The Determinants Of Grape Regions





Climate, soil, site, the surface features of the land, insects, fungi

and commercial geography are the chief factors that determine regions

for money-making in grape-growing. This has been made plain in the

foregoing discussion of grape regions, but the several factors must be

taken up in greater detail. To bound the regions is of less importance

than to understand why they exist--less needful to remember, more

needful to understand. From what has been said, the reader has no

doubt already concluded that successful grape-growing is in largest

measure due to kindliness in climate.





Climate



Under the assumption, then, that climate, of all factors, is chief in

playing providence to the grape, let us examine somewhat critically

the relations of climate to grape-growing. When analyzed, the

essentials of climate, as it governs grape-growing, are found to be

six: first, length of season; second, seasonal sum of heat; third,

amount of humidity in summer weather; fourth, dates of spring and

autumn frosts; fifth, winter temperature; sixth, air currents.



Length of season.



To reach true perfection, each grape variety has a length of season of

its own. With each, if it is grown in too low a latitude, the vine is

uninterrupted in growth; its leaves tend to become evergreen; and not

infrequently it produces at the same time blossoms, green fruits and

ripe fruits. This is, of course, the extreme to which grapes pass in

the far South. Again, many northern varieties fail where southern

grapes succeed because the fruits pass too rapidly from maturity to

decay. On the other hand, very often southern grapes are hardy in vine

in the North, but the season is not sufficiently long for the fruit to

mature and to acquire sufficient sugar to give them good keeping

quality, properly to pass through vinous fermentation, or even to make

a good unfermented grape-juice. In the uneven topography of this

continent, it is not possible to state the range in latitude in which

grapes can be cultivated to advantage, for latitude is often set aside

by altitude. Thus, isothermal lines, or lines of equal temperature,

are much curved in America and do not at all coincide with the

parallels of latitude.



Other factors, of course, than length of season enter into the

ripening of grapes. The daily range in temperature, not always

dependent on latitude, affects ripening. Cool nights may offset warm

days and delay ripening. Certainly rains, fogs and humid air delay

maturity. The bottom heat of loose, warm, dry gravelly or stony soils

hastens maturity. Sunshine secured by a sunny aspect or shelter

hastens maturity.



The seasonal sum of heat.



Successful cultivation of the grape depends on a sufficient amount of

heat during the summer season. The theory is that buds of the grape

commence to start when the mean daily temperature reaches a certain

height, and that the sum of the mean daily temperature must reach a

certain amount before grapes ripen. Manifestly, this sum must vary

much with different varieties, low for the earliest sorts, high for

the latest. There have been many observations as to the temperatures

at which buds of the grape start growth, so that it is now known that

the temperature varies in accordance with locality and degree of

maturity. Roughly speaking, grape buds start at temperatures from 50 deg.

to 60 deg. F. The seasonal sum of heat for ripening is probably 1600 to

2400 units. A variety ought not to be planted, therefore, in a region

in which the average seasonal sum of heat is not sufficiently high.

The seasonal sum of heat can be determined for a locality from data

published by the United States Weather Bureau; and by comparing with

the sum of heat units in localities where a variety is known to

thrive, the grape-grower can determine whether there is sufficient

heat for any particular variety.



The grape seldom suffers from hot weather in a grape region. The fruit

is sometimes scalded in the full blaze of a hot sun, but the ample

foliage of the vine usually furnishes protection against a burning

sun. At maturing time, the heat of an unclouded sun, if the air

circulates freely, insures a finely finished product. Deep planting

helps to offset the harmful influences of warm climates.



Humidity of summer weather.



