of using this propane torch against the trunk?

And so I can't remember, Wayne, if we're gonna direct...

I know the next one's directed towards you, but Wayne, have you had any experience about using a propane torch for weed control?

- Oh, I've not done any experience myself with it, but I do know that with using the propane torches, you know, you're talking about an open flame, so you have to think about driving fast enough to not damage the bark of the vines.

But at the same point in time, those weeds do need to be small so they can, you know, be torched and the heat take care of them.

So, but yes, you do have the potential to damage the trunks if you drive too slowly or move too slowly past those.

You know, the other thing that I have concerns about with torching is, you know, if you've got, if you've got vegetation in those row middle and during dry periods and dry weather, it is a open flame.

And so there is concern about potential fire risk with that.

And you know, one of the things that happened years ago, I think Mississippi State, somebody was doing some flaming work and research and actually burn up a tractor in the process of doing the experimental use.

So, you know, it is fire.

And so there are risks with that.

As far as dealing with Palmer amaranth, you know, chemically, there are some products that we can do that with.

So you want me to go into that Cain or...

- Ah, let's see here, before we do, does anybody have anything, other context to add to Wayne's comments on using the torch other than the inherent danger, potential issues with damage to the trunk and needing to...

And I think there's a lot of these weed management approaches, whether it be torch, chemicals.

I mean, hitting these before they get of size, and I don't know what of size means, is really important, right?

Otherwise your management is just not gonna be as effective.

- Yeah, I think for flaming, you're talking about, you know, two, three inch tall weeds max.

- Yeah.

- I've seen wooden line posts scorched with them too.

- So proceed with caution if you're gonna do that.

Okay.

Let's see here, Wayne, I think the next one, here we go, we'll go into this one.

Looking for products that are pre or post-emergent labeled for grapes that do a better job controlling Palmer amaranth, morning glory, horse nettles, sedge grass.

Under row cover cropping of creeping red fescue, while dense, did not suppress these persistent weeds so I'm back to trying to manage them with herbicides.

And so Wayne, this might be a good time for you to talk about maybe what chemistries are good on some of these more noxious weeds.

And then in a little bit, we'll go on to the programs that you have for pre-emergence.

- Okay.

You know, for Palmer amaranth and the, you know, pigweed species, the biggest thing with Palmer amaranth...

Of course, we have a lot of glyphosate-resistant Palmer amaranth due to the fact that that's a common weed in row crop situations.

So assuming that most of your Palmer amaranth is glyphosate-resistant, we're gonna have to be thinking about other options for managing that weed.

From a post-emergence standpoint, you know, glufosinate is a logical one to move to post-emergence that will take care of Palmer amaranth.

Aim has some post-emergence activity as well, but the key with the Aim is they have to be, you know, one, two inches tall.

With the glufosinate, you know, three, four inch tall Palmer amaranth can be controlled post-emergence.

You would need to put it out with a spray grade ammonium sulfate fertilizer in that tank mix to give you some added burn down.

And the other thing with glufosinate is they found that particularly with Palmer amaranth, you know, time of application during the day can make a difference.

You know, if you're applying late in the afternoon, closer to dark, they had less desirable results than if they put that product out at the same rate in the middle of the day in direct sunlight.

So just a factor you might want to think about if you're applying those products, they work better in the heat of the day.

Paraquat, you know, it is got its issues from the standpoint of a handle issue and a toxicity issue and there's additional licensing requirements to use that product, but it's still good post-emergence on pigweed species that are a couple inches tall.

Pre-emergence wise, Chateau or a generic flumioxazin product is good pre-emergence control of pigweed and Palmer amaranth.

The Zeus product would also give you some good residual control with Palmer amaranth.

Rimsulfuron, which would be Matrix, proven that would have some activity.

The pendimethalin products, the Satellite HydroCap is a generic alternative to Prowl H2O, would give you some pre-emergence control with Palmer as well.

I believe the other weeds you mentioned were morning glory was one, next, I believe...

- Yeah, so there was morning glory, horse nettle, and sedge grass.

At least that's what they mentioned here. - Okay.

- If you have anything on bittersweet or nutsedge as well.

- Okay, with the morning glories, you know, the Chateau products or the flumioxazin products are really good, but the key there is you have to bump those brakes a little bit.

You know, if we get below eight ounces of Chateau, we're not gonna get as much residual control, especially of morning glories, as we will with, you know, 10, 12 ounces of Chateau.

So eight ounces is kind of a breaking point there for Chateau with morning glory, in my opinion.

You have to be at least at eight ounces or increase that up to 10 or 12 ounces.

You would have some activity on morning glory as well with the Zeus.

It would give you some activity.

Simazine is not gonna be a great morning glory product.

So again, I go back to the flumioxazin, it's probably gonna be your best choice there, followed by the Zeus Prime.

For horse nettle...

Oh, well, post-emergence on morning glories, glufosinate, paraquat, and Aim actually is pretty good on it, and Aim is a little more forgiving with morning glories than it is in some of the other weeds.

You can get morning glories post-emergence with Aim that are, you know, three, four inches tall.

