PRECISION

VITICULTURE CASE

STUDIES UAV-IQ’s Due Diligence Primer

ABSTRACT This due diligence primer contains a selection of published

studies which document the economic benefits of utilizing

remote sensing to practice precision viticulture.

UAV-IQ ©2015

1.

2.

An economic analysis of this strategy is given in Table 1 which shows that both the grape grower

and winemaker derive a significant benefit from selective harvesting. Note also that the costs

(Bramley and Lamb, 2003) of implementing PV in this block amount to 0.6% of the price

received for ‘C-grade’ fruit. Thus, even if these costs were borne entirely by the grower, they

would be more than offset by the increase in the value of grape production achieved through

selective harvesting.

3.

Source:

The Commercialization of Remote Sensing and GIS for Vineyard Management: A Simple but Powerful

Application of Change Detection

Authors:

Ryerson, R.A. ; Schwebs, S. ; Brown, R.B. ; Boles, S. ; Duncan, M. ; American Society for

Photogrammetry and Remote Sensing

Presented At:

American Society for Photogrammetry and Remote Sensing (ASPRS) annual conference 2008, “Bridging

the horizons : new frontiers in geospatial collaboration” ; Portland, Oregon; April 28 - May 2, 2008

Journal:

PROCEEDINGS OF THE ANNUAL CONFERENCE - AMERICAN SOCIETY FOR

PHOTOGRAMMETRY AND REMOTE SENSING; 2; 606-615

ABSTRACT

Remote sensing and GIS have been used for day-to-day vineyard management in a quasi-to-fully

operational fashion in the Napa Valley area of California (Greater Napa, Sonoma, Lake and Mendocino

Counties) and several other regions of the world for the past five to ten years. This paper reviews some of

the key papers in the literature and describes the way in which the tools have been used in a fully

operational environment. The focus is on their use as a special but simple case of change detection over

time – both year to year and over a season. These applications have ranged from thermal sensing to

identify areas prone to frost damage in the Niagara Region of Ontario, to the use of high resolution

airborne imagery for viticulture research and management in the in the Napa Valley and Oregon wine regions of the United States and the Niagara Region of Canada. Monitoring changes over time has proven

to be one of the most valuable contributions of remote sensing for vineyard management. Given the

financially compelling reasons for using remote sensing in vineyard management in many regions of the

world, the challenge in commercializing such services in other regions has been surprising.

Excerpts:

The answer to the question posed in the title of the 1998 paper by Johnson et al – “Can geospatial

technologies help produce a better wine” was a definite “yes.” Indeed, Robert Mondavi Winery

was able to use the work by Johnson et al (1998) to produce reserve quality wines from a plot that

had never before done so. The results that we have been told about in site visits to Napa and work

by a co-author suggest that such results are no longer limited to research projects. GrayHawk has

been helping deliver similar results to wineries (two of them with over 800 acres each), vineyard

management companies, as well as smaller growers with vineyards as small as 2 hectares.

THE ECONOMICS OF REMOTE SENSING

Vineyards are expensive. In the Niagara Region of Ontario the Grape Growers of Ontario suggest

that it costs $24,000 exclusive of land costs to bring one acre into production. Land in the Napa

Valley is said to be among the most expensive agricultural land in the world. Recent real estate

listings put a value in excess of $250,000 per acre on some vineyards. The emphasis on and

importance of increasing reserve quality wines is easily explained in this context.

We begin with the yields in Napa that range upwards from 2300 bottles per acre – based on what

in Napa are low grape yields of 5000 pounds per acre. (Yields can be double this amount.) High

quality “reserve” wines typically sell at a significant premium over “varietal” or “district” wines

and in many cases are sold only through the winery’s store on site. As one Napa vineyard

manager told the senior author in an interview “we can sell every drop of reserve wine in our

store.” The retail price for reserve wine is in the $35 range - and up. The varietal or district wine

sells for $10-12 or less at retail or half that (or less) at wholesale. Since the finest reserve wines

are sold on the estate – i.e. no middle man is paid to wholesale the wine, and there are almost no

transportation fees, profits are high.