The grape is very sensitive to moisture conditions, and grows best in

regions where the summer rainfall is comparatively light. A damp and

cloudy summer brings disaster to the vineyard in several ways; as

small growth of vine, small set of fruit, a crop of poor quality, and

the development of the several fungous diseases. Although the grape

stands drought, a superfluity of moisture in the soil may do little

harm, as is shown in irrigated vineyards, but a humid air is fatal to

success especially if the air is both warm and wet. Moist weather

during the time of maturity is particularly disastrous to the grape,

as are frequent fogs. Cold wet weather in blooming time is the

grape-grower's vernal bane, since it most effectually prevents the

setting of fruit. It may be laid down as a rule that the grape lives

by sunlight, warmth and air--it often thrives on the desert's edge.

These considerations make it manifest that the monthly and seasonal

means of precipitation must be considered in selecting a locality to

grow grapes.



Spring and autumn frosts.



The average date at which the last killing frost occurs in the spring

often determines the limit in latitude at which the grape can be

grown. Even in the most favored grape region of the continent, killing

frosts occasionally destroy the grape crop, and there are few seasons

in which frost does not take some toll. Thus on May 7, 1916, frost all

but ruined the crop of wine- and table-grapes in the great grape

region of northern California where frosts are seldom expected in May.

Little or nothing can be done to protect grapes from frost. Windbreaks

as often favor the frost as the vine, and smudging or heating the

vineyards is too expensive to be practical. In growing grapes,

therefore, the commonly recognized precaution of selecting a site

near water, on slopes or in a warm thermal belt must be exercised.



The limits of grape culture are also determined by early autumn

frosts. The grape stands two or three degrees of frost, but anything

lower usually destroys the crop. Here, again, the only precaution is

to take pains in selecting the site.



The use of weather data and dates of life events of the grape.



These considerations of length of season, humidity and spring and fall

frosts make it plain that the grape-grower must synchronize these

phases of climate with the life events of the grape. In particular, he

must study weather data in relation to the blooming and ripening of

grapes. Usually, the necessary weather data may be secured from the

nearest local weather bureau, while the date of blooming and ripening

may be obtained from the state experiment stations in the states where

the grape is an important crop.



Winter temperature.



Varieties of native grapes are seldom injured in America by

winter-killing, since they are usually planted in climates in which

wild grapes withstand winter conditions. Native varieties follow the

rule that plant and climate are truly congenial in regions in which

the plant thrives without the aid of man. A few varieties of native

grapes fare badly in the winter's cold of northern grape regions, and

the tender Vinifera vine is at the mercy of the winter wherever the

mercury goes below zero. In cold climates, therefore, care must be

exercised in selecting hardy varieties and in following careful

cultural methods with the tender sorts. If other climatic conditions

are favorable, however, winter-killing is not an unsurmountable

difficulty, since the grape is easily protected from cold, so easily

that the tender Viniferas may be grown in the cold North with winter

protection.



Air currents.



Currents of air are of but local importance in growing tree-fruits,

but are of general and vital importance in growing the grape. The

direction, force and frequency of prevailing winds are often

controlling factors in the suppression of fungous diseases of the

grape, and the presence of fungi often means success or failure in

regions in which the grape is planted. Winds are beneficial, too, when

they bring warm air or dry air, and when they keep frosty air in

motion. The air must move in all grape regions, whether from canon,

mountain, lake or sea. Sunlight, warmth, and air in motion are life to

the grape. Sometimes winds may be detrimental; as when too cold, too

blustering, or when they bring hail, the latter being about the most

disastrous of all natural calamities. Windbreaks are of small value

and are often worse than useless. Having planted his vineyard, the

grape-grower must take the winds as they blow.





Soils for grapes



A prime requisite for a vineyard being earth in which vines will grow,

successful grape-growing is eminently dependent on the selection of

soil. Many mistakes are made in the great grape regions in planting on

unsuitable soils, the planter going on the assumption that any soil in

a grape region should be good enough for the grape. But the crust of

the earth in grape regions is not all grape soil. In New York, for

example, much of the land in the three grape regions is better fitted

for producing crops for the mason or road-mender than for the

grape-grower. Other soils in these regions are fit for vineyards only

when tiled, and tiling does not make all wet land fit for tilling.

