Adaptive viticulture in the Caribbean basin


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Adaptive viticulture in the Caribbean basin
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x, 184 leaves : ill. ; 29 cm.
Watlington-Linares, Francisco
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Viticulture -- Caribbean Area   ( lcsh )
Geography thesis Ph. D
Dissertations, Academic -- Geography -- UF
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non-fiction   ( marcgt )


Statement of Responsibility:
by Francisco Watlington-Linares.
Thesis (Ph. D.)--University of Florida, 1990.
Includes bibliographical references (leaves 163-183)
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Table of Contents
    Title Page
        Page i
        Page ii
        Page iii
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    Table of Contents
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    List of Tables
        Page vii
    List of Figures
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    Chapter 1. Introduction
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    Chapter 2. The geographic context of adaptive viticulture
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    Chapter 3. Adaptive hybridization in Florida: Origins and diffusion
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    Chapter 4. Adaptive pruning in Venezuela: Evolution of a paradigm
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    Chapter 5. Toward adaptive synthesis: Puerto Rico
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    Chapter 6. Conclusion
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    Biographical sketch
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Full Text







Copyright 1990


Francisco Watlington-Linares


I would like to express my appreciation to those who contributed in

some way to make this dissertation a reality.

Foremost is Dr. Cesar Caviedes, whose enlightened understanding made

the project possible, whose enviable breadth of expertise contributed

decisively to it, and whose skilled guidance saw it through. I am

similarly obliged to Dr. Jerald Milanich, whose early recognition and

continuing confidence bolstered my determination through difficult times.

I am especially grateful to Lee Newsom for her solidarity, and

selfless contribution of grape seed measurements which will help lend

credibility to the "Sauer grape theory."

Chapter 2 would not have been possible without the generous

assistance of Dr. John McGrew, perhaps the most knowledgeable American

authority on viticultural history. Dr. McGrew provided access to little-

known documentary sources and contributed useful comments on the first

draft. Others who read early drafts of chapter 2, offering encouragement

and constructive comments, were Dr. Harm de Blij, Editor of National

Geographic Research, and Dr. Max Rives of the Consultative Group on

International Agricultural Research. Dr. Rives work was a major source

of inspiration and documentation.

Chapter 3 was reviewed by Dr. David Rogers, taxonomical authority

on native Florida grapes, and Dr. John Mortensen, viticultural geneticist

of the Leesburg, Florida, Agricultural Research and Education Center.

Their comments and suggestions are much appreciated.

Much of the information for Chapter 4 was obtained through the

cooperation of the "Instituto de la Uva" (Lara), and the "Centro de

Viticultura Tropical" (Zulia). Special thanks are due Pastor Petit,

Guillermo Vargas, Damaso Bautista, Eliezer Tortolero, Francisco Araujo and

Pedro Corzo, among others.

Chapter 5 was brought to a happy conclusion due in good measure to

the timely assistance of Dr. Amador Belardo and Dr. Angel Cruz-Baez of the

University of Puerto Rico.

My sincere appreciation is extended also to Ms. Desired Robinett,

who conscientiously processed the manuscript through the final finishing


At last, I would like to thank Dr. Thomas Matthews, who got me to

follow the course of Ponce de Leon, and to Dr. Gordon Lewis, both former

directors of the Institute of Caribbean Studies of the University of

Puerto Rico. Dr. Lewis was unfailing in his endorsement of this project.

Finally, without the support of my parents at critical junctures

this dissertation would not have come to fruition.



ACKNOWLEDGEMENTS . . . . . . . . . . .

LIST OF TABLES . . . . . . . . . . .

LIST OF FIGURES ........ ......................

ABSTRACT . . . . . . . . . . . . .


1 INTRODUCTION . . . . . . . . .
Notes ........ .....................


State of Knowledge . . . . . . .
Adaptation in Grapes . . . . . .
Adaptation in Viticulture ... ............
Adaptive Insolation Optimization ....
Adaptive Pruning . . . . . .
Adaptive Hybridization .........
Notes ........ .....................

. iii

* . viii

* . ix



The Florida Mission Grapes ...
An Archaeological Clue ......
A Search for "El Dorado" .....
Notes ..... ................


The Beginning ... ............
The Pruning Calendar .......
The Creole Hybrids ........
Notes ..... ................

. . . 30

. . . . . 64
. . . . . 67
. . . . . 90
. . . . . 96



A History of Trials ..... ................. ....100
Adaptive Grape Breeding .... ............... ....128
A Viticultural Prospectus .... .............. ... 143
Notes ........ ........................ ...151

6 CONCLUSION .......... ..................... 156
Notes ........ ........................ ...161

REFERENCES ......... ........................... ....163

BIOGRAPHICAL SKETCH ....... ....................... ....184



Table I Hontoon Grape Seeds, Summary of Comparative
Measurements ...... .................... .... 43

Table 2 Simpson's Grape (Fla. 399) Seeds, Summary
of Comparative Measurements ...... ............ 44

Table 3 Fennell's Grape Seeds, Summary of Comparative
Measurements ...... .................... .... 45

Table 4 Vineyard Area in Venezuela, by State,
1969 and 1975 ...... .................... .... 61

Table 5 Evaluation of Fertility Differences in Grape
Cultivars, by Semester (Merida, Venezuela:
latitude 830'N) ...... .................. ... 80

Table 6 Critical Maxima, Monthly Rainfall: El Tocuyo
(Lara), Venezuela, 1978-1988 ...... ............ 89

Table 7 Puerto Rico: Mean Maximum and Minimum
Temperatures and Range, Selected Periods
and Stations ....... .................... .... 119

Table 8 Enological Characteristics of Valplatinta ... ...... 143

Table 9 Puerto Rico: Mean Monthly Rainfall,
Selected Stations ...... .................. ....145



Figure I Transit of daylength at selected
northern latitudes . . . . . . .

Figure 2 Hontoon Grape seed (vitis x hontunensis)

Figure 3 Semiarid areas of western Venezuela, and
approximate extent of April-June and
September-November tolda (6/8ths cloud cover)

Figure 4 Mean monthly rainfall in El Tocuyo, Lara,
Venezuela ...... ..................

Figure 5 An impressionistic comparison of rainfall and
number of days with tolda (7/8ths cloud cover)
by month in Maracaibo, Zulia, Venezuela . .

Figure 6 Puerto Rico: proposed viticultural regions .

Figure 7 Aibonito: Mean monthly rainfall ......

Figure 8 Isabela: Mean monthly rainfall ..........

Figure 9

Figure 10

Figure 11

Juana Diaz (Fortuna): Mean monthly rainfall

Vieques Island: Mean monthly rainfall . .

Diurnal build up of tolda (cloud cover) in
western Puerto Rico, and approximate relation
to daylength . . . . . . . .

. . 63

. . 88

. . 91

. . 106

. . 146

. . 146

. . 147

. . 147

. . 149


Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy



Francisco Watlington-Linares

December 1990

Chairman: Cesdr Caviedes

Major Department: Geography

This dissertation consists of three inter-related case studies on

the origins and evolution of viticultural adaptation in the Caribbean

tropics and Florida. Although the Old World grapevine (Vitis vinifera L.)

is not a tropical plant, European immigrants have intuitively practiced

adaptive insolation optimization for viticulture in the tropics by seeking

out semiarid areas that are relatively free of cloud cover.

Another adaptive technique, hybridization with native American

forms, began in early Spanish Florida and has evolved into a modern

scientific approach which, nonetheless, has been slow to diffuse to the

tropics. One more important technique, adaptive pruning, seeks to

coordinate grapevine phenology with seasonal changes in weather. It has

become a quasi-paradigmatic approach in Venezuela, but attempts to

transfer the technology elsewhere have been disappointing.

In Puerto Rico both hybrids from Florida and Venezuelan pruning were

uncritically introduced with confusing results. Independently, a more

promising mode of adoption and synthesis of the alternative techniques is

beginning to emerge. Throughout the three case studies--Florida,

Venezuela, and Puerto Rico--it is argued and demonstrated that a

geographical variable, effective daylenth, underlies all of the

traditional empirical techniques of adaptive viticulture, a fact that has

escaped recognition by local and international viticultural research and

extension agencies.


Even the best of our agricultural textbooks are right and
valid only for a given set of circumstances; that they fail to make
this explicit, and so convey an air of general validity, is a most
grievous defect.

How does the soil-yield change with latitude, assuming that
soil is everywhere of the same quality, with the same humus content?
(J. H. von Thunen, 1826/1966: pp. 277-278)

In the Caribbean basin there is need for higher income agri-

industrial crops such as grapes, which do well under permanent minimal

tillage cultivation even on degraded hilly terrain (Olmo, 1979). Grape

growing could provide supplementary income for many families that subsist

in marginal rural situations and depend on irregular low-wage jobs in

urban-centered economies (Lewis and Thiele, 1979).

Traditional adaptational practices in viticulture have been

repeatedly introduced to European settlements of the Caribbean basin along

with Old World grapevines (Vitis vinifera L.). Geo-environmental

latitudinal differences, that will be explained in due course, have

favored the development of alternative approaches to viticultural

adaptation, namely, adaptive hybridization in Florida and adaptive pruning

in Venezuela. The search for locations that optimize exposure to sunlight

(insolation) has been, perhaps, the most universal practice in the search

for optimal locations. The empirical adaptive'techniques evolving in

different areas have not been previously analyzed as a coherent system


much less interpreted in terms of a unifying geographic concept that lends

simplicity to a wider understanding of viticultural adaptation in the


A better understanding of the geographical imperatives that underlie

traditional viticultural technology should go far toward enhancing its

effectiveness. Traditional practices and imported innovations must be

studied and applied collaterally, since as one cultural geographer has put


Traditional techniques have deep roots in the aboriginal and
colonial past. Some of the approaches . have been or could be
applied to modern systems. And in Latin America today many, if not
most, farmers make use of both modern and traditional techniques.
(Denevan, 1980: p. 177)

However, folk technology is much too often underestimated by local

agricultural research and extension agencies, which similarly tend to

disregard the perspectives that "outside" disciplines, such as geography,

can offer to the discussion of cultural adaptation.

Although American cultural geographers from Sauer (1969, 1971) to

de Blij (1981) have written extensively on regional viticultural

traditions, none have undertaken the complex task of evaluating imported

viticultural technology in its adaptation to New World geo-environmental

conditions. There are, nonetheless, relevant antecedents in Kollmorgen's

(1943) model of crop-technology complex diffusion from institutional,

corporate and political "culture islands," and Lewis' (1979) correlation

of introduced grape cultigens and immigrant provenance in 19th century


Kollmorgen addresses pertinently the problem of the

institutionalization in Florida (and other Gulf areas) of maladaptive

agricultural technology developed for northern American and European

geographic conditions. A similar concern has occasionally been expressed

with reference to the tropics (Barringer, 1965; Janzen, 1973; Blaut,


A research problem emerges because in viticulture, as in agriculture

generally, cultivational practices are circumscribed geographically by

their very nature. A cultural success, on the other hand, has a tendency

to spread far beyond its area of origin, the locus of its original

adaptation. This means that adaptive processes, bio-genetical and

cultural, must continuously begin anew as a crop is introduced to new

geographical regions.

