169: Do You Need to Crop Thin Your Vineyard?

The study of whole vine physiology does not isolate one variable in grape growing. It looks at many factors at once including data collection in the plant, in the environment, and in fruit. In her research, Patty Skinkis, Viticulture Extension Specialist and Professor in the Horticulture Department at Oregon State University helps growers improve their farming practices by evaluating the plant growth stage, shoot growth, pruning weights, yield, cluster weight, berry size, and fruit chemistry. Patti shares her surprising results from a 10-year trial on crop load management. Grower trials found there was very little difference with crop thinning in both fruit and wine quality.


Get More

Subscribe wherever you listen so you never miss an episode on the latest science and research with the Sustainable Winegrowing Podcast. Since 1994, Vineyard Team has been your resource for workshops and field demonstrations, research, and events dedicated to the stewardship of our natural resources.

Learn more at  


Craig Macmillan  0:00 

And our guest today is Dr. Patti Skinkis. She is viticulture extension specialist and professor in the Horticulture Department at Oregon State University. And really excited to have you here tonight. Welcome Patti.


Patti Skinkis  0:10 

Thank you. It's great to be here.


Craig Macmillan  0:12 

So there's a concept that's kind of out there. I'm familiar with the words, but I'm not entirely familiar with what it means. What is whole vine physiology?


Patti Skinkis  0:21 

Whole vine physiology is really looking at the study of how the vine is responding to its environment. And it's not looking at just one component, it's looking at how the entire vine is responding. A lot of times, whole plant physiologists are more applied plant physiologist, rather than more fundamental in that they're looking at exactly how that plant is responding to its environment. And sometimes that environment is things that we do to it, such as the studies that we do and in crop management, as well as fine tuning, looking at some aspects and and trying to understand how it links to other aspects of how that plant is responding to its environment. But we're taking the plant as a whole.


Craig Macmillan  0:59 

That sounds kind of difficult. It sounds like there's a lot of variables there. How do you do you identify a couple of variables? And say, we're going to look at these? And if so, how many might you be able to handle at a time? You know, I've done a lot of research and statistics. And every time you add something the whole system gets exponentially more complex. As an example, what kinds of things might you look at with a plant, you're going to modify one variable in the environment? But then what other kinds of responses might you look at?


Patti Skinkis  1:23 

Well, doing whole plant physiology work is difficult in it's the nature of the beast, when you're looking at the entirety and taking it in as a whole. I like to address this question from a standpoint of what it is not. And partly because I work with a lot of other scientists who work in biochemistry or fruit chemistry. And they always want to isolate the one thing or two things that can explain what we might be seeing in fruit chemistry, or in plant nutrition. But the reality is, we have to accept that we can't explain at all that it's a whole package. It's not one specific mechanism. As a result of that we look at a lot of things, we try to understand how one piece will influence another piece. So a lot of times in the studies that I'm doing, we tend to do a lot of data collection on the plant as well as in the environment. And then the fruit, it means that we do a lot of data collection, maybe more so than other scientists would if they are just looking at pathology or insects or some other aspect, we monitor the vines phonology. So the growth stage, we monitor shoot growth early season, and then we switch to leaf area, we do pruning weight. So all of those are giving us an idea of the plant size, how much it grows. And then of course, we look at yield, and then yield components, which takes it through looking at cluster weight and rakus, length and very size. And all of those just take a lot of time. And then of course we get into the root chemistry. And it's not just you know basic ripeness at harvest, we then go into global analyses of key compounds like nitrogen and the phenomics. We do collect a lot of data and ultimately, what refines what we're looking at is kind of we always write our research questions to say, Okay, here's what we're going to target. But then a lot of times, we end up coming back to doing all of those measures, in part because we know that a lot of it is interlinked. And so it is a lot of data collection, a lot of complexity. One of your questions was how do we deal with all the variables? And so that really, you know, from the standpoint of doing whole plant physiology, where I'm working in a vineyard, I'm working typically in research farms, or on grower collaborator sites. And when it comes to controlling variables, that's when we try to do as much as we can. So can we pick a trial site where we've got very healthy vines that we know are consistent, rootstock consistent soil as best we can consistent, slope, we try to even avoid hillsides if we can. And if we can't, then we block accordingly. So we're doing a lot of re study evaluation of the site to know what can we at least try to eliminate instead of creating more messiness, in a system that we're trying to understand.


Craig Macmillan  4:02 

You mentioned work that you're doing what what kinds of things you're looking at right now.