With the horse nettle is a very challenging one because we just don't have it.

It's a perennial, it's coming back from the rhizome, don't have a whole lot of options there.

It does a real good job with that.

Pre-emergence, you can pretty well forget.

You're not gonna get a whole lot out of it.

Glufosinate will give you some knockdown of it.

You know, you probably looking at having to use 48 fluid ounces as a minimum with the ammonium sulfate.

You know, if it's where you can spot treat it, glufosinate is pretty, not, excuse me.

Glyphosate is pretty effective on it as a spot spray.

It would need to be times when the horse nettle has flower buds forming, about a 1.5% solution would be the amount of material you'd need to use for a spot spray.

So the horse nettle one is the most difficult.

And again, I don't think it's that...

It's not as competitive as a lot of other weeds, but it's more of a nuisance and a eyesore really.

The nutsedge, no question, the best pre-emergence option for nutsedge is gonna be Zeus or Zeus Prime.

Anything with sulfentrazone in it is excellent for nutsedge, especially yellow, does a really good job, and it's gonna give you residual control.

And, you know, a couple years of running that Zeus back to back, you can clean up some nutsedge problems to do a pretty good job.

Rimsulfuron will give you some suppression, so that would be something you could even consider in tank mixing with something like a glyphosate if you're putting it out post-emergence, or glufosinate to give you some suppression post-emergence.

But no question with nutsedge, the key, in vineyards are gonna be to use Zeus and approach it from a residual standpoint, which is a little bit backwards to what we typically think of with perennial weeds.

The other one was bittersweet.

And the bittersweet is, the one I'm thinking about is a perennial vine.

You know, for the most part with perennial vines, we don't have a lot of options because of a lot of the weeds that take care of vines and perennial vines are also very hard on grapes.

And we go to look at what our labeled options are, we're back to basically spot treating with glyphosate, probably gonna be a late summer or fall application.

Probably 1.5 to 2% solution was probably gonna be your best option on that.

And that's really gonna be the only option you really have to try to manage that one.

- Wayne, thanks for all the feedback about chemistries and their effectiveness on some of these weeds.

(phone vibrating)

- I see one questionnaire in the chat about the adjuvants. - Yeah.

- And I wouldn't say with glyphosate, you know, they're typically pretty well loaded.

Most of our generic glyphosate products and you know, our Roundup PowerMAX have glyphosate.

They already have adjuvants in them, but if you wanted to add a little bit of a nonionic surfactant to that, that would be fine.

The spray grade ammonium sulfates, the water soluble fertilizers work really good with glyphosate and the Rely or the glufosinate with the Rely products.

It's already loaded with surfactant, so I wouldn't put any additional surfactant in that, but I would use the ammonium sulfate.

With paraquat and Aim, definitely you would wanna use crop oil with Aim, with paraquat a non-ionic surfactant.

- All right, thank you, Wayne.

We have another question or two for you about timing of programs for pre-emergence and also a question about 2,4-D and dicamba chemistries, but we'll come back to you in a bit.

- Okay.

- You took a while or, I shouldn't say, took a while.

We are grateful that you took so much time to answer those.

We'll give you a break.

You've earned your break. (laughs)

All right, so moving from chemical management and going back to kind of more into cover crops.

Let's see here.

I actually have a couple that Jo suggested we address.

And so Jo, I'll send this one to you first.

You know, there are so many cover crop species and cultivars.

How do we choose the ones that are best for our intended goals?

- Can I share a couple slides to help?

- Sure.

Let me allow you to do that.

All right, you should be able to now.

- Okay.

Well, yeah, this is a great question.

There are a lot of different cover crop species and now cultivars, if you go to different cover crop seed catalogs, there's a lot of...

We're putting the emphasis on cover crop breeding like we did do for our cash crop.

So there's a lot of options out there, and it really comes down to thinking about what your primary goals are for cover crops.

So cover crops are multifunctional tools.

They'll have all of these benefits.

Some species or mixtures will be able to supply some of these benefits, greater than others in terms of fixing nitrogen, suppressing weeds, suppressing pests and diseases, increasing infiltration, reducing erosion, helping to decrease soil compaction, providing floral resources for beneficials, decreasing leaching of nutrients, and erosion.

And all of them, of course, add organic matter.

So I think this is a big question that we get a lot of, how do we choose which cover crops are best for different goals?

It can seem overwhelming and I think it's always important to note, at least from a soil health perspective, that having a cover crop is better than no cover crop.

So this is an iterative journey to fine tune what works for your system and on your farm.

So yeah, there are a lot of different options out there, and I think it comes out of this, which is we're used to thinking of ag inputs of having one purpose, but cover crops really require this kind of adaptive management approach where certain cover crops are gonna be only economically effective if they're planted at the right time.

So we need to be thinking adaptively in terms of that.

And there are some really great tools that have been developed.

So this is the cover crop selector tool from the Northeast Cover Crop Council where you can basically put in your location and your top priority.

So here's three goals that were put in here, and it basically ranks those cover crop options depending on when you're gonna seed that and when they'll be effective to.