The issue that arises is twofold. Cultivated plants must undergo

phylogenetic adaptation, an evolutionary process that takes time, though

not necessarily a very long time. More difficult, perhaps, is the

institutional tendency to enshrine traditional practices and artifacts

(including plants) that buttress cultural continuity. Does scientific

training contribute to adaptive change? Not necessarily, this

researcher's experience concurs with that of other observers. Modern

agricultural science is often strongly paradigmatic, parochial, and

politicized (Janzen, 1973; Busch and Lacy, 1983; Smith, 1990). Its

assumptions, procedures, objectives, achievements and limitations reflect

the biases of structural vested interests and traditions as much as any

other activity or institution.


Agricultural experiment stations in the tropics are no exceptions.

As Janzen pointed out:

Nearly all research in tropical agriculture is highly reductionist,
parochial and discipline oriented.
the plea for technological advance gives the scientific
community a perfect excuse to continue their reductionist and
esoteric approaches. (Janzen, 1973: p. 1212)

Local grassroots development of appropriate techniques obtained through

empirical trial and error may counterbalance a "reductionist" scientism,

whether or not this is a veil for self-serving chauvinism (Blaut, 1977).

For as one anthropologist has geographically observed:

Humans are unlike other animals in that they alone project
culture, in the form of conventional understandings, onto the
physical surroundings and then act on and interact with the cognized
environment. (Marquardt, 1985).

Thus, it has been suggested that scientifically sound practices are

empirically selected in cultural evolution (1), despite initial rejection

or lack of recognition by institutional superstructures that resist

deviations from paradigmatic (i.e., "internationally accepted") standards

(Campbell, 1965).

This dissertation is a broadly-based case study of viticultural

evolution in the Caribbean realm, considered from an "anthropogeographic"

perspective. It pursues a qualitative understanding of the complex

relationship between natural phylogenetic evolution in a crop plant, the

grapevine, and the development of its manipulation for human cultural

purposes under diverse tropical ecological conditions. The geographically

variable physical background in which the interaction takes place implies

that the dynamics of the relationship are adaptive (in specific geo-

environmental locations) and diffusionary (to different geographic


locations). Therefore, in the following chapters adaptation and diffusion

in viticultural geography will be explored in a manner which differs from

the descriptive "geography of viticulture" expounded by de Blij (1981) in

its quest for geographically specific adaptive transformation of

viticultural techniques, and of evolution in grapes as "living artifacts"

of culture (Sauer, 1969).

Actually, C. 0. Sauer insisted that the evolution of crop plants be

studied as the conjunction of both physical geographical environment and

of cultivational traditions. He was also, apparently, the first to

propose a likely continuity of specific grape cultigens from prehistory

to the present, and to suggest that the study of aboriginal grapes might

provide an exemplar of fruit crop evolution for southeastern North


Sauer's passing attention to grapes must be understood in the much

broader context of his interest in the New World's agricultural origins.

He seems to have discerned, before anyone else, that the cultural

evolution of perennial crops requiring long term fixed location would have

accompanied, if not preceded, the development of permanent settlements.

The persistence of orchards would have contributed to reinforce

territorial attachment to desirable sites (Sauer, 1971). His real concern

was to find ways of tracing cultural evolution within what he understood

as its proper geographic context--the continuity of human settlements in

preferred locations.

Sauer's conceptualization of permanent settlement in no way

conflicts with sequent discontinuities that result from destruction and

abandonment, or seasonal occupancy. Sauer understood that the same

favored locations are settled, disputed and resettled for similar

geographic reasons. Long lived, fire resistant orchard plants are likely

to be inherited by the successive occupants of a given site. Over time,

such crops would be modified by natural and cultural processes affecting

evolutionary selection in humanized environments. The human cultural

sequence would, thus, be reflected in the evolutionary sequences in hard

seeded crops such as grapes that leave clues in the archaeological record,

and in behavioral contexts as well, as it is discussed in Chapter 3.

Sauer was prescient that the study of cultural evolution in native

grapes would reveal much about Southeastern agricultural origins. He

implicitly proposed that grapes be examined as artifacts of material

culture, both in historic and prehistoric times, and he summarized his

insight memorably in the following passage:

Cultivated plants are living artifacts of times past,
available where archaeology and written document are wanting, or
making these more explicit. (Sauer, 1969: p. vii)

The present investigation follows a Sauerian methodological strategy

in which an explanatory framework is woven from diverse sources of

knowledge within the guiding coordinates of a historical and cultural

geographical perspective. Within this approach the research problem can

be expressed as follows: Why has viticulture, a modern crop-technology

supported by a sophisticated international research establishment,

remained underdeveloped in the Caribbean tropics, despite a long history

of incipiency? A corollary question that arises is: What are the

geographical barriers, physical and cultural, that have hindered the

diffusion of modern viticulture in the Caribbean and/or curtailed its

adaptation there?

In Chapter 2, the researcher expounds his hypothesis that a

geographical variable, daylength, underlies traditional techniques for

viticultural adaptation, from which the following two distinct regional

approaches have emerged. Chapter 3 proceeds to explore the tradition of

adaptive hybridization which is the dominant approach in Florida. Chapter

4 examines the emergence of adaptive pruning as a paradigmatic tradition

in Venezuela, while Chapter 5 evaluates critically the geographical

"barriers," physical and cultural, that have retarded viticultural

development in Puerto Rico, and articulates the prospects for a "state of

the art" synthesis of adaptive techniques. Finally, Chapter 6 offers

general conclusions that can be drawn from interweaving the preceding

cases into a conceptual tapestry that has wider implications for the

future of this activity.

The sources of information on which this dissertation is based vary

for each of the four main chapters because they constitute separate,

although conceptually interrelated, case studies. All rely to some extent

on the critical analysis of documentary sources. These comprise an

exhaustive and current cross-disciplinary bibliography, accumulated over

many years, and a personal collection of published and unpublished

documents: books, reports, letters and articles on viticulture and

related subjects pertinent to the research subject. The core of this

collection is the researcher's personal file of correspondence (1961-1990)

with leading figures of adaptive grape breeding in the Americas.

Additional sources of information resulted from course work in

anthropology and archaeology at the University of Florida between 1981 and

1984. This provided the philosophical rationale for understanding the


evolution of adaptive viticulture, and also an opportunity for the direct

study of archaeological and living grape seeds and grape vines as

artifacts of material culture. In addition, the researcher was able to

improve his skills in the use of interviewing techniques as research

sources and the recording of oral history.

Taped and untaped interviews with the pioneers of adaptive grape

breeding in Florida, with members of the Florida Grape Growers Association

and the North American Grape Breeders Conference, became important sources

of information on adaptive strategies. In addition, direct observation

of viticultural techniques were made in a number of Florida vineyards and

the native cultivars and wild grapes surveyed in much of the state,

including the extensive collection in the Leesburg Agricultural Research

and Education Center. Grape seeds were obtained from various herbaria

(see Chapter 3) as well as directly from the field.

Comprehensive field work that utilized various of the above

mentioned approaches of information gathering was conducted during two

visits to Venezuela, in April of 1988 (to the Tropical Viticulture

Development Center, near Maracaibo), and in November of 1989 (to the Grape

Institute, near Barquisimeto). Each visit was for a period of a week.

Similar field work has been realized in Puerto Rico, on a continuing

basis, from 1985 to the present.

Years earlier, before engaging in doctoral studies, periodic visits

were made to viticultural research centers in Brazil: in 1967 to the

Agronomic Institute in Campinas (Sao Paulo) and the School of Viticulture

and Enology in Bento Gon~alves (Rio Grande do Sul). Likewise, the

researcher participated in 1971 in the first congress of the Brazilian


Fruit Culture Society, held in Campinas, in which viticulture was an

important component. A charter member, the researcher attended subsequent

congresses in 1973 and 1976. In 1975 he visited the Leesburg and

Homestead ARECs, the Interamerican Institute of Agricultural Sciences in

Turrialba, Costa Rica, site of early tropical grape breeding, and attended

the 33rd Congress of the American Society for Horticultural Science,

Tropical Region, in which he was also active for several years. The

following year at the 34th Congress he delivered a paper which heralded

the present dissertation (Watlington-Linares, 1976b). To conclude, the

researcher's long years of "fruitful" experience as an adaptive grape

breeder and experimental viticulturist in the tropics has given him the

knowledge necessary to integrate his sources of information effectively,

and to elaborate and articulate this dissertation.

The cumulative body of research comprised in this work is "grounded"

in the life experience of its protagonist. Consequently, the "design of

research" is to be understood in terms of the qualitative paradigm (Cook

and Reichardt, 1979). This dissertation is the outcome of a personal

inquiry that began as an avocational involvement with tropical viticulture

in the early 1960s, in Puerto Rico. In pursuit of a dream of independence

on a few acres, this researcher was belatedly caught up in the social and

political turmoil of the times. Isolated from active participation by

personal circumstances, he sought an opportunity to make a meaningful


Breeding grapes for the tropics eventually became a major endeavor

within a "scientific" activism that gave expression to his multifarious

interests and commitment. By the early 1970s these had become inseparable

from his professional livelihood, under an umbrella of his creation, the

"Aquarius Experiment Station." His growing personal research and

experience as a "back to the land" consultant raised questions that

participation in international horticultural congresses and visits to

tropical and subtropical experiment stations throughout the Americas could

not answer.

Discontent with the philosophical and practical mediocrity that

seemed to characterize mainstream horticultural research, forced this

researcher to seek enlightenment through advanced academic studies in

geography. In due course he realized that the lack of geographic

awareness that seemed to permeate applied agricultural science was

compounded by an equally blatant disregard for humanistic (i.e.,

anthropologic) considerations. Again, it was the author's minor field,

anthropology, that provided the qualitative rationale of scientific

research (Cook and Reichardt, 1979), that he opposes to the positivist

paradigm dominating horticulture.

The scope of this dissertation is necessarily circumscribed to a

consideration of the climatic parameters assumed to be critical in the

tropical adaptation of viticulture. Soil, for example, is considered here

only as a secondary factor, in accordance with recent authoritative

opinion (Santibafiez et al., 1986).(2) For analogous reasons, economics

are not extensively considered either. However, adaptation clearly has

a direct bearing on production costs and, therefore, on long term economic




1. Cultural evolution is here defined as the adaptive transformation
of a cultural form, in this case a specific crop-technology complex,
through geo-environmental and cultural factors. It is equivalent
to Sahlins' (1960) "specific evolution," amended to emphasize
natural selection (Stoddart, 1966; Dunnell, 1978) and cultural
selection (Campbell, 1965; De Wet and Harlan, 1975).

2. Winkler (1962) was one of the first to challenge the "proprietary"
European view that assigned decisive qualitative attributes to
particular soil compositions and textures. Winkler conceded that
in northern regions, such as in Germany, slate-stone and shale might
be beneficial by absorbing heat during the day. Similarly,
limestone would offset the high acidity of grapes grown in the
cooler winegrowing areas of France (Ibid.).


State of Knowledqe

In this chapter the working hypothesis of the present dissertation

is elaborated. The research method utilized has been the historical

analysis of adaptive techniques in viticulture recorded from the earliest

to the most recently available documents. On one hand, the survey focuses

on how these relate to environmental conditions, and on the other hand,

to grapevine phenology and physiology. Consequently, the research is both

cross-disciplinary and cross-cultural, as well as historical.