The difference per bottle between reserve quality grapes and others to the winery can be seen to

be in the range of $25 to $30 per bottle – or a minimum of $57,500 per acre. The economics of

the GIS/RS work becomes very clear. With a large vineyard of 800 acres, a 5% increase in

reserve quality grapes turns into an extra $2.3 million profit. Even for a smaller vineyard of 30 to

40 acres, the additional income that flows to the bottom line can easily be well over $100,000.

For a service that costs in the vicinity of $8-10 per acre for one image per year at veraison (the

stage in the ripening process of grapes: the relatively short period during which the firm, green

berries begin to soften and change colour), the economics are clear in a region where there is the

potential to both produce and sell reserve quality wines. The RS/GIS work is a bargain. $400 can

lead to additional profit in excess of $100,000.

Of significant interest in terms of commercial application is that the areas of each vineyard that

produce reserve wines are not exactly the same each year, as is the fact that the imagery is often

used to uncover other vineyard management problems that are manifested both at one time and

over time. These management applications, along with some examples, are discussed below.

MANAGEMENT APPLICATIONS

It is primarily disease monitoring and harvest planning that have been detailed in the literature on

remote sensing/GIS and viticulture cited here. While management applications have been

mentioned, they have usually been considered almost in passing. In fact, remote sensing when

combined with GIS has proven to be useful for a range of vineyard management issues. These

tend not to be as well documented for two primary reasons: those doing the work are “too busy

using the technology to write about it” or the work is considered to be giving the company a

competitive advantage and those involved do not wish to give up that advantage. As noted below, this can cause problems in commercialization. Here we review some of the many applications we

have uncovered in interviews conducted in the Napa Valley, the Niagara Region of Ontario, and

New Zealand over the past two years.

The foregoing discussion suggests the need for an on-going and consistent monitoring year over

year. The consistency of the data provided (and data provider) is important. Getting the

acquisition date right is an issue – it has to be late enough to see stress, but at the same time be

consistent in time of season. Most users in Napa get one image per year at between one and two

meters resolution, although some do obtain multiple flights. Some acquire data at bud-break as

well as veraison. Mid-spring imagery shows the vigour of the cover crop and where there was too

much water. Too much moisture is a problem – often solved by planting a cover crop that will

absorb it or by adding sub-surface drainage.

The monitoring over time (year to year) becomes valuable as changes and/or consistent patterns

are seen from one year to the next. Where the vineyard is part of a larger corporate group the

imagery and maps showing replanting information, re-grafting, wine quality maps, NDVI, and

year-over-year changes are useful in securing support for replanting older vineyards, investments

in irrigation, or other capital projects that must be approved by a management committee not

located on site. The GIS and its outputs can also be used for forecasting for everything from

marketing expenses to when old vines will be pulled out and what will be planted. Here the old

adage “a picture is worth a thousand words” holds true. The image is used as a “report card”

showing if the investments such as irrigation retrofits achieved the desired results.

One large vineyard identified a number of routine applications for the same NDVI data set. In

high vigour crop growth areas and with location from GPS they assess where they should plant a

cover crop to lower or slow the vine growth since it is better in some cases to hold the vines under

a certain degree of stress.

Vineyard managers like to see stress on vines at appropriate times of the year to arrest vegetative

growth and turn the vines' efforts to reproductive growth. This isn't to produce more grapes.

Vineyards are unique in agriculture in that we are not trying to achieve maximum growth as in a

grass seed farmer or corn farmer. Instead the goal of a vineyard manager is “balanced growth”.

Excessive vegetative growth can decrease crop, but more importantly it increases undesirable

flavor characteristics in the grapes. These flavors are commonly referred to “herbal” or green

pepper flavors. Technically these flavors result from a group of chemicals called pyrazines.

Managers also plan pre-pruning in vigorous areas to cut the canes back 5 or 6 inches. They can

also do an analysis of stem water potential and soil sampling based on the NDVI results. For

example they use the NDVI to determine where they should take neutron probe measurements

(for soil moisture measurement). In one case, they found an area where the vines were stressed

for several years. It was found that there was a hard clay pan preventing the roots from growing

deeper. They did a deep disc 18 inches from the vines to allow the roots to go deeper and the

vigor returned. They also use the data to help estimate how much seed for cover crops to order.