Heavy, clammy clays, light sands, soils parched with thirst, thin or

hungry soils--on all of these the grower may plant but will seldom

harvest.



The ideal soil.



Grapes may be well grown in a wide range of soils if the land is well

drained, open to air and if it holds heat. But without these

essentials, whatever the soil, all subsequent treatment fails to

produce a good vineyard. Generally speaking, the grape grows best in a

light, free-working, gravelly loam, but there are many good vineyards

in gravelly or stony clays, gravel or stone to furnish drainage, let

in the air and to hold heat. Contrary to general belief, the grape

seldom thrives in very sandy soils unless there is a fair admixture of

clay, considerable decomposing vegetable matter and a clay subsoil.

The latter, however, must not come too close to the surface. Some of

the best vineyard lands in the country are very stony, the stones

hindering only in making the land difficult to till. Nearly all grapes

require a friable soil, compactness being a serious defect. Virgil,

writing in Christ's time, gave good advice as to soil for the vine:



"A free loose earth is what the vines demand,

Where wind and frost have help'd the lab'rer's hand,

And sturdy peasants deep have stirr'd the land."



Cold, churlish, sticky or clammy clays are never to the liking of the

grape.



Great fertility is not necessary in grape lands. Indeed, the grape is

conspicuous among cultivated plants for ability to nourish itself

where the food supply is scant. Soils naturally too rich produce an

overgrowth of vine, the season's wood does not mature, the crop does

not set, and the grapes lack sugar, size, color and flavor. Good

physical condition and warmth in a well-watered, well-aired soil

enable the grape to search far and wide for its food.



Drainage.



No cultivated grape endures a wet soil; all demand drainage. A few

sorts may thrive for a time in moist, heavy land, but more often they

do not live though they may linger. The water-table should be at least

two feet from the surface. If by chance this comes naturally, so much

the better, but otherwise the land must be tile-drained. Sloping land

is by no means always well drained, many hillsides having a subsoil so

impervious or so retentive of moisture that under-drainage is a

necessity. The texture of the land is usually improved so greatly by

good drainage that the grower has little need to rely on the clemency

of the season in carrying on vineyard cultivation in well-drained

land.



Soil adaptations.



In the refinement of viticulture, grape-growers find that particular

varieties grow best in a particular soil, the likes and dislikes being

determined only by trial, for the peculiarities which adapt a soil to

a variety are not analyzable. Some varieties, on the other hand, the

Concord being a good example, grow fruitfully in a great variety of

soils. Each of the several species with their varieties has quite

distinct adaptations to soils. This is taken advantage of in planting

varieties on uncongenial soils after they have been grafted on a vine

which finds itself at home in the particular soil. Much has been

accomplished in growing varieties on uncongenial soils by consorting

them with other stocks, an operation which has brought forth volumes

of discussion as to the adaptabilities of cions to stocks and stocks

to soils, subjects to receive attention on a later page.





Insects and fungi



The profitable grape regions of the country have all been established

in regions comparatively free from grape insects and fungi. If pests

came later in considerable numbers, the industry, in the old days,

perished. Here and there in the agricultural regions of the country

may be found a sorry company of halt and maimed vines, remnants of

once flourishing vineyards, brought to their miserable condition by

some scourge of insects or fungi. The advent of spraying and of better

knowledge of the habits of the pests has greatly lessened the

importance of parasites as a factor in determining the value of a

region for grape-growing; but even in the light of the new knowledge,

it is not wise to go against Nature in regions where pests are

strongly intrenched.





Commercial factors



The dominant factors that lead to the planting of large areas to any

one fruit are often economic ones; as transportation, markets, labor,

facilities for making by-products, and opportunity to join in buying

and selling organizations. All of these factors play an important part

in determining the bounds of grape regions, but a lesser part than in

the establishment of large areas of other fruits, for the reason that

the grape is so largely grown for raisins, wine, champagne and

grape-juice, products condensed in form, made with little labor,

easily transported, which keep long and find ready market at any time.