Adaptive viticultural techniques linked to geographic parameters

have been reported in European agricultural treatises of the Classic,

Medieval and Renaissance periods. Exemplary contributions are those of

the Andalusian Spanish agronomists Columella (42/1941), Ibn Al-Awwam

(1200/1802), and Herrera (1513/1970). It has been suggested that

traditional folk technology for grape cultivation was introduced to the

Spanish settlements of the New World in the 16th century, precisely from

Andalusia, along with the Old World grape cultigen Vitis vinifera L.

(Watlington-Linares, 1983).

Adaptive viticulture evolved empirically in various regions of the

Ibero-American tropics and subtropics since the early colonial period.

However, its counterpart in modern middle latitude viticultural technology

has formal antecedents in 19th century European biogeography. In the

United States this is epitomized by the work of De Candolle (1859),

Lippencott (1862) and finally Koppen, who in 1900 summarized his

predecessors' efforts to correlate climatic variation and plant adaptation

(Thornthwaite, 1943), but unlike them had no special interest in grapes.

In the first half of the 20th century, research on viticultural

adaptation in the United States declined and became parochial as the

result of a conjunction of political interests opposed to the expansion

of wine growing (Adams, 1978). Consequently, 19th century "heat

summation" remained a popular adaptational criterion in American

viticulture.(1) The concept was refurbished by Winkler (1938) with

refinements added by others over the years (Branas et al., 1946;

Santibahez et al., 1986).

Poor adaptedness of high latitude grapes in the lower latitudes has

commonly been attributed to lack of winter chilling (Magoon and Dix, 1943;

Mortensen, 1981; Olmo, 1986). However, a chilling requirement is not

mentioned in specialized reviews of climatic factors and grape phenology

(Buttrose, 1974; Alleweldt and Hofacker, 1975; Srinivasan and Mullins,

1981). Nonetheless, the belief that grapevines need periods of cold

weather remains somewhat paradigmatic (sensu Kuhn, 1970) in Caribbean

agricultural extension service lore.

Modern experimental studies on geo-climatic influences in grape

phenology were initiated in the mid-1930s in Germany (Moschkov, 1935;

Hackbarth and Scherz, 1935; Husfeld, 1936) dealing mainly with acclimation

to freezing weather. After World War II the work was resumed in West

Germany (Burckhardt, 1958) and taken up in other countries, including


France (Huglin, 1958), Russia (Grecisnikov, 1958), Italy (Khalil, 1961),

Japan (Kobayashi et al., 1966), and Australia (Antcliff and May, 1961).

The cumulative findings of this accruing body of research point

unequivocally to a geographical variable, latitudinal daylength, as the

principal parameter of viticultural adaptation. Concurrently, ambient

temperature has been qualified as an important complementary factor

(Kobayashi et al., 1967; Kliewer, 1973; Hale and Buttrose, 1974).

The viticultural implications of the latitudinal variation of the

amplitude of seasonal daylength as an adaptive parameter in grapes has not

been widely recognized. Physiological studies have been concerned

primarily with the abstraction termed "photoperiodism" (i.e.,

physiological responses to experimental cycles of light and darkness, in

abeyance of actual geographical conditions), in the controlled, artificial

environment of "growth cabinets" (Buttrose, 1974). Their research design,

interpretation of findings, and extrapolation to the "field" reveals, by

and large, surprising indifference to the geographic context of

Alvim (1964) reviewed the phenological effects of seasonal daylength

variation on perennial crops in the tropics and indicated that slight

seasonal fluctuations in calendar daylength is sufficient for response to

photoperiodicity in latitudes as low as 10 degrees or less. Alvim also

garnered evidence that photo-phenology in tropical fruit and nut crops is

often synchronized with alternating periods of clear skies rather than

with calendar daylength.(2)

Because rainfall in the tropics is essentially convective (Flohn,

1973), rainy periods are normally accompanied by heavy overcast or tolda

of cumulonimbus cloud cover. It has been observed that tolda may

influence daylength responses in many plants, particularly if occurring

at the beginning of day, thereby extending the duration of night-time, the

effective "operand" of photoperiodism (Vince-Prue, 1975). Nonetheless,

over half a century since Garner and Allard first defined photoperiodism

(Ibid.) the lack of an applied integration with actual geographic

daylength is suggested by the questions raised in a current review of the

state of knowledge on photo-phenology.

Under natural conditions the transition to and from darkness is not
abrupt but occurs through a gradually changing intensity of
twilight. At what point does the plant begin to respond to
darkness? Or to light at dawn? Is the effective length of day
influenced by morning or evening clouds? . It has been suggested
that the presence of clouds during twilight and dawn can influence
the photo-periodic response. (Vince-Prue, 1975: 80-81).

Adaptation in Grapes

All grapes are perennial woody vines that respond to seasonal

changes in their native habitats with appropriate physiological

adjustments (Branas, 1974). They tend to stop growing and shed their

leaves in response to shortening daylengths that signal the arrival of a

season sensed as unfavorable: winter in the higher latitudes, estio or

dry season in the "wet-and-dry" tropics (Critchfield, 1974). However,

seasonal vegetative inhibition also promotes conditioning for the fruiting

cycle that ensues with the return of longer days and favorable weather

(Kliewer, 1981). Adaptation in grapes is thus conditioned by the need for

alternating periods of both "favorable" and "unfavorable" daylengths.

Because the onset of critical seasonal changes is generally preceded

by equinoctial daylength, most grapes require days longer than twelve

hours for normal growth and productivity (Buttrose, 1969a; Sugiura et al.,

1975). How much longer for grapes in their native habitat depends on the

particular daylengths that commonly precede critical weather at a specific

latitudinal location and on the time required for appropriate

physiological adjustment.

Grapes native to climatic belts north of the 30th parallel respond

to equinoctial or lesser daylengths by preparing for freezing weather

(Moschkov, 1935). The more northerly forms must be progressively

unresponsive to daylengths not considerably longer than the equinoctial

threshold (Pierquet and Stushnoff, 1978). On the other hand, the

neotropical pan-species V. caribaea D.C. interprets shorter than

equinoctial daylengths as the harbinger of annual drought lasting around

four months (Schwerdtfeger, 1976). Though the range of variation in

daylength duration increases away from the equator, it appears to be

significant at least to latitude 100 or lower (Figure 1), where V.

caribaea is native.(3)

Daylength requirements and related responses for different stages

of the phenological cycle vary geographically between and within grape

species (Hackbarth and Scherz, 1935; Pierquet and Stushnoff, 1978). It

follows that natural selection in grapes favors ecotypical (essentially

latitudinal) adaptation in terms of synchronization of photo-phenology

with local seasonal climates (Rives, 1972). Consequently, adaptation to

a given daylength regime will largely determine 1) the comparative

adaptability of non-native cultivars; 2) the manipulation of phenological

cycles to coincide with tolerable daylengths and seasonal climatology;

14 lat





10 300
Mar- -Apr-May- -Jun-Jul- -Aug- -Sep-Oct- -Nov- -Dec

Figure 1. Transit of daylength at selected northern latitudes.

Source: Drawn by the author from data in the United States Naval
Observatory Air Almanac, 1960.


and, 3) the selection of adapted (i.e. healthy and productive) cultivars

from hybrid progeny.

Adaptation in Viticulture

Viticultural adaptation in the lower latitudes has been achieved

traditionally through empirically developed techniques that implicitly

circumvent the native adaptive responses of immigrant high-latitude grapes

to daylength patterns of the lower latitudes. Three specific approaches

can be recognized: 1) Adaptive Insolation Optimization; 2) Adaptive

Pruning; and, 3) Adaptive Hybridization. They have emerged as regional

practices that are presumably successful under the geo-environmental

conditions where they developed. When a locally adaptive tradition is

introduced to a different latitudinal region, it may, of course, become


Adaptive Insolation Optimization

Adaptive insolation optimization concerns the interpretation of

solar intensity and daylength interactions with seasonal and diurnal cloud

cover patterns. The interplay of physiological and geographical factors

underlying insolation-adaptive viticulture has been understood by

viticulturists since ancient times. European immigrants in the New World

tropics and subtropics sought out locations for viticulture guided by the

perception of environmental analogy between colonial and Old World


Apparent similarities of vegetation and soils have served to

identify semi-arid areas that provide the high levels of insolation known


to be essential for adequate development of fruit buds, blooming, fruit

set and maturation in Old World grapes (Baldwin, 1964; Kliewer,1981).

Such areas, where clear skies prevail, are in fact the major commercial

vineyard locations in the American tropics (Pansiot and Libert, 1970;

Boubals, 1988a).

Even such seemingly favorable areas tend to be perceived as somehow

environmentally inferior to the "old country." Under shorter daylength

regimes, most cultivars of European V. vinifera become relatively

unproductive, develop poorly and are prone to physiological maladies in

regions below the 30th parallel (Winkler, 1962; Branas, 1974).(4)

Controlled environment research suggests that the daily duration of photo-

inductive daylight is a regulator of adaptedness and productivity separate

from that of solar intensity, with which it interacts to some degree

(Buttrose, 1974).

On the other hand, low latitude regions with warm rainless periods

are partially analogs of the Mediterranean growing season, uninterrupted

in the tropics by extremely short days and rest-enforcing cold weather.

Although summer days in the tropics are shorter than those at higher

latitudes, tropical winter days are considerably longer than those at

latitude 30 N, the approximate southern viticultural border of the

Mediterranean subtropics. Therefore, reduction in native fertility of

adaptable immigrant cultivars is offset, often to a surprising degree by

more or less continuous cropping (Corzo, 1987).

The influence of latitudinal daylength on grape phenology is subject

to modification by the diurnal pattern of seasonal cloud cover and by

local topography and temperature regimes as well. Reduction of effective


daylength by morning or evening tolda can be enhanced by mountains that

intersect the angle of incidence of the sun (Mac Hattie and Schnelle,

1974). Thus, narrow interior and coastal valleys bordered by north-south

ranges can be influenced by tolda much more than the highlands that rise

above them. Herrera was emphatic in stating that: "Valleys, mainly if

they are deep, are the worst of all places for vineyards." (Herrera, 1513:

p. 55).

Immigrant high-latitude viticulture would be expected to adapt best

to locations least disadvantageous in terms of interactive daylength-

restricting topographic conditions. In addition, favored sites should

have locations that counteract high atmospheric humidity. For example,

viticulturists throughout the Caribbean would agree with the Sevillean

agronomist Ibn Al-Awwam (of 12th century Seville) in that:

Grapes prosper by the sea, and are benefitted by maritime breezes,
which is not the case in the vicinity of rivers where there are
marshes and lagoons. (Ibn Al-Awaam, 12th century: p. 214)

On the other hand, cool temperature regimes of tropical highland climates

seem to counteract the inhibitory effects of inadequate daylength on some

high latitude cultivars (Sugiura et al., 1975).

Adaptive Pruning

Pruning is the primary cultivational technique used to control and

optimize production of grapes in a particular geographical environment.

Its adaptational purpose is to coordinate fruiting phenology with

relatively favorable climatic conditions, including optimal effective

daylength. Thus, the calendar of pruning in varying photoclimatic regimes

at different latitudes is a major concern of adaptive viticulture.

Reproductive and vegetative development in grapes, as in other

perennials, is controlled mainly through leaves and buds that sense and

respond to seasonal changes in daylength stimuli (Vince-Prue, 1975).

