canopy management


viticulture Viticulture (from the Latin word for ''vine'') or winegrowing (wine growing) is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of ''Vitis vinifera'', the common grape vine, rang ...

, the
canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapevine Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...
of a
grapevine ''Vitis'' (grapevines) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern hemisphere. It is economically important as the source of grapes, b ...

includes the parts of the vine visible aboveground - the trunk,
cordon Cordon may refer to: Basic meanings * Cordon (fashion), a cord (sewing) or braid used as a fastening or ornament * Cordon (plant), the descriptive term for a particular style of pruning woody plants * a strip of clay added around the outside of a ...

stem Stem or STEM may refer to: Biology * Plant stem '' has lost its leaves, but is producing adventitious roots from the nodes. A stem is one of two main structural axes of a vascular plant, the other being the root In vascular plants, the roo ...

leaves A leaf (plural leaves) is the principal lateral appendage of the vascular plant Vascular plants (from Latin ''vasculum'': duct), also known as Tracheophyta (the tracheophytes , from Greek τραχεῖα ἀρτηρία ''trācheia artē ...

flowers A flower, sometimes known as a bloom or blossom Cherry blossoms in Paris in full bloom. In botany, blossoms are the flowers of stone fruit fruit tree, trees (genus ''Prunus'') and of some other plants with a similar appearance that flower prof ...

, and
fruit In botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the ...

. The canopy plays a key role in light energy capture via
photosynthesis Photosynthesis is a process used by plants and other organisms to into that, through , can later be released to fuel the organism's activities. Some of this chemical energy is stored in molecules, such as s and es, which are synthesized fro ...

, water use as regulated by
transpiration in a tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as a tomato plant. The species originated in western South America South America is a continent entirely in the Western Hemisphere ...

, and
microclimate A microclimate (or micro-climate) is a local set of atmosphere of Earth, atmospheric conditions that differ from those in the surrounding areas, often with a slight difference but sometimes with a substantial one. The term may refer to areas as s ...
of ripening grapes.
Canopy management In viticulture Viticulture (from the Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through th ...
is an important aspect of viticulture due to its effect on grape
yield Yield may refer to: Measures of output/function Computer science * Yield (multithreading) is an action that occurs in a computer program during multithreading * See generator (computer programming) Physics/chemistry * Yield (chemistry), the amou ...
s, quality, vigor, and the prevention of grape diseases. Various viticulture problems, such as uneven grape ripening, sunburn, and frost damage, can be addressed by skillful canopy management.Weiss, S.B., D.C. Luth, and B. Guerra. 2003. Potential solar radiation in a VSP trellis at 38°N latitude. ''Practical Winery and Vineyard'' 25:16-27. In addition to pruning and leaf trim, the canopy is often vine training, trained on trellis (architecture), trellis systems to guide its growth and assist in access for ongoing management and harvest.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 134-135 Oxford University Press 2006


The vine is the main part of the grapevine, extending from the root system in the ground up to the cordons, or arms, of the vine. When the grape is young the trunk is very pliable and must be supported by stakes as part of a vine training system. The height of the trunk varies depending on grape variety and the type of trellis system being used and can range from 4 inches (10 cm) to 30 feet (10 m). During winter dormancy, the trunk can be vulnerable to extreme freezing conditions and will be sometimes buried and insulated with soil to protect it.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 714 Oxford University Press 2006 The trunk is composed of sleeves of conductive tissue (biology), tissue, most notably the phloem and xylem. The outside Bark (botany), bark of the vine contains the phloem tissues which transports sap, enriched by sugars and other molecules, from the leaves to the rest of the vine. During the annual growth cycle of the grapevine, the vine will start to store carbohydrate energy in the wood part of the trunk and roots. The downward passage of phloem sap to the roots and this storing process can be interrupted by the viticultural practice of "girdling" or cincturing the vine. This process can improve fruit set by forcing the vine to direct most of its energy towards developing the grape clusters. The xylem is the woody tissue on the inside of the trunk that moves sap, enriched with water, minerals and other compounds, up from the roots to the leaves.