Patti Skinkis  4:05 

So right now we have a number of different trials, but main work is in vineyard floor management rootstocks and yield management. And so those are the three primary areas that I'm working on currently.


Craig Macmillan  4:19 

What do you do with root stocks? I know that wasn't the topic you and I talked about earlier, but I'm curious about that, because that's a fixed thing. Pick the root stock. And that's it forever. I hope I made the right choice.


Patti Skinkis  4:30 

While we're doing a rootstock trial, and I'm lucky that my predecessors had established a block in 1997. So we have a well maintained mature trial with 19 rootstocks that are include Pinot Noir on those 19 rootstocks and owner divines. And so we came back thinking okay, there's a lot more questions coming from growers here in Oregon about what rootstocks they should be using climate change is definitely occurring. We see warmer, drier seas Once and while most of our vineyards can be dry farmed in the Willamette Valley, many people are very concerned about being in sites that have limited soils or not as luxurious soil. So we call them in terms of soil moisture as and nutrition, but also there, even though we're dry farmed, we don't necessarily have access to water. So if they needed to irrigate and may not be be possible if they're getting into different vineyard properties, we decided to embark on looking at this trial that has been in place at our research farm and come in and start looking at plant water stress and comparing those to our standard rootstocks, which happened to be in our trial. So we have a whole mix of more drought tolerant root stocks as well as our standard vineyard rootstocks, which are mostly vigor reducing, not drought tolerant. And those are what most of our industry is planted on, at least here in the Willamette Valley. And so the the trial was really done to see, okay, if we do switch to root stocks, what does it look like for yield for canopy size. And we, of course, looked at the the water stress response as well. And so we've been monitoring over the last four years different components of that rootstock trial, and the last two years being looking more in depth at plant water stress as a result.


Craig Macmillan  6:12 

This is kind of a practical question, in my mind when we're talking about things like yield changes, are you pruning like this rootstock tell? Are you pruning everything to the same bud count? Are you leaving the same number of growing points on every mind?


Patti Skinkis  6:22 

That is a great question, because it's such a mature trial, the results of rootstock are clearly visible. So for the most part, we can prune to the same number of buds per plant. But in some cases, we have to do balance pruning, because there's so little vigor, so for example, with Riparia rootstock, it's very degrading. And so we cannot do the same number of buds as we can, for 1616 or 1103 or 140R for the most part, we try to keep to the same, but number. But again, we have to balance prune some of those that are clearly very invigorated by the rootstock.


Craig Macmillan  7:00 

You've been doing work on crop load recently, which I'm very, very, very interested in. What is it specifically that you're looking at terms of variables, manipulations, then also very user? How did this come about? How did this become a research question they became interested in?


Patti Skinkis  7:12 

The crop load work has been a part of my research program now for about 12 years. And I started out doing that work, because I saw a lot of focus on reducing yield in the Oregon industry. When I first came here, it didn't make sense to me, because our vines are very healthy, we get a lot of leaf area, they're well managed. And it's not high shoot density. I mean, everybody has shoot thinning to the the required three shoots per linear foot, or three to five at most per linear foot. And so their crop thinning at that time to one cluster per shoot, which is about a 40% crop reduction, and they're doing it late in the season. So around lag phase, of berry development. So I embarked on a study to studies timing by intensity trial in 2010, through 2013, and looked at just when should they be cropping and by how much. And we found that from that study, there was very clearly no benefit to really doing it early, we could do it late in which was my surprise, I thought if there was going to be any impact that would be necessary to hasten ripening, then, and that's always our goal, hasten ripening and increase quality because a lot of growers believe we need to do it to get our harvest end before the fall rains, or just to improve what they call concentration.


Craig Macmillan  8:34 

Real quick, just talked about Oregon in general. So if I've got Pinot Noir in the Willamette Valley, how much danger do I have from rain coming into harvest? Is that a common problem? Is that happen occasionally, but enough that it's an issue?