Flower clusters emerge and develop with new growth from fertile buds

formed during the preceding growth season (Kobayashi, et al., 1966;

Buttrose, 1969a). At the same time, new buds are formed containing the

flower initials that would normally develop in the following growing

season. In the higher latitudes, where most cultivated grapes have

originated, new buds are formed in an environment of rapidly expanding

daylength and luminescence.

To be adaptable in the tropics, non-native cultivars from higher

latitudes must be tolerant of relatively short photo-inductive daylengths.

For those that do adapt, productivity depends on a sufficient daily

duration of high level insolation (Kliewer, 1981). Cumulatively, a season

with such days long enough for completion of the critical formative stage

(Buttrose, 1969b) is required. In the tropics, therefore, pruning must

be scheduled so that critical fruit-bud formation occurs during

predictable periods of relatively clear skies, and, preferably, with

daylengths of twelve or more hours.

Conversely, mature leaves respond to shortening days by directing

the physiological process towards vegetative rest or inhibition (Hackbarth

and Scherz, 1935; Moschkov, 1935). In the leafless vine rest is

maintained by the collective influence of daylength receptive dormant buds

(Alleweldt and Istar, 1969). After a period of vegetative inactivity,

when daylength again increases beyond the equinoctial threshold, the

reproductive cycle is reactivated with the oncoming season's growth.


Pruning may have developed as an adaptive technique when viticulture

diffused into areas subject to late killing frosts, as a means of

retarding spring budbreak. Because of apical dominance, when buds begin

to swell in spring, pruning delays budbreak temporarily (Rives, 1967;

Pool, 1984). However, since pruning uninhibits vine growth by eliminating

the distal buds that register and regulate daylength control of vegetative

activity, it can prove to be counter-adaptive if done too early (Ibid.).


The classical agronomists generalized that early pruning (November-

December) should be the rule in areas where cool winter weather arrived

early and remained constant until spring. Late pruning (February-March)

was considered advisable in areas with relatively warm winters, subject

to late freezes. This practice conveniently anticipates the equinoctial

change to longer days.

Dates for pruning grapevines differ substantially between

latitudinal subregions of the Caribbean. In the mid-region islands of

Puerto Rico and Hispaniola the custom of late pruning as practiced in

Arabic Andalusia--as described by Al-Awwam--still prevails. An annual

cycle of cropping which follows the rise and decline of latitudinal

daylength is thereby established. Both Florida, located roughly between

latitudes 250 and 30 N, and the Greater Antilles at nearly latitude 20N

have been restricted to a single yearly pruning, because of the

inevitability of freezing weather in the first case, and because of the

inhibiting effect of relatively short "off-season" daylengths in both



It is in the southern borderland of the Caribbean, at a

significantly lower latitude, that pruning attains its greatest potential

as an adaptive technique. In Venezuela (latitude 10N), where winter

daylengths are near the equinoctial threshold, pruning has been used

advantageously since early colonial times (Latorre, 1919) to promote

reproductive new growth during periods of high insolation throughout the

year. Even without pruning, the best adapted of the introduced cultivars

tend to grow in vegetative flushes the year around following changes in

available insolation levels and effective daylength (Purohit et al.,


Adaptive Hybridization

The use of hybridization as an adaptive technique in New World

viticulture has evolved from the experience that hybrid forms often

combine desirable traits of widely differing "races." The recognition and

selection of hybrids between indigenous forms and introduced cultivars has

been traditionally understood as essentially adaptational, although

appraisal of environment conditions has usually focused on "disease

resistance" rather than on daylength. Though evidence of colonial grape

breeding is rare, the exploitation of hybridity requires only the

recognition of sexual reproduction in grapes. A practical understanding

of plant sexuality was part of the Arabic agricultural legacy of Andalusia

at the time of the Discovery. On describing the well documented ancient

technique of hand pollinating the date palm, Ibn Al-Awwam adds:


Some horticulturists say that all trees are susceptible to talkih
or fecundation, by which means they yield very good fruit, and these
drop off less, and so it is said that all trees being male or
female, the latter are fecundated by the former. (Ibn Al-Awwam, 12th
century: p. 291)

Talkih, he explains, is the dusting of flowers on a female date palm with
"seminal dust" (pollen) from a male date palm.(7)

When the New World was colonized, Spanish agriculturists were well

aware that many orchard crops need cross pollination, and that some are

dioecious (separately sexed) like the date palm (Herrera, 1513).(8) All

species of grapes are largely dioecious in the truly wild state (Levadoux,

1956). While selection has made functional hermaphroditism the prevalent

condition in cultivated grapes, exceptional female cultivars have been

handed down through the centuries. Such is the Ohanez of Almeria, a

traditional Andalusian export grape which is artificially pollinated in

the same manner as date palms (Rueda-Ferrer, 1953).

Herrera advocated interplanting a few males in orchards of female

cultivars. Attributing fecundity to male "odor" (pollen?) and "heat"

(Herrera, 1513: p. 113), he alternatively proposed grafting female scions

on male rootstocks. Both practices enhance the possibility of

interspecific hybridization. Spanish horticulturists were presumably

aware of this. It is implicit in Herrera's praise of grafting:

With [grafting] more than any other craft wild trees become
domesticated, the sterile become fertile, the good much better.
[Grafting] is the cause for there to be each day new kinds of fruits
which did not exist anciently, nor were created at the beginning of
the world. So much so, that there are scarcely less trees invented
than natural, as from two species of animals a third is engendered
that is very different. (Herrera, 1513: p. 120).(9)

Grafting has long been appreciated as a means for quickly

establishing productive vineyards in newly colonized lands. The basic


idea is that well-developed native vines be used as adapted rootstocks,

following the general rule that "where there are similar wild species

doing well, domesticates of their own kind can be planted." (Herrera,

1513: p. 101). There is little doubt that Spanish grapes in the New World

colonies were routinely propagated and grown on stocks of native American

grape species. Expressions of wonder at the abundance and fertility of

the native grapevines are found throughout accounts of the Contact period.

In the circum-Caribbean mainland and major islands, V. caribaea was

common (Levadoux et al., 1962; Olmo, 1968). In Florida a surprising array

of grape species, possibly including indigenous cultivars, awaited the

Spanish settlers (Sauer, 1969, 1971; Rogers and Mortensen, 1979). A

bewildering diversity of forms was available in Mexico (Olmo, 1976).

Cortes, the Conquistador of Mexico, made sure the indigenous vines were

put to good use, and in his "Ordenanzas" of 1524 decreed that every

settler who received an allotment of land and Indians was obliged to plant

a proportionate number of native vines as rootstocks, to be duly grafted

with scarce scion-wood from Spanish cultivars (Adams, 1978).

A widespread common name for V. caribaea on the mainland is agras.

The term was applied in Spain to special purpose acidic grapes. In the

northern part of the peninsula, acid juice was obtained from wild grapes

as a culinary and medicinal substitute for vinegar and sour orange, while

in the south such grapes were regularly needed to balance the chronically

acid-deficient wine musts of the hot climate. If suitable wild grapes

were unavailable, a late crop that would not ripen was intentionally

induced on cultivated vines by summer pruning. It seems likely,

therefore, that wild Caribbean grapes would have been planted in, and


tolerated near, colonial vineyards for supplementary must as well as for

rootstocks and improved fecundation.

The vicinity of native vines in field-border hedgerows is a

condition sufficient for cross-pollination between wild and cultivated

grapes. All grape species of the major subgenus (Euvitis) have the same

number of chromosome pairs (2n=38) and will produce fertile hybrids if

cross-pollinated (Rives, 1974). The blooming periods of many species

often overlap, more so if synchronized by pruning (by either human or


An abundance of interspecific hybrid grape seeds was a likely

occurrence in colonial vineyards, whether or not intentional breeding was

practiced. Seedling vines with exceptional "hybrid vigor," productivity

(in part through expression of hermaphroditism), and adaptedness (notably,

appropriate daylength programming) to environmental conditions would have

been recognized, selected and propagated. Adaptively superior hybrid

vines would have gradually replaced the short lived V. vinifera as they

died out.

Despite a ban on commercial viticulture in the Spanish colonies by

Philip II in 1595, the religious orders were exempted and vineyards

continued to be planted, especially in the frontier mission settlements

(Adams, 1978). Elsewhere, grapes became dooryard garden plants.

Eventually hybrid "creole" or "mission" cultivars have been handed down

and achieved economic prominence in every viticultural region of the

Hispanic New World, including each of the three latitudinal regions

represented in this study.


To summarize, it has been proposed in this chapter that the

geographical limiting condition in the diffusion of viticulture toward the

equator is the diminishing calendar range of photo-inductive daylength,

which is reflected in the phenological responses of cultivars originating

beyond the tropics, where the range is progressively greater and

phenological adaptation critical to survival. The condition is enhanced

on one hand by the additional seasonal reduction of effective daylength

resulting from periods of persistent cloud cover (tolda), and on the other

hand by the basic physiology of grapevines which uses daylength under

twelve hours to store metabolites for future growth, and daylength beyond

that threshold for productive phenology (i.e., flowering and fruiting).

The above proposition is grounded in the findings of researchers

from ancient times to the present. The introduction of viticulture to the

tropics has relied on three distinct adaptive techniques, all empirically

based on the underlying need to optimize the interaction of grapevine

physiology with the variable daylength environment. Historically, the

most primitive technique appears to be adaptive insolation optimization,

to which later was added the complementary techniques of adaptive pruning

and adaptive hybridization.

Historical analysis suggests that none of the two latter techniques

have evolutionary precedence, nor are they incompatible. However, in the

following chapters it will be shown that fortuitous geographical

circumstances (geo-environmental and cultural) have favored the

development of either approach on a regional basis, to the exclusion and

virtual banning of the other!

Chapter 3 seeks to clarify the obscure origins of modern adaptive
hybridization in the New World (specifically in Florida), and its

curiously limited geographical diffusion as an institutionalized

scientific approach. Chapter 4 examines the more recent establishment of

the alternative technique, adaptive pruning, as a comparably sophisticated

approach that has likewise failed to spread appreciably beyond its area

of origin. Chapter 5 raises the question of whether the two approaches,

paradigmatically entrenched in scientific institutions, can be reconciled.

1. "Heat summation" differentiates climatic regions by computing the
sum of mean daily temperatures above 50F (10C) during the growing
season. Its opposite term, the so-called "chilling requirement,"
presupposes that a certain number of hours under the same threshold
is needed to fulfill a required period of dormancy.

2. Tropical rainfall tends to follow a predictable seasonal and diurnal
course which is most intense during the high sun period (Ramage,
1971), thereby restricting the daily duration of photo-effective
daylight between the spring and fall equinoxes. In the tropics,
effective daylengths may be longer during brief equinoctial and
winter solstice dry (i.e. cloudless) periods when calendar days are
relatively short, especially so by comparison with daylengths of the
growing season in higher latitudes.

3. All true grape species are native to the Northern Hemisphere
(Levadoux et al., 1962). In the New World the number of recognized
forms diminishes dramatically toward the equator. Apparently, none
have spread naturally across the equatorial line.

4. Certain vinifera cultivars commonly grown in the tropics are
exceptionally tolerant to low latitude daylengths. Several
cultivars that have been successful were selected for "forcing" in
19th century European greenhouses (Miller, 1963). They appear to
have derived largely from Persian and Arabian lineages selected
since ancient times south of latitude 30N and beyond the Tropic of
Cancer possibly as far south as the Gulf of Aden at latitude 150N
(Levadoux, 1956). Well known are the characteristic "Muscats."
However, these "desert" grapes are generally intolerant of high
atmospheric humidity.