So this is a great tool, it's really important to know your kind of cover crop, agronomy, kind of what are the cheap cover crops, what are the mid-tier cover crops, more expensive cover crops, and kind of have a handle on some of this basic information.

But yeah, I'll start there with that answer to the question. - Yeah, that's great.

Jo, is there a link to this you could share in the chat?

- Yes, I'll share this with you.

It's being put up momentarily so it's not currently on our website.

So this is kind of geared for upstate New York.

Sorry, Alice, that's a contentious term maybe, but some of this seed cost stuff, I think, is good generalizations of kind of...

We looked at a bunch of different seed prices from across sources from across New York state and kind of averaged what that scale was.

So yeah, I'll give this handout to you.

- Okay.

Great.

That seems like a great tool.

Let's see here.

So Jo, we'll go with another one of your pre-planted or planted questions.

You know, I'm interested in cover crop mixtures.

How do I go about designing seeding rates?

- Yeah, that's a good question and I'll back up here.

I think there's a lot of hype about mixtures and mixtures do great things, but if your goal is...

If you have a specific or unique goal, it's possible that just a monoculture is gonna be best for that specific goal.

But if you want to hit a broad suite of these services, then that's where mixtures can come in.

There is a nice mixture tool.

This was developed in New York that lets you play with some of this stuff.

A lot of these seeding rates for mixtures are really sensitive because depending on how much seeds you put out there, you can really have a mixture where one species really dominates.

A common example is the brassicas that if the conditions are right, you mixture of five species or whatever will just be brassica.

And there's a lot of great companies, King's AgriSeeds and others, that have already dialed in some of these mixtures.

So you're getting something that is more likely to work, but it's also not rocket science in terms of designing mixtures if you wanna play with it yourself because it's fun.

So some of these kind of general principles that this tool kind of shows, and it really does depend on your goals, but sometimes people recommend, like if you're combining a grass and a legume, maybe you're gonna use the full legume rate, but maybe you're gonna use half of the non-legume rate because non-legumes will be a little bit more competitive for nitrogen and water than potentially the legumes.

The brassicas, we always come to this point, especially in agronomy, super sensitive to seeding rate, especially if there's a lot of nitrogen availability.

So you really wanna cut that monoculture rate extremely, like maybe one or two pounds of those species per acre.

And then there's kind of the similarity factor.

So if you had crimson clover and another legume, you'd maybe dial both of those monoculture rates in half because both of those legumes are providing similar functions.

But there's a lot of farm-tuning or fine-tuning that can happen on this.

Sometimes half a rate for the grass monoculture might not be enough because things like cereal rye are really competitive.

So you might have to play with that and really dial it back to try to get the mix of the species.

And one thing that's also complicated is when you have a grass and a legume.

The expression will kind of self-regulate.

If there's a lot of nitrogen fertility in the soil, the grasses are gonna have a better competitive advantage.

Whereas if it's low in fertility, then the legumes are gonna have more competitive advantage.

So it also really depends on the context, the soil organic matter and how much fertility there is.

- Great, thank you, thanks, Jo.

Does anybody else have anything to add to that about seeding rates or cover crop mixtures?

- I would just say, be careful with your daikon radish.

Do not overload that or you will break your ankle walking through the vineyard.

- Yeah.

Going back kind of and some of my viticulture colleagues on this panel might want to add, but before we miss the boat on just talking about like viticulture 101 and how it relates to cover crops, some things that I've learned about cover crops, and please, again, add to this, new vineyards is not a good place to use under trellis cover crops, right?

They're young, their roots are shallow.

So I would say, yeah, maybe after years, three or four.

And again, sometimes folks are planting on steep slopes and you want to keep soil in place.

So you might want to narrow your herbicide strip in situations like that, but young vines really do not like competition at all, including from cover crops.

So that's the one viticulture 101 thing about cover crops.

The other is that while cover crops can provide benefits and help us reach goals, like Jo just said, there are some drawbacks.

They can harbor arthropod pests, some which we don't want in our vineyards.

They can compete for nutrients that we want to get to our vines.

And I know sometimes the goals with cover crops is to reduce vigor and that's fine, but we also need the plant to be metabolically healthy and have ample nitrogen for fruit set and things like that.

So I'll stop there and just stop the viticulture 101 in light of cover crops and ask if my colleagues have anything else to add.

- I think the thing to always keep in mind is that plants, just like anything else in nature, are in competition with one another for the pool of water and nutrients that they all need to survive.

So when they're young, grapevines, I mean, when we've all put a grapevine into the ground, there's tens of roots if you're lucky, when you're planting, as opposed to if you pick up, you know, any kind of bit of sod, there's hundreds of roots in there.

And if they're all in the same plane, you know, all, well, the same depth of soil, those grass roots are way more competitive than those few grapevine roots are there.

I think Cain's point, this kind of just goes to what Cain was talking about with young versus older vines.

Once those vines are able to get further down into the soil profile where a lot more of the cover crop roots aren't located, now they have more free access to things.

There may be other things that are causing problems like hard pans or high water level tables or whatever, but the roots are in competition just like we are above ground.