Again, where natural conditions are favorable for grape-growing, the

crop comes almost as a gift from Nature; whereas, if the grower must

breast the blows of unfavorable natural circumstances, no matter how

favorable the economic factors may be, the vineyard is seldom

profitable. Natural factors, therefore, outweigh economic ones in

grape-growing, but the latter must be considered in seeking a site for

a vineyard, a task discussed under several heads to follow.



Accessibility to markets.



Markets ought to be accessible in commercial grape-growing. A location

in which there is a good local market, and at the same time ample

facilities for shipping to distant markets, is desirable. If there

are also opportunities to dispose of any surplus to makers of raisins,

wine or grape-juice, the grower has well-nigh attained the ideal.

Further to be desired are good roads, short hauls, quick

transportation, reasonable freight rates, refrigerator service and

cooeperative agencies. The more of these advantages a grower has at his

disposal, the less likely he is to fail in commercial competition.



General versus local markets.



The grower must be reminded rather than informed that he must decide

in locating his vineyard whether he will grow for distant markets, for

manufacturing into grape products, or for local markets. Determination

to grow grapes once made, subsequent procedure at every step depends

on the disposition to be made of the product. Summarized, the

differences in growing grapes for the two markets are: For the general

market: the acreage should be large; the market may be distant; the

varieties few; the cost of production low; sales large and prices low;

the dealings are with middlemen; and extensive culture is practiced.

For the local market: the acreage may be small; the market must be

near and prices must be high; the sales are direct to the consumer;

there must be succession in ripening; and intensive culture is

practiced. For the general market, the vineyard is the unit; for the

local market, the variety should be the unit. In this discussion,

however, "large acreage" and "extensive culture" set against "small

acreage" and "intensive culture" may mislead. This is a case in which

a large endeavor may be a small endeavor, and a small endeavor a large

one; or, in which it may be well to take the advice of Virgil, who

advised Roman vineyardists, "Praise great estates; farm a small one."



The grape-growing of the times tends more and more to growing for

general markets. The grower plants to skim a comparatively small

return from a large area. This division of grape-growing is now well

developed in America. Intensive grape-growing for local markets is not

well developed. There are, however, many opportunities in America for

easy triumphs in fruit-growing in the planting of vineyards for local

markets. No other fruit responds to fine art in culture so well as the

grape. Given choicely good varieties and a finely finished product,

and the grower may have almost what he desires for the produce of his

skill. With the grape, too, palm of merit goes with skill in culture;

among all who grow plants, only the florist can rival the

viticulturist in guiding the development of a plant to a special end.

In cultivating, fertilizing, training, grafting, pruning, spraying, in

every cultural operation, the grape-grower has opportunities to sell

his skill not given in so high degree to the grower of other fruits.



Labor.



A great advantage in the congregation of vineyardists in grape regions

is found when labor must be obtained. Skilled labor is required to

cultivate the vine, and such labor can be freely secured only in

centers of viticulture. Grape-growing is a specialists' business, and

it takes more than a day or a season to make a vine-dresser out of a

farmer, gardener or an orchardist. Expert labor is most easily

obtained and is of best quality where grapes abound. Common labor must

be somewhat abundant, also, in good vineyard locations, for such rush

tasks as tying and picking. In these two operations, women, children

or other unskilled labor may be employed to advantage. The grape

harvest must often be hurried, and to keep it in full swing a near-by

city from which to draw pickers is a great asset.



Vineyard sites.



Within a grape region, the site is important in determining where to

plant. The site is the local position of the vineyard. Sites cannot

be standardized, and therefore no two are alike. The cardinal natural

factors to be secured in a site are warmth, sun, air and freedom from

frost. These factors have been discussed in a general way under the

climate of grape regions, but one needs to particularize a little more

closely to ascertain how they affect individual vineyards. Warmth,

sun, air and frostlessness are best secured by proximity to water,

high land and proper exposure.