5. In Florida, where warm winter weather allows vegetal growth, the
custom of early pruning may be responsible for freeze damage and
subsequent infection with Pierce's disease, the most important
"natural barrier" to viticultural adaptation in Florida (Crall and
Stover, 1957).

6. On the islands, however, two or three successive crops (of uneven
quality) are possible with some cultivars, a fact noted as early as
1582 in a "state of the colony" report on Puerto Rico for the King
of Spain (Latorre, 1919).

7. Cowan's (1976) Arabic-English Dictionary defines talkih as either
plant pollen/pollination, or animal (and human) sperm/insemination.
The Arabic terms for horticultural budding and grafting are derived
from the same root.

A common colloquial expression in Puerto Rico, and other Hispanic
lands, refers to human sexual intercourse, specifically
insemination, as "echar un polvo," literally: "To (throw a) dust."
The original meaning has been lost but the derivation seems clear.

8. Although Vernet (1978) affirms that Herrera took his notions of
applied plant sexuality from Arabic texts, early settlers in the
Hispanic Caribbean gave common names to a few native trees which
reflect continuity of the folk belief that small differences between
otherwise similar forms (actually related species) imply separate
sexes of the same species (Gilormini, 1979). By contrast, common
awareness of plant sexuality in most of Europe had to wait for
experimental confirmation by Bobart, Camerarius and Grew in the 17th
century (Wolf, 1952).

9. Herrera may have thought that hybrids associated with grafts are
graft or vegetative hybrids, actually quite rare (Hartmann and
Kester, 1968). Graft failure on intended native rootstocks would
thus augment interspecific "intimacy" and consequent production of
hybrid seeds.


The present chapter elaborates on a previous investigation which

suggested that early Spanish colonial Florida had a particular

significance in the introduction of viticulture to the New World

(Watlington-Linares, 1983). In that report, the author proposed a

thorough examination of grape seeds as archaeobotanical evidence to

determine whether adaptive hybridization had taken place in the first

European settlements. Eventually, the opportunity arose to examine a

significant sample obtained from a late 18th century mission village in

east central Florida which offered important clues. Thus, the sources for

this inquiry include archaeological grape seeds, as well as available

documents, direct observations in the field, and the first-hand testimony

of modern pioneers in adaptive grape breeding.

Modern adaptive viticulture in the southeastern United States is

based largely on native interspecific hybrids, including foundlings of

antique origin and their descendants. Sauer (1969, 1971) suspected

prehistoric aboriginal domestication. Others (Munson, 1909; Fennell,

1941; Bailey, 1948; Rives, 1963) have generally assumed that such vines

originated as natural hybrids of wild species, or between native grapes

and European cultivars. It is possible that some of the vines in question

may represent survivals of adaptive hybridization in early Spanish



Domesticated grapes appear to have evolved originally in the Old

World from discovery, collection and vegetative propagation of natural

hybrids combining fruit and vine traits of separate forms in advantageous

ways (De Candolle, 1886; Sauer, 1971). Replication of such an origin was

observed by Olmo (1970) in an ethnographic context in northwestern India.

Comparative studies of archaeological and living seeds suggest that the

cultigen continued to develop and spread as primitive selections were

taken to new geo-environmental areas and interbred with local wild and

cultivated ecotypes (Levadoux, 1956; Negrul, 1960; Rives, 1974; Janusevich

and Nikolaenko, 1979).(1)

C. 0. Sauer (1969) may have been the first to propose continuity of

Amerindian grape cultigens from prehistory to the present. The prominence

of grape seeds in archaeobotanical samples obtained by flotation since the

early 1970s (Watson, 1976) suggests that some aboriginal peoples may

indeed have practiced incipient viticulture between the late Archaic

period (4500 2500 BP) and the 18th century. Sauer's conjecture has

apparently not been seriously investigated previously.

Surprisingly, the existence of mission vineyards tended by Indian

labor from the late 16th to late 18th century was overlooked by Sauer, and

likewise ignored by archaeological researchers of Hispanic agriculture.

Most notably, grapes were left out of Ford's "Hispanic Complex" of

cultivated plants introduced by the Spanish and adopted by Southeastern

Indians (Ford, 1981). Since they were already avid consumers of fresh and

dried native grapes, there is little reason to believe the Indians did not

accept European grapes as readily as they did oranges, peaches, figs,


pomegranates and watermelons, all of them Old World fruit crops (Smith,

1956; Mason, 1963; Blake, 1981; Ford, 1981; Newsom, 1986; Reitz and

Scarry, 1985).

The Florida Mission Graves

Grapevines from Spain were introduced to the Caribbean region with

Columbus' second voyage (1493) when a vineyard was planted on the island

of Hispaniola (Sauer, 1966). Viticulture followed Spanish colonization

throughout the New World. Vineyards were planted and in many cases

maintained against environmental odds to assure a regular supply of wine,

a cultural staple vital to the social solidarity of the conquistadors.

Moreover, documentary and material evidence supports the proposition that

the process of adaptive hybridization postulated for Old World viticulture

continued in the New World, specifically in early Hispanic Florida.

In Florida, hybrid grapes may have first appeared in settlements

established by Spanish colonists in the late 16th century. During that

period also, the seasonally migrant Guale Indians were sedentized in

mission controlled villages on the Atlantic coastal Sea Islands from the

northern Spanish outpost of Santa Elena to St. Augustine in the South

(Gannon, 1965).(2) Of necessity, Spanish and Indian crop systems became

integrated in a new, "mestizo," agricultural complex (Matter, 1973).

Excavation (South, 1980) has confirmed historical reports that the

first Spanish vineyard in Contact Florida was planted at Santa Elena, on

what is now Parris Island, South Carolina, in 1566 (Watlington-Linares,

1983). The colony initially surpassed St. Augustine, until its

destruction in 1576 (Lyon, 1976). Although quickly rebuilt and


refortified, the vineyard replanted, the outpost lost its pre-eminence to

the more secure southern position. Officially abandoned eleven years

later (1587) under threat of Indian rebellion, apparently the settlement

did not disappear entirely.

Waring (1970) noted that a Captain William Hilton of Barbados

visited Santa Elena in 1663. He found "Spanish" Indians living there,

seventy-six years after the presumed abandonment of the former mission

village. They lived amid artifacts that included a standing wooden cross,

and orchards of peaches, figs and grapes. That these were not relics but

actively cultivated there can be little doubt. With the exception of

native grapevines and their adapted hybrids, capable of self renewal by

spontaneous layering, the exotic peach, fig and European grape are

reputedly short lived in the Southeast without skilled husbandry.(3)

In 1735, Francis Moore, an English visitor to Georgia, accurately

described the two common native wild grape species, V. aestivalis Michx.

and V. rotundifolia Michx. He then commented on a curiosity he had seen

on St. Simon's Island, site of the mission of Santo Domingo de Asaho:

But there is on St. Simon's, a wild Grape much nearer the Europe
Vine, the Fruit being exactly the same as the common white Grape,
though the Leaf is something different. The Birds and wild Animals
like it so well, that they suffer it seldom to ripen. All the Vine
Kinds seem natural to the Country. (Moore, 1744: p. 55)

Similarly, late 18th century settlers discovered feral grapes of

apparent V. aestivalis x vinifera hybridity (Rea, 1941; Mishkin, 1975),

growing within the former Hispanic/mission, and subsequent Anglo-Indian,

borderland in South Carolina, Georgia, and Alabama. This buffer zone,

then populated by remnant Indian tribal communities, included Hispanicized

villages forcibly relocated by the English upon destruction of the Spanish

west Florida province of Apalache at the beginning of the century (Jones,


San Francisco de Oconi was one mission community that may have

accepted relocation rather than the alternatives of enslavement or

slaughter. Those that went along with the English were settled amid the

Creeks, probably somewhere in the upper basin of the Altamaha River, and

most likely soon assimilated. Eventually, the northern branch of the

Altamaha came to be known as the Oconee.(4) Despite English encroachment,

the area remained under nominal Indian control until 1775 (De Vorsey,

In 1773, while traveling between the Oconee and Savannah rivers,

naturalist William Bartram observed that grapes and other orchard fruits

were cultivated in an Indian village that he visited. He later wrote:

The present nations that inhabit these lands seem very fond of all
kinds of eatable [sic] fruits and nuts and take great care to
cultivate peaches, grapes, plums, & etc. (Bartram, 1775: p. 142)

A few years later, in an ethnographic paper on the Creek of the Oconee,

Bartram again made reference to the cultivated grapes he had seen in their


Vitis vinifera: I call them so because they approach, as respects
the largeness of their fruit and their shape and flavor, much nearer
to the grapes of Europe and Asia, of which wine is made, and are
specifically different from the fox or bull grape of Pennsylvania
and Carolina (Bartram, 1789: p. 49).
By the time of Bartram's visit some Creek had moved out of Georgia

and into northern Florida. A group that had lived on the Oconee River

became established, between 1733 and 1750, in the Alachua region (Tebeau,

1980). The Micosuki, as this people came to be known, was gradually


forced southward, and in the 1820s briefly granted much of central Florida

from Ocala south to latitude 27 N. Isolated groups survived later

campaigns to remove them. It may be that many were gradually absorbed

into the dominant culture of later immigrants.

Feral grapes that appear to be "escapes" from cultivation or

abandoned cultivars from earlier occupation have been recovered in south-

central Florida, as in other Southeastern frontier zones where the Indian

presence lingered.(5) However, the original systemic or behavioral

context of such finds has not been as clearly established as certain

documented survivals from the preceding Spanish period.

In 1823 a surveyor preparing a site plan for the Florida state

capital at Tallahassee discovered the ruins of Fort San Luis, abandoned

one-hundred-nineteen years earlier. It was later reported that "within

the outerworks of this fort, are to be seen grape arbors in parallel

lines, which still maintain their pristine regularity." (quoted in Boyd,

1939: p. 4). Another contemporary observer described a vestigial street

grid nearby, with shade trees and "grape arbors of more or less

regularity." (Ibid.: p. 5). Unless the vines in question were overgrown

rootstocks of native species, their unusual longevity suggests the

possibility of hybrid cultivars.

It is interesting to note that toward the end of the century French

winemaker Emile Dubois established a winegrowing estate on the Fort San

Luis property (Paisely, 1968). Unlike many immigrants who brought in

muscadines (V. rotundifolia) from Georgia and the Carolinas, or introduced

V. labrusca cultivars from farther north (Lewis, 1979), Dubois planted

hybrid V. aestivalis x V. vinifera selections of the "Florida mission"


type. It is unclear what varieties he used to make the red wine that won

recognition at the Paris Exposition of 1900.

An Archaeological Clue

The widespread occurrence of feral hybrid grapevines is not

unequivocal proof that intentional hybrid viticulture, much less grape

breeding, took place in colonial Florida. It has been suggested that the

conventional botanical classification of grape species and supposed

subspecies is "illusory" (Rives, 1971) because of the observed frequency

of spontaneous hybrids between geographically coterminous forms. Another

researcher proposed "indefinite specific limits" (Bailey, 1948).