“All sorts of measures can be done quickly and easily” said the Chief Horticulturalist. Of course

in the case of this vineyard the NDVI and other data in the GIS are used to help the wine maker

decide where to sample and that in turn determines which grapes are harvested when and for what

quality.

Vineyards have historically been farmed on a block by block basis. A block is defined as a

contiguous planting of vines uniform in variety, rootstock and, if irrigated, irrigated uniformly.

Using NDVI, vineyard managers can dissect a vineyard block, and come up with strategies to

manage different parts of the block appropriate to the vines needs with the goal of creating

uniform vine growth throughout the vineyard. Uniform vine growth throughout a block is highly

desired by vineyard managers because with it, the block is more easily be managed and tuned to

wineries specifications. In order to achieve uniformity a vineyard manager may look at fertility of

the vine and soil in different vigor zones. Also, they may look at the vine-soil water relationship

by using different tools such as leaf or stem water potential, soil moisture as measured with a

neutron probe or c-probe. Further, soil physical characteristics and the impacts of past

management decisions can be assessed. To remedy variation in a vineyard block the vineyard

manager has a vast tool set. Modifying the irrigation systems to irrigate weak vines more may be

as simple as adding additional water emitters or adding second irrigation lines. Differential

disking of the cover crop can remove the competition for water in the weak zones while allowing

the cover crop to compete with the stronger vines. Some vineyard managers are using GPS on

their tractors that show the operator when they are entering a different vigor zone. There are

many other tools only limited by the creativity and budget limitations of the vineyard manager.

Another group found that different slopes and soil characteristics tended to lead to wines resulting

being reserve, grand cru and premier cru. Slope and aspect has also been linked in Napa and

Niagara to frost pockets and winter kill. Another vineyard manager noted that there is some

relationship to evapo-transpiration and the water regime within the plots. The NDVI is also tied to

pruning weight ratios which is used as a stand-in for leaf area. The balance of the amount of crop

to pruning weight is important, as noted above. “Most people on the fine wine side think that the

information is worth it and are willing to pay for it,” said the manager. Another interesting

monitoring application is the overview of neighbouring vineyards to look for evidence of stress

that may “leap the fence” and cause problems down the road – or across it. Vine mealy bug is a

notable current example of this. It transmits the leaf roll virus which is highly detrimental to

vineyards. Herbicide damage is another example where someone sprays a herbicide on another

crop next to a vineyard and prevailing winds blow the herbicide onto the vineyard. In Oregon’s

Willamette Valley, where grass seed fields border vineyards, this is common.

4.

Source:

Adding value to the wine business precisely: using precision viticulture technology in Margaret River

Authors:

Tony Proffitt, Bruce Pearse

Presented At:

The following excerpts are from an article which was presented at a workshop, Managing vineyard

variation – precision viticulture, as part of the 12th Australian Wine Industry Technical Conference held in

Melbourne, July 2004. Precision viticulture practitioners from a number of countries presented papers at

the workshop and the proceedings are available at the following web site:

http://awitc.com.au/workshops/Workshop_30B_Proceedings.pdf

Summary

Vineyards and wine companies in the Margaret River region are experimenting with precision viticulture

technologies such as airborne remote sensing and grape yield monitors. The case studies presented show

that these early adopters of the technology are beginning to realize the potential economic benefits of

understanding and working with vineyard variability.

Excerpts:

With the increasing use of a range of information technologies, collectively referred to as

Precision Viticulture (PV), it is becoming increasingly apparent that vineyards vary substantially

in both the quantity and quality of wine grapes being grown. The emergence of global positioning

systems (GPS) allows the traditional measures of vine productivity to be easily linked to specific

locations within the vineyard. Recent advances in observation tools such as grape yield monitors,

airborne optical remote sensing and soil-sensing instrumentation means that spatial data can now

be more easily collected and recorded. These layers of information enable the viticulturist or

vineyard manager to make more informed decisions related to desired productivity outcomes.