I always remember something that one of our colleagues said a number of years ago that it's much easier for vines...

There's much more vine competition when vines are young below ground than there is above ground.

And so just remembering that we can increase competition as the vines get more mature and as the roots are not in that competitive environment with the rest of the cover crops.

- Yeah.

- One thing too, Cain, I think you have to acknowledge that, you know, the competitiveness of the plants vary from species to species in cover crop.

Just like with weeds, you know, we know the Bermuda grass is much more competitive than something like, for example, the horse nettle would be.

So I think you have to think about...

If you think about a cover crop, you have to think about the competitiveness of the cover crop you're using.

- For sure.

And I think that tool that Jo showed us might help with that.

Good point, Wayne.

- I have a question for Hans.

What do growers that are on slopes in the Finger Lakes do for weed under-vine management?

Oops, looks like Hans slipped out to go to the restroom or something.

- Does anybody want to comment on that, Drew, Maria, about what are trends in cover cropping in vineyards in your state?

- Yeah, we definitely don't really have that much widespread adoption of it.

So it's something that we're interested at looking more in, especially as it relates to some of the responses of cold hardy hybrids to different types of, not necessarily species of cover crops per se, but at least within different perennial grasses.

That's been one of our initiatives over the past year or so that we're continuing to look at when it comes to new and different types of turf mixes because we don't actually have a lot of information on that and part because a lot of the historic work has been done on creeping red fescue alone.

But I talked to our turf specialists and they're like, "Why?" And I said, "I don't actually know.

I'm not a grass person, right?" So, yeah, we're looking at the response right now in Marquette to different species of fescues and grasses.

- Hmm.

- And I should say that's under-vine, not in the row middle.

- Thanks, Maria.

Let's see here, Jo, before we move on to chemical, going back to a chemical management of weeds and maybe not using cover crops as management tools to outcompete with weeds or whatever.

Was there anything else that you wanted to say with some of these planted questions before we move on?

I feel like you covered a few different points.

- I think I covered it unless people have specific questions to follow up. - Okay.

- Are you talking about non-chemical ways of weed control using cover crops, 'cause I do have a little bit of data on that if you're interested.

- Yeah, definitely, Jen.

There's a question in here that you pegged for, which is distinguished between inter or under-vine trellis crop and what's the difference and how might it affect vine health?

Is that something you wanted to touch on in this, what you're about to say or no?

- I can touch on that just a little bit.

And again, that goes back to it's, what are your management goals?

So we consider under-vine as something that's gonna help pull vigor down and also used as a soil health component.

We are working on, and the research that I'm doing is to build some vigor and soil and water nutrient conservation.

So we're working specifically in the middle row or inter row, if that's what people are looking for.

And I can tell you that I do have one of my treatments, which is called do nothing, and that's just don't even manage the weeds.

When I say weeds, it is weed species that are that whatever is going to populate in those middle rows without intentionally putting something down versus two different types of single cover crop species, and one is a Dutch clover, because growers had specifically asked me, "I want something that I never have to do anything with.

I just wanna plan it and walk away and what will happen to our vines." So we're looking at that.

The Dutch clover, when we're talking just about weed species and the weed surveys that we're doing within the treatments, the do nothing had 251 different, not species, but numbers, abundance of weeds, and the on-average and the panels and the Dutch clover had five. (laughs)

So there was a huge difference when we were trying to use different treatments for different goals for its weed suppression and bringing some of those nutrients to your vines.

Definitely, we have some recommendations moving forward with that.

And I should say that this was huge 'cause we terminate them three different ways, either mowing, roll crimping, or an herbicide burn down, and we're watching the fluctuations between all different trials for a couple years.

So yeah, so it can be use as a weed suppression without using something to mow anything down or herbicides.

- That's really interesting work.

Thanks for sharing that, Jen, and we look forward to hearing more about it.

Hans slipped away a second and there was someone who wanted...

Alice asked him a question, and Hans, I think, the question was is what, in general, if you have a sloped vineyard in the Finger Lakes are there trends for how folks are approaching cover crop use, you know, between maybe the data that Justine's come out with and some of the other stuff that like people like Tony Wolf or Alice have done?

- Yeah, it's...

I mean, the biggest thing for us has been...

You know, there's still a lot of...

Everybody, you know, still keeps an herbicide strip for the most part under the vines, even on some of these slope vineyards.

But the thing that makes a big difference is maintaining a good healthy cover crop, 'cause most of our vineyards go across the slopes.

They don't go up and down.

And so if you're going across those slopes, if you keep a good healthy cover crop between the rows, whatever surface runoff is going to happen from under the vines gets at least slowed down if not stopped by that cover crop.

And so that's one of the main things we do is that we don't really till very much in between the rows anyway, just because we had so much rainfall.

But that's the biggest thing.

And one of the things that I've been talking to growers about lately is actually whether it's changing boom height or nozzle selection or whatever, but actually just narrowing that spray band underneath the trellis.

We have a few vineyards here where the spray band is actually wider than the inter row cover crop, and it's just kinda like...

It's just such a waste of...

It's bad soil health practice and it's just a waste of herbicide.