Intermediate forms have been noted as especially common in the

anthropogenic environments produced by fire, cultivation and grazing

(Rives, 1963, 1971; See also: Chapman, et al., 1982). It has also been

proposed that central Florida is a likely center of origin of new

botanical forms emerging in the interface of formerly isolated peninsular

species (Woodson, 1947).(6)

A cultural context has not been definitely established for the

origin of any foundling Florida grapevine adopted as a cultivar or proto-

cultivar (for breeding purposes) in modern times. However, because

natural hybridization is an ephemeral phenomenon (Rives, 1963; Anderson,

1949), the survival and diffusion of a hybrid grapevine may denote both

environmental and cultural favor. A natural hybrid may easily become an

artifact of material culture by means of asexual vegetative propagation.

Grape seeds of apparently hybrid morphology were recovered from a

historical archaeological context in Hontoon Island, central Florida


(latitude 2910'N, longitude 8130'W) by Purdy and Newsom (Newsom, 1987)

in 1982. The site comprises a sequence of aboriginal occupations

culminating in an agricultural (mission) settlement during the Spanish

colonial period. Charred grape seeds are among the more common floristic

remains at all levels. This is not surprising in view of the fact that

large scale smoke-drying of grapes was practiced by Indians in the

Southeast from prehistory through Contact (Sauer, 1971) to the late 18th

century (Bartram, 1775).(7)

Following Rogers and Mortensen (1979), most of the grape seeds from

Hontoon were tentatively identified as belonging to five broadly defined

species found in central Florida, and a few incidental hybrids.(8) The

most notable find is a substantial sample of 51 well preserved, apparently

charred, specimens which has been dated to the historic period, ca 1775-

1800 (Volumetric Sample 5, obtained 40 to 50 cm below the surface of the

dig). The sample is composed exclusively of relatively large bunch grape

seeds (Euvitis) of extraordinary and uniform appearance (Figure 2).

Interpretation of the VS 5 sample, provisionally named "Vitis x

hontunensis," was possible only after a considerable search for comparable

herbarium and living specimens.(9) No survey was made of grapes presently

found on Hontoon Island. The V. x hontunensis seeds have been found to

closely resemble the shape and dimensions of two supposed taxonomical

species, V. simpsoni Munson, otherwise known as "Simpson's Grape," and V.

gigAs Fennell, the "Florida Blue Grape."

The two forms share the horticultural attribute of bearing

relatively large clusters of comparatively large berries. This

combination of traits is rare in nature, but can occur when a small

dorsal view

ral view

frontal view

lateral view

Hontoon Grape seed (Vitis x hontunensis), enlarged
approximately ten times. Drawn by the author.

Figure 2.



cluster, large seed, large berry form, specifically V. shuttleworthi House

of southern Florida (syn. V. coriacea Shuttleworth), hybridizes with large

cluster, small berry species such as V. vulpina L. (V. cordifolia Michx)

or V. aestivalis Michx. of wider distribution. Both "gigAs" and
"simpsoni" have been alternately described by the creators of the taxa and

by others as possible hybrids of such origin. V. x hontunensis may

represent a similar hybrid form.

A pioneer of modern adaptive grape breeding, T.V. Munson recognized

and made extensive practical and promotional use of such forms. In the

late 19th century, Munson grew in his vineyard at Denison, Texas (latitude
3345' N), propagules of several central Florida grapes supposed by the

collectors to be natural hybrids of V. coriacea (V. shuttleworthi) with

other species, namely V. cinerea, V. cordifolia (V. vulpina) and V.

aestivalis (Munson, 1909). However, such finds which continue to occur

(10), were common enough before large scale destruction of the native

vegetation to result in the elevation to specific status of some

foundlings by Munson. In 1887 he described taxonomically a V. simpsoni,

honoring the collector J. H. Simpson of Manatee, Florida (Munson, 1887).

Ten years later Munson established a second "Simpsoni," of more promising

horticultural appearance (Bailey, 1934).

Munson eventually downgraded his first simpsoni to V. cinerea var.

floridana (Munson, 1909). The ensuing taxonomical confusion has occupied

subsequent ampelographers from Viala (1889) and Bailey (1934) to Rogers

and Mortensen (1979). Bailey, in particular, compounded the problem by


renaming the second "Simpsoni," V. smalliana, and insisting that his

description applied to Simpson's intended "Simpsoni":

This is undoubtedly the plant understood as Simpsoni by Simpson
himself in a communication of Nov. 8, 1898, in which he says,
"bearing vines [i.e. female clones] seldom found except on shell
mounds near salt water." (Bailey, 1934: p. 207)

Meanwhile, in 1888 a French mission led by Viala examined Munson's

collection of "Simpsoni." Later Viala (1889) described what he saw as a

hybrid "mel~nge" of V. coriacea (shuttleworthi).(11) The "type" that he

returned with to France was identified as "Nash no. 399" from Lake County,

central Florida. A plate and measurements by Bonnet (1902), and a plate

by Gillet published years later by Viala and Vermorel (1910) are

presumably representative of the Viala accession in the Montpellier

collection. All are in agreement with Munson's (1909) brief description

of V. simpsoni. Both descriptions are congruous with the recovered

V. x hontunensis. A comparable sample of 49 seeds was obtained as a

medium (15 cm) cluster of fruits from a vine in the Leesburg (Lake County)

Agricultural Research Center germplasm collection. The medium cluster,

large-medium berry clone is listed as "Florida no. 399, V. smalliana


A second comparable sample comprises 20 seed specimens from the

original and only known botanical type of V. Sigcas Fennell (1940): Sample

no. 2216242 in the U.S. National Herbarium (Smithsonian Institution).

Fennell described an isolated population of vines which seemed akin to V.

aestivalis, and bore impressively large clusters of large berries with

meaty, sweet and tangy pulp. Proclaiming his find a new species: V.

Sjicis, Fennell described its habitat as restricted to "the dry shelly


banks of brackish waterways and lagoons" on the Sebastian River, ca.

latitude 27*50' N (Fennell, 1940: p. 17).

Fennell implicitly admitted the possibility of a hybrid origin for

his "Florida Blue Grape":

In a few cases it takes close observation to distinguish by foliage
alone the Florida blue grape from some of the natural hybrids of V.
shuttleworthi or of V. simpsoni (V. cinerea floridana). (Fennell,
1940: p. 17)

Fennell has never published his retrospective suspicion that his

foundling might be a remnant of antique viticulture (Fennel, p.c. 1984).

A collector of native grape hybrids in the wilds of southern Florida in

the 1930s, he was lured to ajgs by reports of exceptional dooryard bunch

grapes in the vicinity of the hamlet of Mico (an Indian word for chief).

Recently he read of archaeological digs in the same area (Tequesta) and

reflected that his best finds had been associated with Indian shell

mounds. This coincides with Bailey's observation concerning a similar

habitat for Simpson's Grape.

Comparative measurements of V. x hontunensis and the living forms:

Florida no. 399 (Simpson's Grape or VS), and V. gigqs (henceforth

Fennell's Grape or VG) are summarized in Tables 1, 2, and 3.(13) Despite

overall resemblance among the three types, the absolute and relative

measurements of each sample reveal distinctive differences as well as

similarities. Although seed morphology suggests the three forms are

closely related, their dimensions are indicative that they have separate


The V. x hontunensis (henceforth Hontoon Grape, or VH) seeds appear

to be in the same size category as Simpson's Grape (VS). Newsom (p.c.

1988) believes the degree of carbonization of the VH sample is open to

question. If compared directly, the absolute dimensions of VH fall into

the size range of the smaller VS, except for one feature, the chalaza,

which averages 16% larger in the VH seeds.

If 18% shrinkage is allowed for in the archaeological sample, and

the VS similarly "reduced," the longest (i.e. the "largest") VS become

equivalent in length to the mean for the "large" VH. (14) In addition,

31% of the VH seeds represent potentially greater live lengths, roughly

7 to 7.2 mm. All together, the longer VH seeds (43.75%) appear wider by

14.7% and thicker by 10% than their VS counterpart (the "largest" VS

comprise 18.36% of their sample).

The chalaza of the VH appears much larger than the shrinkage

adjusted value for all the VS. The mean is 31% larger, but the largest

VH seeds have chalazas 35% wider than the widest VS (surprisingly the
"small medium" seeds). The mean "diameter" of chalaza for all the VH is

also 31% larger than the adjusted mean for the largest chalaza of

Fennell's Grape (VG). The advantage is 17% for the unadjusted

measurement. Curiously, the "median" VG seeds have the largest chalaza.

Comparison of the relative dimensions for VH and VS tends to confirm

the visual similarity of proportions between the two forms. Small VS

seeds (2.24%) have a mean L/W ratio of 1.25, identical to the value for

"large" VH. The "small medium" VS (28.5%) have an L/T ratio of 1.82,

identical with the value for the largest VH. The whole VS sample has an

L/T value of 1.81, virtually the same as the "largest" VH. The L/W ratio

of the chalaza for all VS is 1.22, almost the same as the mean for all the

VH (1.20).

Table 1. Hontoon Grape Seeds, Summary of Comparative Measurements (mm)

Mean Mean Mean chalaza
Category Sample Length Width Thickness L/W L/T 5/W L/W

Largest (longest) # %
(5.85-5.975) 6 12.50 5.92 4.56 3.25 1.29 1.82 1.76 1.15
Larger (longer)
(5.62-5.75) 9 18.75 5.67 4.57 3.41 1.24 1.66 1.62 1.19
Large (long)
(5.50-5.57) 6 12.50 5.53 4.52 3.15 1.22 1.75 1.52 1.30

All Large 21 43.75 5.70 4.55 3.27 1.25 1.74 1.63 1.21

Medium (length)
(5.40-5.475) 10 20.80 5.45 4.54 3.04 1.20 1.79 1.54 1.23
Small Med. (lgth.)
(5.07-5.35) 12 25.00 5.23 4.34 3.43 1.20 1.52 1.58 1.18

All Medium 22 45.83 5.34 4.44 3.23 1.20 1.65 1.56 1.20

Small (length)
(4.75-4.975) 5 10.41 4.88 4.27 3.12 1.14 1.56 1.47 1.19

All Seeds 48 100.00 5.45 4.47 3.23 1.21 1.68 1.58 1.20

Source: Direct measurements by Lee A. Newsom (1985), Department of Anthropology, University of
Florida, Gainesville, with "Manostat" dial type 6921 caliper. Classification, means and
ratios by the author.

Table 2. Simpson's Grape (Fla. 399) Seeds. Summary of Comparative Measurements (mm)


Largest (longest)
Large (long)
Small Large

All Large

Small Medium
Small (length)

All Seeds











chal aza



































1 .86


















Direct measurements by Lee A. Newsom (1985), Department of Anthropology, University of
Florida, Gainesville, with "Manostat" dial type 6921 caliper. Classification, means and
ratios by the author.

Table 3. Fennell's Grape Seeds, Summary of Comparative Measurements (mm)






chal aza

Largest (longest) # %
(6.025-6.20) 7 35.00 6.08 3.92 2.98 1.55 2.04 1.20 1.38
Median (long)
(5.80-5.95) 5 25.00 5.86 4.00 2.89 1.46 2.02 1.21 1.30
(5.625-5.75) 6 30.00 5.67 3.95 2.86 1.43 1.98 1.14 1.35
(5.475) 2 10.00 5.47 3.83 2.77 1.43 1.97 1.12 1.47

All Seeds 20 100.00 5.77 3.92 2.87 1.47 2.00 1.17 1.37


Direct measurements by Lee A. Newsom (1985), Department of Anthropology, University of
Florida, Gainesville, with "Manostat" dial type 6921 caliper. Classification, means and
ratios by the author.