Proximity to water.



The favorable influences of water are well illustrated in the grape

regions of New York, Pennsylvania, Ohio and Canada. All of the grape

districts in these regions are bounded on one or more sides by water.

The equalizing effects of large bodies of water on temperature, warmer

winter and cooler summer, are so well known as scarcely to need

comment. Hardly less important than the effects of water on

temperature are the off-shore breezes of night and the in-shore

breezes of day which blow on large bodies of water. These keep the air

of the vineyard in constant motion and so prevent frosts in spring and

autumn, and also dry foliage and fruit so that spores of fungi have

difficulty in finding foothold. But if water brings fogs, dews and

humidity, as does the Pacific, grapes must be planted inland;

otherwise leaf, bloom and fruit are born in the blight of fungi. The

benign influences of water are felt in the eastern grape regions at

distances of one to four miles, seldom farther. These narrow belts

about the eastern waters are bounded on the landward side by high

bluffs over which many showers fail to pass and which protect the

belts below from heavy dews. Where the background of bluffs in these

regions sinks to level land, vineyards cease.



Vineyards are usually some distance above the water, the range in

altitude running from fifty to five hundred feet. Where the altitude

is much higher, immunity to frosts and winter freezing ceases, for

the reason that the atmosphere is rarer and drier so that heat

radiates rapidly from the land. As the height increases, also, the

revels of the wind play havoc with the vines. Yet, one is often

surprised to find good vineyards at the level of the lakes or, on the

other hand, crowning high hills. Altitude in grape-growing must,

therefore, be determined by experiment. We know very little of the

formation of the thermal belts on high land so favorable to the grape.



The lay of the land.



We associate the grape with rugged land; as the vines on the banks of

the Rhine, the rolling lands of Burgundy, the slopes of Vesuvius and

Olympus, the high hills of Madeira, the cloud-capped mountains of

Teneriffe, mountain slopes in California and the escarpments of grape

regions in eastern America. These examples prove how well adapted

rolling lands, inclined plains and even steep and rocky hillsides are

to the culture of the vine. Virgil long ago wrote, "Bacchus is partial

to broad, sunny hills." Yet rolling lands are not essential to the

culture of the grape, for in Europe and America very good grapes are

grown on unsheltered plains, provided the land has an elevation on one

or more boundaries above the surrounding country. If the conditions of

soil and climate which the grape requires can be found on level land

or moderate slopes, such situations are much better than steep

declivities, since on these the cost of all vineyard operations is

greater and heavy rains erode the soil. The soil on hills, too, is

often scant and niggardly. Level land, however, must not be shut in on

all sides by higher land as untimely frost will often lay waste vines

in such a situation.



Exposures.



The exposure, or the slope of the land toward a point of the compass,

is important in choosing a site for the vineyard, although the value

of particular exposures is often exaggerated. Let it be remembered

that good grapes may be grown in vineyards exposed to any point of the

compass, but that slight advantages may sometimes come, depending on

the particular environment of the plantation, and then solve the

problem according to conditions. The following are theories as to

exposure: A southern exposure is warmer and hence earlier than a

northern, and is, therefore, the best slope for early grapes as well

as for very late ones liable to be caught by frost. Northward and

westward slopes retard the leafing and blooming period, thus often

enabling the grape to escape untimely spring frosts; though to plant

on such slopes may be robbing Peter to pay Paul, as what is gained in

retardation in spring may be lost in the fall with the result that the

vines may be caught by frost and may fail to ripen their crop. Frost

damage is usually greatest on a bold eastern slope, and vines suffer

most in winter freezes on this exposure, since the direct rays of the

rising sun strike the frozen plants so that they are more injured than

otherwise by rapid thawing. In locations near bodies of water, the

best slope is toward the water, regardless of direction. The exposure

may sometimes be selected to advantage with reference to the

prevailing winds.





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