This article describes some recent research and commercial uses of these technologies in the

Margaret River region of Western Australia, with an emphasis on the economic benefits of their

application.

Obtaining information on vine parameters across a whole vineyard is both difficult and

expensive. However, vines, like any plants, are likely to integrate the effects of their local

environment (eg. climate, soil properties, and disease, nutrient and water pressures) and express

them through their canopy characteristics (Wiegand and Richardson 1984). Airborne remote

sensing provides a means by which information on vine characteristics such as canopy status can

be easily collected, and, as an emerging technology, has been the subject of recent PV research

(Hall et al. 2002; Dobrowski et al. 2003; Lamb et al. 2004). Typical remotely sensed images

identify relative differences in vine canopy status across the vineyard as opposed to absolute differences, thereby making comparisons between different data-sets difficult.

Such images are now being used in the Margaret River region to separate vineyard blocks into

areas or ‘zones’ of low, medium and high vine-vigour. Similarly, yield maps or ‘surfaces’

generated from data collected by monitors aboard grape harvesters are now being used to separate

vineyard blocks into zones of low, medium and high yield. Once delineated, blocks which have

traditionally been managed uniformly, are now being managed differentially with respect to both

inputs (eg. fertiliser, water, mulch, canopy-management techniques) and outputs (grapes, wine).

At classification, there were sufficient differences in wine quality between the two zones to

allocate the batches to different end products. Wine made from fruit harvested from the northern

zone was allocated to the ‘Classic Dry Red’ brand (retail price approximately $19 per 750ml

bottle), whilst wine made from fruit harvested from the southern zone was allocated to a varietal

Cabernet Sauvignon brand (retail price approximately $30 per 750ml bottle). If the block had

been harvested as a single unit, the resulting wine is likely to have been allocated to the lower

endues product. Assuming that 1t of fruit produces 750L of wine, the gross retail value of

production was approximately $484,500 and $380,400 for the northern and southern zones

respectively. By using PCD imagery and splitting the block into different management zones, the

total gross retail value of production was therefore $864,900 compared to $725,420 if the block

had been harvested as a single unit. For further information refer to Bramley et al. 2003.

5.

Source:

Review. Precision Viticulture. Research topics, challenges and opportunities in site-specific vineyard

management

Authors:

J. Arnó1, J. A. Martínez-Casasnovas, M. Ribes-Dasi and J. R. Rosell

Journal:

Spanish Journal of Agricultural Research 2009 7(4), 779-790

Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)

Available online at www.inia.es/sjar ISSN: 1695-971-X

Abstract

Precision Viticulture (PV) is a concept that is beginning to have an impact on the wine-growing sector. Its

practical implementation is dependent on various technological developments: crop sensors and yield

monitors, local and remote sensors, Global Positioning Systems (GPS), VRA (Variable-Rate Application)

equipment and machinery, Geographic Information Systems (GIS) and systems for data analysis and

interpretation. This paper reviews a number of research lines related to PV. These areas of research have

focused on four very specific fields: 1) quantification and evaluation of within-field variability, 2)

delineation of zones of differential treatment at parcel level, based on the analysis and interpretation of

this variability, 3) development of Variable-Rate Technologies (VRT) and, finally, 4) evaluation of the

opportunities for site-specific vineyard management. Research in these fields should allow winegrowers

and enologists to know and understand why yield variability exists within the same parcel, what the

causes of this variability are, how the yield and its quality are interrelated and, if spatial variability exists,

whether site-specific vineyard management is justifiable on a technical and economic basis.

The application of Precision Agriculture (PA) techniques in viticulture is relatively recent. In

1999, results began to be published from projects initiated in Australia (Bramley and Proffitt,

1999) and USA (Wample et al., 1999) in the wake of the appearance on the market of yield

sensors and monitors. These are installable in grape harvesters and allow more detailed

measurement of within-field variability. As a result, variable-rate application (VRA) of inputs and

selective harvesting at parcel level have become productive strategies which can provide

significant benefits for winegrowers. The most relevant aspects which need to be taken into

consideration include efficient use of inputs, differentiation of various grape qualities at grape

harvest time, yield prediction and greater precision and efficiency of samplings conducted at

parcel level (Bramley, 2001b; Bramley and Lamb, 2003; Martínez-Casasnovas and Bordes,

2005).