Patti Skinkis  8:46 

Certainly 10 to 12 years ago, it was a real and present danger every year. And now in recent years, it's been less of a concern because we become warmer and we tend to be harvesting earlier. So when I embarked on this trial, you know, it's always a concern. And it certainly is at the forefront of most of the longtime grape growers and winemakers as we get new people and I think they're willing to do more hangtime. So there's always this dichotomy of wanting hang time, but always the threat of, of rain, and we just don't know there's no crystal ball to know how long we'll have. But typically, we're seeing more dry September's than we have in the past. Usually, by the time we get to October, everybody's you know, they're worried about the rain coming, it's a percentage chance of having rains during harvest is significantly higher. As we get into October when we were doing the work. We wanted to see, you know, should they be thinning because their vines are behind and they need to thin earlier or do we thin later as a means to kind of have them catch up. And what we found in those first studies was that did not really make a difference to crop thin, early, and in fact, it made more vigor and we deal with a lot of over vigor in the Willamette Valley, so there was definitely not worth cluster thinning preboot Boom or at bloom or even at fruit set and waiting to leg favs was completely founded. The second thing we found is that the cluster thinning really didn't have had much of an impact at all. The only year it did was in 2011, which was a, a cooler season, and a very big crop. And we were very late. So about a month later in everything. And so we did see a benefit of of cluster thinning in that year where we kind of reached a maximum level that we would expect that these plants would be able to carry through ripeness. So when I did all of those trials, I shared it with growers, they were very excited to hear the results growers much more excited than winemakers about the results. But their answer kept being to me, you know that that's great, you got an answer for those two vineyards where you did that work. But those are special cases or only those vineyards. And I thought, you know, is bigger. When we look at crop load management is such a entrenched practice that you crop then in high in cool climate regions for high wind quality. Restricting crop is important. And that's something that one study here there is not going to change. And the only way to really change it would be to embark on a very large project that directly engages growers in that process, not only growers but winemakers, too, and doing that work on their farms. So prior to my first crop load studies even being finished, I started embarking on this idea of a much, much more grandiose project that involved a lot of partnership with industry directly. And so over two years, we had planned the study, working with growers on an advisory committee and said, Okay, here's my idea, what do you think, will you join? And how can we make this work. And so that was in 2010, I basically started having those conversations while I was also doing my smaller scale projects. And as a result of that, we started what's called the statewide crop load project. And we ran that for 10 years from 2012, to 2021. So 10 growing seasons, and we solicited partnerships with growers, they were all volunteers, and they came mostly from the Willamette Valley. And they basically did the cluster thinning or crop thinning to their determined levels that they wanted to use over as many as 10 years. So so they had to be in the project at least three years if they could. And the the goal was for them also to make wine. And so sometimes the winery that owns the vineyard made the wine sometimes other folks or other people who bought the wine made the wine, the wines had to be made. And so the process was that the growers had to do the thinning and collect data per protocols that my lab gave them. And then they had to produce the wines that then we did some analysis on. And we did the analysis on fruit as well.


Craig Macmillan  12:43 

These growers, were they doing different different levels of thinning on their property, side by side, and then you were using site as rep. I'm totally geeking out here, but or were they designed as replicated experiments on site or just this ranch does this and this ranch does it? How did you how did you set it up? Because that's hard?


Patti Skinkis  13:01 

Yes. So we set it up as more robust is what I wanted, I wanted to be replicated on site. And then so each trial is its own trial. So each grower had to replicate it in a randomized complete block design in their individual vineyards. And so that at the end of the day, we could analyze their data within their vineyard, as well as across all vineyards. So it's replicated at least three times. In fact, most vineyards were replicated far more than three times, but I only made them get data on three reps, because they've quickly realized that they could divide their vineyard up into as many treatment reps as they wanted. But then if they would collect data on all of those, it would just be time to time consuming. So we did minimum of three reps of data collection.


Craig Macmillan  13:45 

You are my statistical hero. Now, I've had to do these. And what you're doing is just the gold standard gold plated. I'm so happy. I can't wait to find out what you found out because you did it exactly right. I'm so struck, anyway continues to have. So this is great. So the industry they're doing, they're doing it on site. They're collecting data.


Patti Skinkis  14:03 

They're collecting the data, they hand in the data, they make the wine, and then we did sensory for five years with the Oregon State University. My colleague here Elizabeth Tomasino led sensory trials with winemakers. And so we did the first five years that way. And then the second five years, the group as a whole decided they wanted to switch gears and focus on just their internal sensory. So in house evaluation of their wines, which I had hoped that they were doing the first five years, but it turned out unless you gave them a protocol, they did not collect the data on it. They were collecting data, but they weren't sharing it. So that was my the second half of the study. I thought okay, we'll shift gears and part of that was, you know, ideally, someone would say, Well, why don't you just stick it through with that the sensory analysis at OSU? Well, it costs money. And this project was, you know, for a 10 year project, we had to try to save money as best we can because no granting agency wants to get have money for 10 years of research. And so we decided, you know that we were not going to continue with that and, and shift really to the focus of the growers. I mean, that's who's making the decision growers and wineries, I should say, making the decisions about the quality of the wines as a result of thinning to make their choices as to where that fruit goes and make future plans on crop thinning. And so we really took it towards that first five years looking at do we see a difference? Versus and doing some descriptive analysis to the second five years still trying to see asking questions about difference testing, and about descriptive analysis, but now taking it from a standpoint of who's making this decision about these wines, and they're tasting them. And so really encouraging growers to taste them and wineries to taste them if they had not already done so.