And so I'm trying to work with, and I'm not a sprayer expert at all, but I'm trying to talk to some of these growers about just kind of like, again, kind of changing their practice, whether it's changing boom height or nozzle selection or whatever.

Just be like, you can make it an 18-inch band and still have plenty of control around that and not have to worry about that so much erosion.

So on those sloped vineyards, that's kind of the biggest thing.

We have a couple of vineyards that go up and down some of these slopes, and I just think from a soil management prospectus...

You see it in the...

You see it on the soil profiles every year.

You just see this pile of dirt down at the bottom of the hill around the end posts and so- - Yeah, independent on the slope of the site, it gets unsafe to work going across the slope, right?

You know, we see some- - Oh yeah.

- Yeah, so as long as you're not at a really steep, steep slope, I think going across the slope makes sense.

I don't think there's too many really exaggerated slopes in the Finger Lakes that I'm aware of.

They're all kind of gently going down to the lakes, at least as far as I'm aware.

- There's a few of 'em now. - Okay.

- There's one that looks like it's straight out of the Mosul region and- - Okay, okay.

I've seen a lot of gently slope vineyards in the Finger Lakes. - Yeah.

- But yeah, I mean tractor, it's like all this philosophy about erosion and soil health and all that, it's like, well, you want to keep your tractor upright.

And so that's- - Exactly.

- You know, something you said there, Hans, reminded me.

Some of you folks know that I hung out with Tony Wolf for about six years when I was getting my master's and PhD and he always said that a healthy soil is one that you can't see, meaning it's covered, right?

It's covered by some sort of cover crop.

And I thought that was a really good insight, because with him, when it's exposed, as Hans was just talking about with these really big herbicide strips, that soil is now vulnerable to so many things that can decrease its quality and properties.

Yeah, Drew.

- I had a quick question for Jen, not to switch gears, but on the topic of termination for cover crops, because I had a situation here in my own vineyard where we had a perennial fescue and I wanted to basically transition it to a different under-vine cover crop.

And I found it to actually be a much more challenging process than we thought it was going to be, or more just, you know, like, what's the optimal methods?

And then some seed suppliers told me that I can just direct seed right over the cover crop after we terminated the fescue.

And that, you know, most of these, in particular, are legume seeds, that the legumes would sort of just grow through it.

But I had a question, I guess, do you have any comments on that or what are your experiences?

Did you guys seed those panels after terminating too or no?

- Yes, we did. And I'm gonna ask Joseph to actually unmute and help with this one too.

Sorry, I see that you might be chewing, I apologize, simply because he has been the guy that I have guided to or went for guidance to on these questions.

We terminate and then seed right over.

We do even row crimping when we terminate and seed right into that for our next season as well.

But with the fescue, I've heard that there has been a couple issues of trying to get things to actually grab, and that's contact, 'cause they're so dense, that mat that they leave.

So Joseph, did you wanna add anything to that?

- Yeah, I don't have too much to add, most of my experiences with annual species, but I can imagine, yeah, with a big sod, you could have some serious issues.

- All right, what I'd like to do now is switch gears and go back to chemical weed management.

And with that, I'd like to call on Madeline to go ahead and introduce the nice resource you've developed.

- Yeah, and unfortunately, this isn't posted online, so maybe we can just kind of...

I can post in the chat or I don't know if you can post that there, Cain.

- Yeah, if you can get the...

You mean that you can't provide a link?

- Yeah, I don't have a link for it right now, so that's the challenge.

But I'll at least share my screen and I can if the chat allows me to drop something in there.

Yeah, I don't think it does right now, but I don't know if we can email it out to folks perhaps after the meeting, but I'll share my screen here.

So I've been giving talks a little bit on organic weed management.

I'm currently a board member on the Organic Fruit Growers Association and I'm also on the Minnesota Institute for Sustainable Agriculture Board.

So sustainability has been one of my initiatives as well as working with new growers.

And I feel like this handout or this infographic, however you wanna look at it, kind of really does it...

It can be really helpful for folks who are less familiar with chemical classifications.

And this is not going to go into full detail, but this is really a handout that helps you understand how different herbicides relate to each other.

And it's basically was pulled out of the Midwest Fruit Pest Management Guide.

So if you ever look at any of those chemical lists, you kinda look at it and you're like, "Okay, I get what's going on, but, you know?" And there's maybe not a mode of action there.

So I just took all that information and understanding, you know?

When we're talking about weed management with vineyards, you know, not only we're talking about pre-emergence and post-emergence, but age restrictions.

Some herbicides are, you know, there's restricted use pesticides as well, but perhaps, you know, certain chemicals are only allowed for non-bearing years.

And that's why I kind of wanted to come up with this.

So once we can get this handout to you, I'm hopeful that it might help a little bit, just at a glance, not only understanding how the classifications relate to each other, but I also have included some modes of action just to inform folks about what chemicals you might be using and where might you be able to rotate chemicals.

So, oops.

So, at the end of the handout, I do list the modes of action that are included in the herbicides that I'm listing in this handout here.