There are several reasons to justify the suitability of the vineyard for PA. As grapevines grow in

lines and with a fixed planting distance, the sampling points can be applied to individual vines

which are georeferenceable and, if data collection is carried out year after year, historical series of

important value for crop management can be obtained. In addition, its perennial nature suggests

that yield spatial variation will maintain some behavioral pattern from one year to the next, an

essential characteristic if the aim is to carry out some type of differential action (site-specific

management) within the parcel. The growing interest in questions related to grape quality has

undoubtedly aroused the greatest expectations in the field of PV. Indeed, the possibility of being

able to differentiate between zones of different quality within the same parcel is one of the

priority aims of PV. Precision Viticulture is a concept that is beginning to have an impact on the

wine-growing sector, not only in Australia, Argentina, Chile, South Africa or USA but also in

Spain and other European countries (France and Portugal in particular). The main objective of PV

coincides, in essence, with the generic objectives of PA: the appropriate management of the

inherent variability of crops, an increase in economic benefits and a reduction of environmental

impact (Blackmore, 1999; Sudduth, 1999). Adaptation of the latest scientific and technological

developments, and examination of economic criteria for market competitiveness, have given rise

to more pragmatic and modern approaches as well as to the growing prominence in viticulture of

countries such as Australia, Chile and South Africa (Sotés, 2004). Indeed, much of the leading

research in PV is carried out in these countries.

Precision Agriculture (Viticulture) can be basically described as an example of the conversion of

data into decisions (McBratney and Whelan, 2001).

PA allows treatments to be carried out with variation of the amounts applied within the same

parcel. In this way, fertilizers and pesticides are only used where and when they are necessary and

in the appropriate amounts for each site. With this consideration in mind, it is easy to accept the

idea that PA can bring clear environmental advantages. Limitation (adaptation) of the applied

fertilizer level in accordance with the productive potential (response) of the different zones of a

parcel (with the consequent reduction in contamination due to losses of N) (Bongiovanni and

Lowenberg-Deboer, 2004) and the reduction in the use and spray drift of pesticides (Giles and Downey, 2003), are clear examples of the possible contribution of PA to greater sustainability of

agricultural production processes.

For the grape growers, PV improves the use of productive factors (water, fertilizers, crop

protection products), reducing costs and minimizing the environmental impact. Even the design

and planting of new parcels can be more appropriately planned by examining their spatial

variability. Selective vintage and pricing by product quality are other possibilities offered by PV.

For the winemakers, PV improves the logistics of the winery, based on better programming of the

grape harvest and improved yield forecast. Selective harvesting of the grape, based on criteria of

quality and/or market expectations, is a technique of undoubted interest for the industry. In

experiments conducted in Australia, Bramley et al. (2003, 2005b) managed to divide a parcel into

zones through the use of an aerial photograph taken during the stage of grape véraison [the stage

during which the greatest correlation between the image and the parameters of yield and colour is

obtained (Lamb, 2001)]. From the Plant Cell Density (PCD) index, subsequent analysis of the

image enabled differentiation of two zones of different vigour, but also of different quality. The

zone with the higher PCD index, of greater vigour and yield, produced a wine with an overall

lower quality. The advantage of selective vintage lay, therefore, in the greater economic benefit

obtained when harvesting the two zones and processing the grapes separately.

6.

Source:

Use of Precision Viticulture Tools to Optimize the Harvest of High Quality Grapes

Authors:

Stanley Best, Lorenzo León and Marcelino Claret

Journal:

Information and Technology for Sustainable Fruit and Vegetable Production

FRUTIC 05, 12 – 16 September 2005, Montpellier France

CONCLUSIONS

The NDVI, it is presented like a highly useful variable for the yield and quality estimation in the

vineyards under our study conditions… The NDVI presents the advantages of being an

integrative and robust variable of the physiology of the plant, easily transferable to the Chilean

viticulture sector.

7.