Craig Macmillan  15:51 

And what kind of things did you find out?


Patti Skinkis  15:53 

So the power of doing the research in each individual vineyard meant that I could do the stats for each vineyard and hand them a report of their project. And each year as we went through the project, we would share the results with the growers. So we went every year crop year that we closed, we shared the viticulture data with them. And the results were there's very little difference with crop thinning over time, we figured okay, this might be a you know, impact of, you know, over time, you know, we always hear from crop consultants or vineyard managers, if you keep cropping heavy, you're gonna have to add more inputs. We didn't see that, generally speaking, we have some vines in the study that were full cropped, never thinned for 10 years. And they did just fine. There are some things that we did find, you know, generally speaking in any one vineyard with lag phase crop thinning, there was very little impact on and fruit quality. So fruit composition is mostly what we had data for. But we're talking bricks, pH titratable. acidity, very rarely were they different until we got into years where our base yields were just much higher than normal. So we saw that in a year where maybe our yields were double. So cluster sizes were bigger fruitfulness was higher than we saw some impact, but it wasn't every site, it was maybe a third of the sites, the results really came that most sites there's very little difference in that end wine quality and when I'm sick or fruit quality, I should say. So Brix pH ta Yanes. So use this global nitrogen, we looked at total phenolic total tannins total anthocyanins and for the first five years of the study, we had ETS labs run their whole phenolic panel, and as well as their ripening panel, and we saw very little differences in there might be some years that a certain vineyard had a difference. But then after that year, they didn't have it anymore. So it was very inconsistent. And it's not to say that thinning did nothing, but it was very, very limited in the results to say okay, we are definitely changing x when we crop then we didn't see that. And that was a real eye opener. So that was the fruit. So I should say that was what the fruit told us now when it came to the wine. For the first five years, our sensory panel led by Dr. Elizabeth Thomasino, you know, here at OSU, she was winemakers. So the winemakers were Oregon winemakers, the results of those years was that crop level was not what drove the quality or the perceived preference of wine, it was really the vineyard or the the winemaker from a given site, there was never really any clear identity of higher quality or higher concentration or higher certain descriptive analyses for a crop level. So it became clear that there wasn't very much difference. And that was one of the reasons the real reasons why I think the collaborators wanted to go a different route because they were not seeing seeing much difference. And so they thought, Well, maybe if we start looking internally, we see differences. So the second five years, we did ETS labs didn't run the analysis, I ran those in house in my lab. And so we we did the same measures as ETS lab from from the standpoint of global analyses, same thing, very little difference. But when we switched to looking at the impact of wines from getting the data from the winemakers, number one we had a really hard time getting that data and so many collaborators, they followed through, and they didn't do the paperwork, or they didn't ever follow through with us. And so it was really challenging to get the data but from those who did follow our protocols, the results mirrored our first five years which was there was very little difference. And it was very hard to tell a difference in in the wines. Now they knew that there was a difference. So when we asked him for a difference test, we said can you tell the difference? Of course they said yes, because they knew they were blind tasted but they knew if any, it was an evaluation, so it was a little leading there. But when it came down to describing what they were seeing in the wines, comments like all of these wines are lovely came up and so there wasn't a clear distinction on quality, that one was very clearly bad. So we did a two step approach, we had them first taste some blind, do their ratings individually, then they would find out the identity of the wines. And then they as a group, they would talk about them. And it always came out that after they knew the identity, that's when they were changed their mind about any given wine that they rated initially. So what we see in the pattern of the results was that they were willing to not completely downgrade the higher yield. Unless it was the no thin. If it was no, thin they felt very uncomfortable saying, Okay, we don't need tp thin, but they felt more comfortable saying, Okay, we like this one and a half clusters for shoot, which is a one to one to thinning pattern, which is about a 15 to 20% crop production. And I can understand that as a winemaking team, as a grower team, you want to be conservative, you want to be careful, you don't want to say okay, yeah, so I found a lot of what they were answering on was more future looking rather than what's right in front of you right now. Like looking at, okay, here's the wines use the full crop or no thin and here's your one and a half cluster, one cluster pursuit, you didn't find them all that different in the descriptive analysis. But now when you're, you know, the identity, then you're saying, Okay, we're not going to take these notes into our highest here. We're going to leave those aside. So there's some bias.