But yeah, it basically has one full page on pre-emergence classified as herbicides are okay for all vines.

And the way that you can read this is that every bubble basically has a trade name, the active ingredient listed under it, the mode of action or the group number.

And then again, this is loose, right?

So Wayne just broke down how well you can use different herbicides for specific crops.

So again, refer to the label, this is just a generalization, but generally, are they going to be targeting grasses, broad leaves?

Primarily grasses, primarily broad leaves, or both.

So then the backside of the sheet or, sorry.

So then the second half of the first sheet kind of breaks down those vine age restrictions based on how old they should be.

So one year older, two year older, or three years and older.

And then on the back here, I just have post-emergent herbicides as well.

And then there's just a small star note there for a couple that can be used for sucker management.

So this is something that is going to be posted on the University of Minnesota enology and wine, grape website.

Hasn't quite gotten there, but hopefully we can get this to you all at some point.

So that's about all I have to share on that.

- That's great.

That's a great resource.

Thanks for doing that, Madeline.

- Yeah, absolutely.

- And for both Madeleine's resource and also Jo's, I'm not sure.

I'm not the one who's actually emailing these recordings out afterwards.

We have an event management team that does that at Penn State.

We're lucky for that.

So I'm not sure if I can actually send these emails out with these resources.

So what I would say is if you're inclined and interested, email Madeline or Jo and I think they can point you to these resources perhaps better than I can, because I can't promise that I can send these out, although I can ask.

Let's see here.

All right, thanks again, Madeline, that was great.

- [Madeline] Sure.

- Let's see.

I'm gonna jump to a actually kind of an herbicide drift issue because this was a pre-submitted question, and Wayne, I'll direct this to you.

I was recently told that neighboring farmers that use 2,4-D and dicamba in their fields have options using an acid based or salt based form.

I believe they said the acid base was not as volatile and it was also effective.

I don't want to use it on my vineyard, but you know, which is safe, if any, for neighboring farms?

- Yeah, that's being driven by the issue where we've got the 2,4-D and dicamba-tolerant crops.

They have developed a 2,4-D and the dicamba.

The dicamba ones is the Embed Extra or all the...

Du-du-du-du, the other ones goes to my mind, but they are special products supposed to be used over those dicamba-tolerant crops.

They are different from the pasture versions of those products and, you know, the corn versions.

They are less likely to move.

You know, where we have, a lot of movement occurring and where you get a lot of press talking about the movement of dicamba into vineyards.

A lot of that's being...

This movement's occurring because of growers not using the proper, more expensive formulations that should be used over the top of those crops.

The 2,4-D one, the 2,4-D choline, which is Embed, we've actually directed it underneath vines and put it out.

And surprisingly it, it doesn't move.

Now, it'll never get labeled for use in grapes, but the 2,4-D choline does not move at all.

You just don't have any problems with it.

So if your neighbors are using, you know, dicamba 2,4-D tolerant crops, yes, they need to be using the products that are specifically designed for minimum drift and put in the additional drift retardants that are expected to be used by the label over the top of those crops.

- Thanks, Wayne.

Okay.

So Wayne, actually continuing on with chemistry, we had you up here in Pennsylvania to give a talk on programs, pre-emergence programs.

Of course, when I was at University of Georgia, I saw you give this talk a lot.

And so I was wondering if you might be able to just kind of overview, if someone's looking to get ahead of weed control and not wait to only do post emergence but really look to get a good pre-emergence program going, what are some of the timings and or chemistries you could recommend and just breaking it down simply for vineyard options?

- Yeah, and, well, in the...

You know, in the eastern United States, we have a lot of summer weeds, and that's where a lot of our competition comes from.

So we've tried to look at programs that basically push back to pre-emergence applications.

So we've got a couple of programs, one can start in the fall.

Problems where you have with using fall pre's are where you've got slope erosion is a concern.

And I know y'all have talked about that a little bit with cover crops.

But generally, if we put out a fall application of a pre here and we've got geography that's erosion isn't a concern on, we don't have to come back with a second pre until, you know, probably around the 1st of June in western North Carolina.

So that's one option.

Another option would be what I call a late winter summer split where we'd go in mid March in this part of the world with a non-selective burn down and a pre-emergence herbicide.

Generally, that would get us into, you know, probably June, late June, maybe even early July, and we come back when that program begins or that initial application begins to break down, we need get one or two inches tall with another non-selective post in additional pre-emergence material with it.

And then the third option I call a delayed pre, we go in in Western North Carolina with a mid-March application of just a non-selective post-emergence burn down, and basically, that eliminates the winter annual weeds that are present at that time.

And then we don't go back until the soils warm up enough that we go to seeing emergence of things like, you know, crabgrass, maybe some, you know, pigweeds, and those things begin to emerge.

And here that would be, you know, somewhere in early May.

And we put out another non-selective post with the pre at that time and we call that program with delayed pre.

- Wayne, do you have any of this kind of summarized in some sort of fact sheet or something that's online?

- Yeah, the probably the best resource is, if you're familiar with the Southern Region Small Fruit Consortium, those IPM guides, there's information in there on timing of those herbicides and some tables.