Source:

Canadian small UAV operator, Ontario, Canada’s High Eye Aerial Imaging Company’s Marketing

Literature

Specific Vineyard Applications

An example from a recent study from Australia, describes the financial advantage of using NDVI

imagery to determine a differential harvesting program. Briefly, the study stated by using NDVI

imagery to divide the blocks into high quality and lower quality sections, then harvesting

differentially resulted in an increase of revenue of over 19%! With the cost of the imagery

factored in the return on the imagery cost was 870%.

Problem Identification

Problems causing non-uniformity in a vineyard are quickly recognized and the extent described

with an NDVI image. A plan of field examination can be readily developed and implemented to

determine if the problems are pest, nutritional, water or disease. If the NDVI image is geo

referenced in digital form, you can utilize your with GPS equipment to immediately locate the

required sample areas.

Practice Improvement

A key objective of vineyard management is to improve the return-on-assets through improving

fruit quality (i.e., higher value fruit) while at the same time bringing the vineyard to as close to

uniform as possible.

Sample zones for petiole analysis can be determined from NDVI as petiole pressures match well

with NDVI classes.

o Time period comparisons can describe the progress of changes to bring about uniformity

and to statistically describe uniformity.

o Differences in vegetation growth on NDVIs help design soils analysis plans for existing

and planned vineyards.

o Irrigation sets and block changes are typically the first benefit of NDVI imagery with

either savings in water or increases in water distribution efficiency.

Precision Application

Fertilization and application zones are easily described from NDVI imagery and the vineyard can

be staked for start-stop points or field computers can be carried by applicators with specified GPS

points.

Harvest Planning

While an idealized goal of management is to provide uniform vineyard blocks, the reality is it

takes time, and some blocks will just never be uniform. The winemaker can use an NDVI image,

once sugar and other qualities have been related to color classes by block, to define a harvest

plan. The vineyard can be flagged, staked or otherwise marked to define harvest zones.

Another significant benefit to the winemaker as a result of using NDVI is the ability to easily

view the vineyard on a sub-block basis. This allows the winemaker to create a greater number of

wine lots with greater uniformity in each lot, which in turn allows for more blending and a greater

potential return to the winery.

Properly utilized by the vineyard manager and winemaker, NDVI imagery will:

o Leverage the return on vineyard assets through increased efficiency

o Improve vineyard management protocols

o Improve grape quality

o Increase block uniformity

o Allow the winemaker to view block production and quality at the sub-block level

o Increase efficiency in berry sampling

o Improve harvest design efficiency

o Provide an excellent grower relations tool

o Expand the number of wine lots while improving the quality and uniformity of the lots,

which in turn allows for more blending options and higher potential returns on the

finished product.

How can NDVI help improve grape quality and reduce costs

o Improve grape quality: Find problem areas quicker and start developing uniformity

throughout the vineyard.

o Save money and time: Work more accurately and precisely AND save labor hours!

o Save water: reduced water usage by as much as 60% using NDVI images and moisture

o Save fertilizer: Perform precise inputs with fertilizer, pesticide and cover crops.

o Environmental stewardship: Help protect the environment by reducing inputs.

8.

9.

UAV-IQ Calculated ROI:

With an annual subscription and three standard resolution flyovers, if vineyards save 1% of cost and

increase yield by just 1%, UAV-IQ offers the average sized Napa vineyard an ROI of 396%

ROI Calculation:

Napa Example

· Avg. Napa vineyard operating cost per acre ≈ $3,500/yr

· Average acreage = 340 acres

· Baseline Annual Production Cost = $1,190,000

· Value per ton of grapes: $4,400

· Average tons per acre = 3

· Yield per Acre: 3 tons X $4,400 = $13,200

· Cost of annual WineFlight subscription & 3 flights @ standard resolution = $1,250 + (340

acres X $10 /acre X 3 visits) = $11,450

· Incremental Cost: $11,450/$1,190,000 = 0.96%

· Value of saving 1% of cost: $11,900

· Value of increasing yield 1%: $13,200 X 340 acres X 1% = $44,880

· Value to vineyard: $11,900 + $44,880 = $56,780

ROI: $56,780 – $11,450 = $ 45,330 or 396%