The cordon, or "arms", of the grapevine extend from the trunk and are the part where additional arms and eventually leaves and grape clusters extend. The cordons are usually trained along wires as part of a trellis system. This training usually fixes the cordon into a permanent position, such as horizontal extending from the trunk in opposite directions.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 199 Oxford University Press 2006


The terms stem, stalks and shoots are sometimes used interchangeably but viticulturalists generally make some differentiation. The stem of the grapevine item, extending from cordon, is considered the shoot and this part is most often pruned in the process of "shoot thinning" to control grape yields. The stalk extending out to hold the grape cluster is known as the bunchstem while the stem of the individual grape berry is the pedicel (botany), pedicel.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 663 Oxford University Press 2006 The shoot of the vine develops from new buds located on the cordon and grow to include the leaves, tendrils and eventually grape clusters. Shoots first begin to appear in spring, following bud break, accelerating growth till the flowering stage and usually slowly by the time that the vine begins veraison. During the stage of veraison (typically mid to late summer), the shoot starts to harden and change color from green to brown.


The shoot is ripening at this point and becomes known as a "cane." In wintertime, the canes of the grapevine are usually completely cut off with the amount and weight of the cane being used to gauge the amount of pruning and canopy management that will be needed for the upcoming year. The "tip" of the shoot is the small (0.4 in/1 cm) part of the shoot furthermost from the vine. Viticulturalist use the growth of this tip as an indication of vine vigor because the tip competes with the grape clusters for resources from the vine. Ideally, shoot growth should come to a stop around the time of veraison; a vine that continues growing the shoots will stand the chance of less fully developed grape clusters.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 627-628 Oxford University Press 2006


A grapevine's leaves are the most visible part of the canopy and also one of the most important. It is through the leaves that the vital physiological process of
photosynthesis Photosynthesis is a process used by plants and other organisms to into that, through , can later be released to fuel the organism's activities. Some of this chemical energy is stored in molecules, such as s and es, which are synthesized fro ...

takes places which creates the carbohydrates that the vine needs to grow and process grape clusters. The size of the leaves vary due to grape varieties with varieties like Merlot having very large leaves and Gewürztraminer noted for having small leaves. The typical size is normally comparable to that of a human hand. In addition to size, there are many of other unique characteristics to the leaves that ampelographers use for plant identification. The size and shape of the leaf's Sinus (botany), sinus (the opening space where the Leaf#Divisions of the lamina (blade), blade of the leaf connects to the Petiole (botany), petiole), the shape of the "teeth" along the outer edge, the arrangement of the five Lobe (anatomy), lobes or projecting parts and the angle and length of the Leaf#Veins, veins can all assist in identifying the grapevine.J. Robinson (ed) ''"The Oxford Companion to Wine"'' Third Edition pg 396-397 Oxford University Press 2006 The color of the leaf can be an indication of the health and nutrition of the vine. Chlorophyll in the leaf gives it a natural greenish color. Prior to the winter dormancy, the vine will stop being photosynthetically active which will contribute to a natural break down of chlorophyll and changing of color. However, deficiency in nitrogen or sulfur could cause the vine to turn prematurely (such as before harvest (wine), harvest) yellow. The appearance of reddish spots of brown "dead zones" could be the sign of a viral infection (such as the leafroll virus) or contamination through the use of herbicides. Viticulturalist will use a leaf to fruit ratio as a guideline in determining a vine's ability to fully ripen grapes. Quite different from the consideration of yields, the balance of leaf cover (needed for photosynthesis) and proportion of fruit (judged by weight rather than number of clusters) could have the most substantial effect on the quality of the grape for winemaking. Pioneered by viticulturalist Richard Smart (viticulturalist), Richard Smart, the idea of maintaining a "balanced vine" is to have just enough leaf cover for the plant to produce the energy needed to ripen the grape without having too much photosynthetic activity to where the vines has a surplus of energy and continues growing more shoots. Additionally, leaves provide shade to the grape clusters which be beneficial in protecting the clusters from the harshness of heat stress ("sunburn") but excessive shade can also decrease the development of sugars, anthocyanins and other natural phenol in grape, phenolics and other important compounds in the grape. Many vineyards employ the practice of leaf removal throughout the growing season to try to maintain optimal leaf coverage.

See also

* Canopy (biology)


{{DEFAULTSORT:Canopy (Grape) Viticulture Wine terminology