Comparison of the Hontoon seeds with those of VG is limited by the

size and structure of the latter sample. Fennell apparently selected

representative seeds in terms of their number per fruit. The twenty seed

sample is based on two single seed berries (10%), three 4 seed berries

(60%), and one six seed berry (30%). There does not seem to be a clear

correlation between seed dimensions and number of seeds per berry.

Compared directly, (15) the longer VH seeds fall into the mean

length for VG (5.70 vs. 5.77) with a similar "median" of 5.67. The mean

width for all VH seeds, however, is 12.30% greater than that for the VG.

The mean thickness of the VH is also greater than that of the VG, by 11%.

The chalaza is 20% larger in the VH.

In relative dimensions there are corresponding differences that

belie the remarkable likeness between the VH and VG seeds. The L/W ratio

of VG is 17.7% higher (indicating a somewhat narrower form), and the L/T

ratio 16% higher (somewhat thinner), than the VH. The L/W value for the

VG chalaza is 12.4% higher, indicating a relatively elongated outline.

In general, the compared measurements show that seeds of the Hontoon

Grape are morphologically akin to those of Simpson's Grape and Fennell's

Grape. At the same time they are clearly distinct, individually and

collectively. Yet all three types were found in the same anthropogenic

context (shell middens), and within the same geographic area of south

central Florida. Is the archaeological grape a precursor of the two

living forms with similar seeds, that share horticultural attributes?

The possibility that the Hontoon Grape seeds represent an

archaeological cultivar raises further questions. The seeds of the three

forms compared do not suggest hybridization between a native type and


European V. vinifera, but rather between native American species.

Foundling "mission grape" cultivars such as Herbemont and Black Spanish

have seeds readily discernable as intermediate in form between V.

aestivalis, a likely parental species of VH, and V. vinifera. Two

characteristic features of the European Grape, namely: 1) pronounced beak;

and, 2) chalaza located well above the center of the dorsal face, are

present in the "mission" foundlings, but absent in the three samples


Elucidation of the ancestry of Simpson's and Fennell's foundlings

will have to await more sophisticated techniques of genetic analysis.

However, mention of Sauer's proposition of aboriginal grape cultivars is

relevant at this point. Sauer (1971) inferred that three modern American

cultigens V. rotundifolia, V. labrusca, and V. aestivalis were of pre-

colonial origin. The historical record supports reasonably well the case

for Indian muscadine (V. rotundifolia) viticulture (Mishkin, 1975; Gohdes,

1982). The evidence in favor of V. labrusca is at best tenuous.

The argument for V. aestivalis is complicated by the extensive range

of the species, taxonomic recognition of several geographic subspecific

forms, and widespread evidence of hybridization with other species. For

example, after a survey of herbaria, germplasm collections and the field,

Rogers and Mortensen (1979) recognized five subspecies of V. aestivalis

in Florida: 1) aestivalis; 2) sola; 3) divergens; 4) smalliana; and,

5) simpsoni. Following Anderson (1949), Rives (1963), and others, it is

likely that some or all of the subspecific forms could represent hybrid
"swarms" or "men~ges" resulting from interbreeding of the "true"

aestivalis with other species, including the introduced European cultigen.


The territory of V. aestivalis proper covers most of southeastern

North America (Bailey, 1934). In the northern reaches and higher

elevations of its range it gives way to a hardier variant, V. argentifolia

or bicolor. West of the Mississippi River, from eastern Texas and western

Louisiana north to the Ozark highlands of southern Missouri, the

subspecific Post-Oak or Caddoan Grape prevails. Often considered a

separate species, V. lincecumi Buckley, the Caddoan Grape has been

suspected variously as a natural hybrid swarm (Rives, 1963) and as a horde

of horticultural escapes from early mission vineyards (Branas, 1974).

V. lincecumi does suggest hybridity between V. aestivalis and the

large berry V. candicans which shares the southern part of its range and

is closely related to V. shuttleworthi of southern Florida. Sauer (1971)

pointed out that the first missionaries to visit the area (from the

Spanish colonies in Mexico and Florida) were surprised to find the Hasinai

and Caddoans tending grapes similar to theirs. In 1876, T. V. Munson, the

"father" of modern adaptive grape breeding chose to settle in Denison,

Texas on the Red River across from the Indian Territory of Oklahoma

(Munson, 1887, 1909).

Munson made the Caddoan Grape the focus of his breeding work. He

searched land the Indians had not long before vacated and collected

exceptional vines bearing large grapes (around an inch in diameter) in

heavy clusters. These he bred with cultivars of other species and

regions. His selections were widely disseminated. Taken to France, they

became the phylogenetic foundation of modern adaptive grape breeding in

Europe (Galet, 1956) and after World War II in the United States (Barrett,


Interestingly, the seeds of V. lincecumi (VL) described, illustrated

and measured by Bonnet (1902), Munson (1909), and later by Gleason and

Fernald (cited in Steyermark, 1963) appear very similar to those of VH,

VS and VG. Compared directly, the longest VH fits the lower range of

length for VL (7 to 7.25 mm). The mean L/W ratio for VS fits the middle

range for VL (1.40 to 1.33). Countering both Fernald and Gleason,

Steyermark found no correlation between seed size and berry size in the

modern feral population of "V. aestivalis" (i.e. lincecumi) from southern

Missouri. (16) On the other hand, he conceded that "the fruits are sweet

and edible and used for preserves and jelly" (Steyermark, 1963: p.


It is well documented that the Caddoans produced smoked raisins and

had a horticultural tradition that may have included clonal propagation

of selected grape varieties (Swanton, 1946; Griffith, 1954; Perttula et

al., 1982). Munson (1909) described two botanical varieties of the

Caddoan Grape. One was a smaller fruited, sweet and juicy type

appropriate for winemaking. The second was a larger fruited kind,

described as having tough, dry, very acid and astringent pulp, traits that

suggest the possibility of uncommonly good prune-like or apricot-like

raisins. If the large seeds are considered as "grape-nuts," it would seem

the Indians had a superior product by present standards.

A report on a late Woodland Period (ca 1,000 BP) grape seed find

from a typical Caddo site in northeastern Texas mentions the presence of

preserved dried pulp (Crane, 1982). Although the seeds are described as

identical to modern summer grape (V. aestivalis), a photo, inadequate for

lack of scale and resolution is suggestive of V. lincecumi, and of the


Hontoon Grape. Attempts to locate the author and the sample were

unsuccessful, as were efforts to obtain comparative seeds from Munson's

VL derived selections. Whether the Hontoon Grape is closely related to

modern VL or to archaeological Caddoan grapes could not be determined by

the researcher, and remains an open question.

It is not known what purpose was served by the Hontoon Grape,

presumably an Amerindian cultivar, in a settlement of Hispanicized Indians

of the late 18th century. At the time, Bartram observed that similarly

acculturated tribes in Georgia were still making smoked raisins in the

traditional manner, apparently with a cultivar unfamiliar to the


During our progress over this vast high forest, we crossed extensive
open plains, the soil gravelly, producing a few trees and shrubs or
undergrowth, which were entangled with grapevines of a peculiar
species. The bunches (racemes) were very large, as were the grapes
that composed them, though yet green and not fully grown, but when
ripe they are of various colors and their juice is sweet and rich.
The Indians gather great quantities of them, which they prepare for
keeping by first sweating them on hurdles over a gentle fire and
afterwards drying them on their bunches in the sun and air, and
store them up for provision. These grape vines do not climb into
high trees but creep along from one low shrub to another, extending
their branches to a great distance horizontally round about; and it
is very pleasing to behold the clusters pendant from the vines,
almost touching the earth, indeed some of them lie on the ground
(Bartram, 1775: p. 321).

The above quotation unequivocally indicates a non-vinifera bunch grape and

not, as has been recently claimed, a muscadine (Olien and Hegwood, 1990),

or even a labrusca or other native grape of the East, all of which were

familiar to Bartram. On the other hand, his description brings to mind

Munson's foundling Caddoan grapes (V. lincecumi) from Indian territory

west of the Mississippi River, a region unexplored by Bartram, who most

likely encountered a native cultivar, not a wild species.

Curiously, there is no record of transcultural Indian communities

having adopted grape winemaking. In the Spanish missions winemaking and

winegrowing were under religious control, and the use of wine by Indians

generally prohibited. The powerful ritual role of wine in Spanish culture

may indeed have been a reason for the non-adoption of winemaking by the

Indians. However, the possibility that aboriginal uses of grapes were

likewise of religious or ceremonial nature should also be considered.

Fruits such as grapes have been considered by anthropologists mainly

in the context of "gatherer" subsistence strategies, as nutritional

supplements, or "snack foods" (Ford, 1982: p. 304). The unique importance

of grapes as a high energy source, in particular for the lean winter

months, is supported by archaeologic as well as ethnographic data.

The most frequent grape seed finds have been carbonized specimens,

although they have been found in a variety of conditions, matrices and

sample sizes (Yarnell, 1969; Kay, et al., 1980). Although grapes are not

generally accepted as prehistoric domesticates, grape seed remains seem

rather consistently associated with recognized Amerindian cultigens and

horticulture from the late Archaic (Chomko and Crawford, 1978; Chapman and

Shea, 1981) through the Woodland (Pertula et al., 1982) and Mississippian

(Watson, 1980) to the historical periods (Newsom, 1986). (19)

On the other hand, evidence of possible non-subsistence uses of

grapes, such as ceremonial or "soul food" for the living and the deceased,

medicine and dyestuff, although sparsely documented is also available in

the archaeological record. The presence of grape seeds appears associated

in one early site (Late Archaic, ca 4,200 BP) with the presence of gourds,


suggesting a link with shamanist activities. (20) They also appear to be

characteristic of certain mortuary contexts. (21)

Medico-religious uses of grapes have survived in our own society as

a legacy of ancient Mediterranean culture. For example, the special

symbolism of dried fruits, including raisined grapes, in the celebration

of seasonal events is common to the Judeo-Christian and Islamic religious

traditions. Fresh grapes, and raisins also, can be used in effecting a

dietary "grape cure," or cleansing of the digestive tract in ritual

preparation for fasting. Did American Indians have similar traditions

four thousand years ago? If so, the presence and spread of hybrid grape

seeds would mirror the diffusion of early religious beliefs in a way

analogous to the diffusion of wine and winegrowing in the prehistoric

Mediterranean world (Stanislawski, 1975).

A Search for El Dorado

Florida has often been regarded a geographic corridor for biological

and cultural transferal between North America and the Caribbean tropics.

The subtropical native grapes of the peninsula, for example, because of

their adaptedness to hot and humid growing conditions, would be adapted

also, it has been reasoned, to similar conditions between the Tropics of

Cancer and Capricorn.

Modern adaptive grape breeding was emerging in Florida in 1935 (22)

when a visionary young botanist, Joseph Fennell, became enthralled by the

hybrid diversity and attractive cultivar-like traits of the native grapes

he found growing in apparently feral conditions in southern Florida. Like

Munson, whom he sought to emulate, Fennell collected horticulturally

appealing forms and bred them with each other and with cultivars from

other areas (Fennell, 1941, 1945). In the process, he conceived an

ambitious project for developing the foundation of a tropical viticulture.