You can go to smallfruits.org.

And at the top of the website there, click on IPM Guides, and it's got a complete spray guide for a bunch of grapes and muscadines, and those recommendations for herbicides are in those publications.

- Great. - With timing information.

- If you have time, Wayne, before we close up shop for the day, if you could put that link into the chat, that'd be awesome.

- Okay, I can do that. - Thanks, Wayne.

- [Hans] I'm getting it right now.

- Okay, cool, thanks, Hans.

Up, looks like Luke beat us.

Okay, thank you. We got several people on the task.

That's great.

All right, panelists, we are coming upon less than 10 minutes to go.

Anything that has been said here that, you know, resulted in you wanting to say something or "Oh I wanted to add context or experience to that." Otherwise, I'd ask panelists....

Well, I'll stop there.

Does anybody have any questions or other comments?

- I think one of the themes of today was just talking about how important timing is, and somebody had even talked about sucker management and I think the same goes for so many tasks in the vineyard.

If you're able to catch, you know, suckers or if you're shoot thinning when shoots are really small, if you're trying to go non-chemical with that management, you're going to have a lot easier time than when you're trying to, if you were to try to tackle sucker management far down the road, and similar with weed management.

- For sure.

Good point, Madeline.

Okay, then I would ask colleagues that are on the panel but not lead panelists for this webinar.

Were there any questions throughout that anybody had been monitoring that they think should be brought up?

'Cause we have about five minutes.

I just saw one coming relatively late...

Oh, go ahead, Maria.

- This is gonna be part and parcel to cold climate grape growing, but there was a question that was referring to under-vine ground cover use for those vineyards that require graft union protection, in which case annuals are an option, but we really only discussed perennial ground covers and I think this is pretty much only relevant to like maybe upstate New York and Ohio on this webinar.

I don't know if any other region here really does a lot of soil hilling for graft union protection for vinifera, but I thought that was a relevant question that we didn't really spend much time talking about in terms of under-vine ground cover.

We talked about perennials but not annuals.

- Yeah, so I addressed it briefly in the chat to that one specific question, but yeah, for hilling-up and all the work that we've done and Justine had done with growers, as long as you're using annuals, so you don't get at most grasses.

I mean you it you plant it in the spring, you take it up in the fall, and you don't get a massive root system.

And so you can still hill-up.

You have chunks of sod so it gets a little clunkier.

I mean you get bigger chunks and things like that.

You don't necessarily get this easy roll of soil, necessarily, as much, but it's still very doable to hill-up.

It's just, you have to go a little slower too.

- Are there any particular annuals besides buckwheat that have come around in the past, I don't know, five, 10 years or so that have been a broadly recommended annual?

- The buckwheat is the one that kind of got the best results from a lot of Justine's work, just because it establishes quickly so it can outcompete weeds pretty quickly.

It's relatively inexpensive, and it didn't really impact vigor at all.

So if you want something that just kind of outcompetes weeds but doesn't really impact vigor, then it's a good option.

The biggest cover crop they saw that did impact vigor was actually chicory, and they were using kind of a dwarfed version of chicory.

So the stems didn't grow three feet tall, they stayed 18 inches or so.

And that had the most consistent impact on vigor.

They had done some things with like alfalfa, which was also very invigorating, but I wouldn't wanna use alfalfa as a cover crop necessarily.

And again, if you have to hill-up, that root system is crazy.

So I think there are some other options that are out there but buckwheat seemed to be a really good one.

And actually another really good option, honestly, outta like all the data was just plain old ryegrass, annual ryegrass.

- That's a good point, thanks for bringing that up, Maria.

Alice, there was more than one question about organic herbicides that I saw come up, and I did not monitor the chat.

I was busy kind of trying to keep questions in line for our panelists here, but Alice, can you comment.

I think there was a question about cost of it, effectiveness of it for organic herbicides.

Do you have experience with that that you'd like to comment on?

- Just a little.

You know, I would defer to our weed scientist on Long Island, Dr. Andy Senesac.

He's done quite a lot of work with them.

Oh, I've used AXXE, A-X-X-E, and I've used Scythe.

Scythe isn't organic but it's close, close to it, anyway.

Generally, on Long Island, you know, on younger weeds, just like all the other recommendations, you can't spray big giant weeds, especially grasses and dandelions, and expect to get any very good control.

But it gives about two weeks worth of protection.

Maybe three weeks if it's a little dry, you know, two weeks if it's raining, and then they grow right back.

I mean, you'll go back in a couple weeks, in some cases, and it looks like you haven't sprayed anything.

That said, you know, for some people, that's the main option they have.

I don't think I've used vinegar.

I don't really know if it would...

I see there's a question, would it increase soil acidity?

I haven't really used vinegar.

I would defer to the weed scientists on that.

- On the organic herbicides, I've not done a lot of work with it myself.

Katie Jennings, in our department, has done some work with these.

And, you know, the couple of things, coverage is extremely important because they are contact materials.

So you know, you look at something like even the Scythe that Alice mentioned, which is a pelargonic acid, high volumes of vinegar, high volumes and high concentrations.