Craig Macmillan  21:20 

Yeah, well, no, absolutely. And that's one of the things I love talking about. And you know that the winemaking techniques were consistent across the lots. Yeah, so it wasn't canopy management manipulations or anything like that.


Patti Skinkis  21:32 

Yep. So both in the vineyard and in the winery. So when we said they did this in their vineyard, they couldn't do things differently in the vineyard of two, one or the other. And we actually picked up an issue. And that some you know, when you do crop thinning, you have labor crews come through and leaf pull. And we recognize that early on that some growers just wouldn't leaf pull as much in there no thin so we had them go in and leaf pull the same as they would for their other thinned to remove that that issue. In the winery we told them they had to make all their wines the same. And we did not have them do for example, long barrel aging in oak barrels, they could make the wines how they normally make their wines. But they we did not want them to go to barrel. And so they had to be bottled and then tasted after about a year of bottle aging.


Craig Macmillan  22:21 

Interesting. Maybe I missed this but you were talking about the thinning protocols meaning like around bloom time and round lag phase. What about at verasion that's at least around where I'm at in Central Coast's is very common to do crop dropping about 85% verasion was that a component what you did was or verasion era?


Patti Skinkis  22:40 

We did verasion time point included in our time core study that was before we launched on the big project. So when we did the big project, we decided we would just go with what growers always do, rather than adding more time points. And so they just did in the statewide crapola project just did like face for our crapload are thinning by timing by intensity trial, we did include verasion for that time for that trial.


Craig Macmillan  23:08 

And that green drop is at about the same, like at about 85% or somewhere in there. What was the trigger for the drop at verasion?


Patti Skinkis  23:16 

It's post lag phase  was done when there's about 50% color.


Craig Macmillan  23:20 

Okay, there we go. Okay, that makes sense.


Patti Skinkis  23:22 

The verasion time point is or late, even later, is oftentimes done in Oregon as well. But usually it's a result of either thinking that they have way too much crop out there for their target yields, or disease, so botrytis.


Craig Macmillan  23:54 

And when you're talking about these different crop load levels, I would imagine that disease pressure would be an important issue, especially in Pinot Noir in Oregon, I would think.


Patti Skinkis  24:04 

So that's a great point, because some people, you know, will crop thin because they want to avoid overlapping clusters. But in our trial, what we did was we said, Okay, for the no thin, we want you to just do things like you've always done and some growers would say, Okay, now when they're, we're sorting that fruit, should we sort out at the sorting line, you know, and I said, No, you know, if you do sorting line for that fruit, make notes, you know, obviously, you don't want to make a bad wine because there's too much botrytis. But basically, what we had them do was if you're going to sort through one you have to sort through the other and don't just have preconceived notions that you're going to have to sort more in your no thin than the others. And we always in the data that we got in we looked at as we dissected clusters, we looked for detritus, and what we found is in most years, there is not an impact of having no thin having more disease. Now Could there have been sure if there was years with very heavy crop yield, and with high shoot density, but most of our vineyards have when we looked at all of our data we got in and one of the quality control checks is, what was their shoot density, and almost everybody's following in that perfect shoot density. And so there wasn't that necessary, necessarily that much fruit on their vine. So they're all cane pruned. And they're all shooting for that shoot density of between three and five shoots per linear foot. And we're more on the three end. So we can see that in all of the data. So it's not surprising to me that we didn't see disease issues as a result of leaving that full crop on there, why we didn't see a lot of differences in this trial, I should provide some context here. Without you know, the amount of yields were not terribly high, with that kind of shoot density. So single canopy, low shoot density, we're at a pound per linear foot on average full crop in only a couple of years. During the 10 year period, we're over one and a half pounds per linear foot. So the tonnage that would come off of that. And I always put talking pounds per linear foot because our vineyards were in many different spacing and shoot and vine density. So you we can't talk tonnage, what we found in looking at the data that there were clear years where once we had yields over one and a half pounds per linear foot, then we saw some benefit of cluster thinning. But those years where we are barely at one or just over one, there really was not a benefit. And of course, that's because of the canopies being well maintained. The shoe density is not too high cluster density is not too high a cluster size themselves are smaller.