I don't know about the acidity in the soil but the coverage is gonna be extremely important.

So you're gonna have to put out a significant amount of volume.

Weeds have to be one or two inches tall, and go ahead and expect on perennial weeds, regrowth is gonna be a big concern.

And even some of the annual weeds, depending on the species, regrowth can be a problem.

But yeah, about two weeks is what you're looking at there.

- And I know a lot of the organic fruit growers that I've worked with in my area, which there's not a lot, but they have said that Homeplate, which is a product that contains caprylic acid and capric acid, and it is something that, I think, it's a little bit newer and more effective.

I haven't personally used it, but I don't know if anybody else on the panel here has comments on that as well.

But that's not an acid that's a fatty acid, so that's not technically acidic even though it has acid in the name.

- You know, if I wanna do an organic weeds program, I would probably be thinking about mulches in conjunction with some of these organic herbicides because the mulch just give you a lot of suppression and then you can manage the things that would emerge with these contact organic materials.

Just a thought.

- Great.

Well, we did start a little late today so let's take one more question, and Jo, I'm gonna ask you to maybe kick this one off, not that you're a viticulturist or vineyard specialist but I think that last question that came in, any tips on methods or equipment for incorporating seed under-vine into established vineyard soils?

I know that that could be tricky sometimes when you're working under-vine and trying to get some cover crops established.

So if anybody wants to add context or an answer to that, that'd be great.

- Yeah, one thing just kind of a basics of cover crop, cover cropping is the seed sides really influences how the suitability for broadcasting versus drilling, so annual ryegrass and one that vegetable farmers, that is like the...

And teff, if you're in a climate, those have great success with broadcasting 'cause they're very small seed size.

So that might be a good fit for some of these vineyard systems so you don't have to worry about it because obviously moisture really influences whether you're gonna get a good catch for some of the larger seeded crops.

So maybe I'll just say that.

- [Cain] Yeah.

- Cain, when we were experimenting with a couple different methods to seed under-vine cover crops, we tried a couple of different things, and that was by far the biggest challenge is kind of how do you make sure that you get good seed contact.

My experience is exactly what Jo was saying, that when we would put out annual ryegrass seed, as long as we got a some rain within the first few days after we put it out, it took off, and we got a pretty good stand of it.

Buckwheat didn't do anything.

And so the best thing I could think of for people who have the equipment without having to kind of create something new is just, basically, if you have some kind of cultivator that can just basically kind of brush the top of the ground somehow and hopefully you just kind of get that very top couple of centimeters of soil to kind of roll over without necessarily dragging all your seed out of the vineyard, that's the best option I could think of.

We would talk to some people about could you like jerry-rig something that would have like chains that would drag behind it so that the soil could roll and whatever.

And I mean people have tried...

I know a couple people have tried different things but the kind of the cultivator idea was the best, I think, I could come up with without having to come up with something new.

But I think Jo's right, for a lot of those cover crops, it's gonna be the difference between success and not so successful.

- Did you see Rob Russell's comment banded early season hydroseed?

- Yeah.

We had a grower who rented a hydroseeder one year and it did work.

He doesn't do it anymore though 'cause it was really expensive and it took a lot of time.

But it can work, I mean it's all about scale.

I mean somebody else had a question in here about using fabric mulch under-vines.

If you have a half acre vineyard, sure, go for it.

I wouldn't dream of doing that on a 10 or 20 acre vineyard.

- One thing- - Well- - Oops, sorry.

One thing with annual ryegrass, just to add real quick, we always say, this is the part where it's like really important to treat your cover crop like a cash crop and get good seed because there's some annual ryegrass cultivars that have some herbicide resistance.

So if you get some bin run seed or something VNS, you might be putting something out there that you're gonna have issues managing, or be more on the perennial spectrum of annual ryegrass.

- Yeah, good point.

Well, look, I put Tony Wolf and Gill Giese, author to "Vineyard Floor Management" publication.

I think some of you have probably read it.

I put that in the chat.

What I learned after...

What I really understood about after reading that was cover crop management, well, inter-row, but especially under-vine, has to be intentional.

It's a management, right?

And I've been in some vineyards and this isn't a call, whatever, you know, call out growers.

I mean, I get it.

It's like where they just let things grow and they just stop managing it.

And I would say that that's not cover crop management.

And it gets kind of unwieldy and it's hard to manage.

So it has to be an intentional management strategy and there's some nuance to it.

Right, Alice? (laughs)

All right. - I think we all...

- Well, go ahead, Alice.

- We could talk about this for the next three hours I think.

- Yes, yes, yes, yes, yes.

Okay, well, look, thank you.

Thanks to our lead panelists.

If you wanna put the the clap emoji, I'll try to do it here.

Anyways, really grateful for all of our lead panelists for this webinar.

Thank you so much and thank you all for joining and participating and engaging throughout.

Our next one will be March 11th and it'll be on disease management, so don't miss that one.

In the meantime, stay warm.

Looks like some warmer temperatures are ahead next week.

Yeah, fingers crossed.

- Thanks everyone. - Bye everyone.