Craig Macmillan  26:36 

What has been the reception so far, for both growers and winemakers because this goes a little bit against conventional wisdom, at least in my experience?


Patti Skinkis  26:45 

It goes a lot against convention,


Craig Macmillan  26:47 

I'm trying to be polite.


Patti Skinkis  26:51 

Well, the nice thing is, you know, because along the way of doing a 10 year project, I was always giving presentations as the new data set came out and people in the industry would hear me give presentations about it. But I think the strongest impact was seen because I had grower collaborators, they saw the impact in their vineyards and in their wineries. And what we found was that people are much more willing to increase their yields. My answer is not that they they stopped crop thinning, surely that didn't happen. But they were allowed to evaluate and recommend higher yields than they had in the past. And this is a data set that was really hard to get directly from people. But we see it in our state yield reports that basically they've gone up 25% The yields have for Pinot Noir. Since the work has been started. When I talk to people who are contracting fruit or selling fruit. They said they definitely see that winemakers are more receptive to vineyard owners and vineyard managers recommending higher yields. And they're no longer saying it has to be one cluster per shoot, or it has to be two tons per acre. And I would say the 25% increase in yield is conservative I when we did ask the collaborators about the project, we asked them about three quarters way through the project said, What do you feel comfortable doing as a result of this work. And they said, we feel comfortable adding another half to one tonne per acre, which is about a 20 25% increase from what they've done before. And so that's really is really astounding, I think any if I hadn't done the project this way, I don't think that people would have been able to understand the true impacts or lack thereof, of doing cluster thinning. So it provided with them with more evidence that they can take this risk and or they they didn't feel like it was as big of a risk to leave more fruit out there.


Craig Macmillan  28:48  

Which reminds me I know it's difficult to talk in terms of tonnes per acre. So we can talk through the linear foot, but the range in your work from the most aggressive thinning to the unthinned. What kind of a range is there, how big of a difference in terms of the crop load?


Patti Skinkis  29:04 

In terms of the yield that they've had in vineyards, the lowest crop thinning level that growers did was half cluster per shoot. So that meant thinning pattern 0101 or 1010. The yields on those would be as low as one and a half tonnes per acre. But it depends on the vineyard that it came from because one of the vineyards that did it was a very high density. So their yields were actually pretty high even still, but I'd say the max that we got in any vineyard was probably close to about eight tons per acre. So clusters per linear foot were always pretty consistent unless they went to a double canopy. So we did have one collaborator in the study that was on a GDC or Geneva demo curtain. But that vineyard was actually pretty degraded so it didn't explain higher yields. What we saw was higher yields were from those vineyards that had high density meter by a meter and a half spacing. Normally we were at on a pounds per linear foot bed He says that the extremes were about two to two and a half pounds per linear foot. And so for those vineyards, they could be pretty substantial if they were in the high density.


Craig Macmillan  30:09 

We are running our of time. So I want to ask you a couple of kind of closing questions. Is there one piece of advice or insight or one thing that you would tell a grower regarding this topic.


Patti Skinkis  30:18 

It all depends on what you have for your vineyard, your rootstock, how the vines are trained. So the biggest thing that we came up from this research is that we don't want to tell people that they have to crop them or that they don't have to crop them that and that we don't have a real answer of how much it has to be. But one of the things we do have clear in the data is that we know when we've gone too much, a lot of people think that that's every year and it's not every year because of our climate is so variable, we don't know what we're gonna have, we can go and quantify fruitfulness. But really until we get through fruit set in June, we don't know what our yields look like. And so I always tell people to keep monitoring your printing weights, your yields, calculating your your your Rivas index or the crop yield printing weight ratio, and just keep monitoring it for your site to know what Max is going to be because some vineyards can handle more than others. And the last thing I would say is quality is dependent on the vineyard site and how that site is managed. And even if you have a good manager, you are never going to have a really high end wine if you don't have the right site or the right you know, selection of clone rootstock etc. So it all plays into that quality and just crap any is not going to guarantee you a high quality wine.


Craig Macmillan  31:41 

Once again. It's a great big world with lots of different variables all of which have to be considered. I want to thank my guest Dr. Patty Skinkis she is a viticulture, extension specialist and professor at Oregon State University in the Department of Horticulture. Real pleasure this has been really, really fun. Like I mentioned, this has actually been kind of a pet topic of mine for a long, long time. And I'm really happy that you've been doing this work and I hope more people learn about it.


Transcribed by