In 1942 Fennell moved to Puerto Rico where Governor Tugwell offered

support. In 1943, frustrated by political and bureaucratic obstacles, he

moved with his vines from the federal experiment station in Mayaguez to

the Interamerican Institute of Agricultural Science (IICA) in Turrialba,

Costa Rica. Two years later, in 1945, he returned abruptly to Florida

where he continued breeding grapes privately on a limited scale. Fennell

ably memorialized his breeding work in search of a viticultural "El

Dorado" in articles written with contagious promotional enthusiasm

(Fennell, 1944-45, 1945).

Despite claims of success, Fennell's project came to a virtual

standstill in Costa Rica, for various reasons. Extreme cloud cover

(tolda) is characteristic of the growing season in Turrialba

(Schwerdtfeger, 1976) as it is in Mayaguez (Ravalo et al., 1986). (23)

Except for regional accessions of V. caribaea and V. popenoei, most of the

grapevines Fennell grew at the IICA he took there as hybrid seeds and

clones from Florida. Two growing seasons was insufficient time to fully

evaluate their performance.

Fennell (p.c. 1982) would recall that most of his material was

seriously affected by "rust," a mold which in grapes, as in peaches

(Prunus persica), appears mainly on senescent leaves (i.e., a "serious"

attack implies the vines were not growing properly). An exception was

two "true" species introduced from southernmost Florida. V. shuttleworthi

and V. cinerea var. floridana (V. aestivalis ssp. divergens). Both

developed as well as the native V. caribaea, according to Fennell.

Fennell's accounts mention the need to import and preserve pollen

of northern latitude parents as one of his difficulties in producing

hybrids at Turrialba. His known hybrid selections are described as having

originated in Florida, a very few from seeds obtained in Costa Rica.

Evidently, the greater part of Fennell's collection at the IICA was

abandoned by him as unpromising, and eventually died out or was destroyed

when its custodians arrived at the same conclusion. At the end, Fennell

(1947, 1948) hinted that he had become aware of the importance of

daylength as a critical parameter of adaptive viticulture in the tropics.

In 1950, some five years after Fennell's departure, a Brazilian

grape breeder, J. A. Santos-Neto obtained a handful of clones of dubious

phylogeny (24) from Fonnell's abandoned plot in Turrialba. The material

was planted at Fazenda Santa Eliza, the field station of the Instituto

Agron6mico de Campinas (IAC) in the state of Sao Paulo (latitude 22053'S)

a few miles north of the Tropic of Capricorn. These became the basis for

a vast succession of hybrids and backcrosses selected for adaptation to

the Brazilian tropics and subtropics over the next quarter century.

Santos-Neto (1955) deserves recognition for creating the first modern

grape hybrids in the tropics, for the tropics, with tropical (and

subtropical) germplasm.

While Fennell was away in the Caribbean, viticulturist Loren Stover

of the agricultural experiment station in Leesburg, central Florida, was

visiting a nearby farm when a field hand walked by eating what appeared

to be unripe green grapes. Stover (p.c. 1982) was surprised to discover

that the grapes were not only ripe and quite sweet, but also wild from a

large vine eventually classed as V. simpsoni. (25) It was named Pixiola

and used by him as the female parent of the first hybrid selection

produced and released by the state's adaptive grape breeding program, the

Lake Emerald (Stover, 1960).

Stover, who had no formal training in plant breeding, expanded his

hybridization to include other foundling native grapevines. His work laid

the foundation for the present program, expanded considerably under his

successor, geneticist John Mortensen (Mortensen, 1971, 1980). The

development of adapted hybrid varieties for many uses has created a

diverse viticultural industry in Florida (Bates, et al., 1980).

In conclusion, it can be affirmed that the evidence articulated in

this chapter demonstrates the plausible evolution of adaptive grape

breeding in Florida from the Spanish mission settlements to the modern

state experiment station in Leesburg. However, the sequential pathway is

more often devious than direct, with many ramifications. The explanatory

scheme that is here presented is in the nature of a road map of a

territory that has considerable terra incognita.

On the basis of the archaeobotanical evidence, for example, the

Sauer grape theory of aboriginal cultivars cannot be decisively confirmed,

only elevated to a more sophisticated level of conjecture. Then also,

there are the apparent dead-ends of phylogenetic discontinuity. The

antebellum wine grapes Black Spanish and Herbemont, of presumptively

mission origin, were long eschewed as adaptive progenitors in Florida

(Mortensen, et al., 1977), probably because of a remnant prohibitionism

(Watlington-Linares, 1984).


On the other hand, the above varieties were used in hybridization

by Munson and by later breeders in France. Some of their descendants have

returned to Florida where they have become the parents of more recent wine

grape hybrids (Mortensen, 1971; Mortensen and Andrews, 1981). Fennell's

V. gqas was lost for many years. Recovered in the early 1980s (Fennell,

p.c. 1984), it may yet be used in breeding new varieties. Simpson's grape

has been used to a limited extent in the Leesburg program (Mortensen, p.c.


The main contribution of the Florida mission grapes has been

ideographic. Their very existence and functional utility has been

responsible for the widespread adoption of adaptive breeding, both as a

dynamic grassroots tradition and as a practical scientific approach to

viticultural adaptation. Although Floridian grape cultivars have been

disseminated world-wide, few have proven adapted outside the narrow

latitudinal limits of the peninsula. However, as will be appreciated more

fully in the following chapters, Florida has played a key role in the

stimulus diffusion of adaptive hybridization to the New World tropics.

Nonetheless, the process has been hindered by the lack of adaptedness of

Florida cultivars to relatively short tropical daylengths.


1. These researchers have demonstrated that geographical and
archaeological series of grape seeds can be used to detect origin
and diffusion of somatic traits reflecting intra and interspecific
hybridization (See also: Olmo, 1942; Negral, 1957).

2. Subsequently, a second corridor was extended westward across the
peninsula, incorporating the peoples of Timucua and Apalache. At
its height the Spanish mission sphere embraced some forty principal
village communities (Gannon, 1965).

3. However, the location on the Atlantic Coast of Santa Elena and the
other Sea Island settlements provided long term protection from
lethal freeze damage for tender Mediterranean fruits (See "South
Carolina" and "Georgia" in Weather Atlas of The United States,
4. According to Marvin T. Smith (p.c. 1984), the upper branch appears
to have been considered the main Altamaha by natives of the area at
the time of De Soto's passage in the spring of 1540 (See also:
Hudson et al., 1984). Covington (1964) mentions a group of
Apalaches resettled on the Oconee until 1715.

5. It has been noted that the Creek were dedicated horticulturists who
insisted on planting and cultivating orchards even as they were
being dispossessed and forced to rely on less sedentary subsistence
strategies such as fishing, gathering and herding (Fairbanks, 1952;
Mason, 1963; Covington, 1964).

6. Woodson refers to the archipelagic condition of peninsular Florida
(Central Florida he calls "Orange Island") during the Pleistocene
interglacial periods.

7. The practice was widespread from the Late Archaic period (3,500 to
4,500 BP) on, as indicated by the abundant presence of charred seeds
in the archaeological record (Yarnell, 1976; Watson, 1980; Ford,
8. The species are: V. munsoniana, V. rotundifolia, V. aestivalis, V.
vulpina, and V. shuttleworthi (Rogers and Mortensen, 1979). A
number of seeds suggested intermediacy between vulpina and
aestivalis. Grapevines of phenotypically hybrid appearance have
been observed by the researcher as comprising perhaps 10% of the
wild Vitis population in some areas. This is in agreement with the
experience of viticultural botanists in other parts of the U.S.
southeast over the years (Bartram, 1804; Rafinesque, 1830;
Engelmann, 1883; Bailey, 1948; Munson, 1909; Fennell, 1945; Rives,
1963; Olmo, 1976; Duncan, 1975).

9. Sources included the University of Florida Herbarium, the living
collection of Vitis forms at the Leesburg Agricultural Research
Center (IFAS), the U.S. National Herbarium of the Smithsonian
Institution, the University of Tennessee Museum, the American Museum
of Natural History, Florida State University (Margaret Scarry), and
documentary sources featuring illustrations of grape seeds.

10. In reply to a classified advertisement placed in the July 15, 1983
edition of Florida Market Bulletin, several south central Florida
residents sent descriptions and samples of hybrid-like foundlings,
suggestive of both V. shuttleworthi and V. aestivalis.

11. Viala noted many similarities of "simpsoni" and coriacea. In
particular, that the very short beaked seeds of the first were
indistinguishable from those of certain forms of the latter. He
concluded that hybridization between diverse forms must be common
in Florida.

12. Slimpson's Grape according to Bailey, equivalent to Munson's revised
V. simpsoni.

13. All seeds of the three samples were measured by Lee A. Newsom,
Department of Anthropology, University of Florida, Gainesville,
using a "Manostat" dial type 6921 caliper.

14. Coffee, for example, loses about 18% of its weight and presumably
reduces its proportions accordingly when roasted. See also, Shea
and Crites (1980), Minnis (1981).

15. Considerable shrinkage is assumed to have occurred in the herbarium
sample of V. gigas collected by Fennell in 1938, near Roseland,
Brevard County, Florida.

16. Fernald found a direct correlation between seed and berry size which
justified his separation of VL from aestivalis. Abandoned
cultivars, on the other hand, would presumably generate populations
of wild descendants in which their horticultural attributes would
tend to be genetically dispersed.

17. Very high soluble solids, mainly sugar, (over 20 Brix) has been
noted by this observer and others in some Florida forms of V.
aestivalis, in contrast to other local species, but in accordance
with V. vinifera.

18. That Bartram was puzzled is surprising. He has long been considered
a competent botanist and ampelographer. His father John Bartram
organized the first living collection of North American grapes in
his Philadelphia botanical garden. William authored a pioneer
American ampelography (Bartram, 1804).

19. Following Chapman et al. (1982), the Southeastern cultural periods
for prehistorical archaeological purposes is, in part, as follows:
Middle Archaic, 5,000 to 8,000 BP; Late Archaic, 2,500 to 4,500 BP;
Woodland, 1,000 to 2,000 BP; Mississippian, Contact (500 BP to 1,000

20. It has been proposed that the spread of the bottle gourd (Lagenaria)
in the Southeast is a likely indicator of an ideological (religious
and political) movement or "Great Tradition" that may have led to
the adoption of other plants for shamanist rather than subsistence
purposes (Hall, 1977).

In the so-called "squash and gourd" zone at Phillips Spring,
Missouri, uncarbonized grape seeds (preserved by saturation)
outnumbered seeds of the early cultigens by six to one (Kay et al.,

21. Early Woodland (ca 2,000 BP) grape seeds have been found in human
paleofeces from dry caves in Kentucky (Yarnell, 1969). The context
suggests they were ingested in preparation for death.

22. The ephemeral commercial success of several Munson hybrids in
central and west Florida led Charles Demko (of Altoona) to begin
breeding native peninsular grapes with American cultivars in 1927
(Mortensen, 1971).

23. The daylength shortening effect of tolda is enhanced by the location
of Turrialba. Nestled in the eastern piedmont of the Cordillera
Central, evening falls early in the rainy season as cumulo-nimbus
clouds pile against the mountains, thus "advancing" the westerly
setting of the sun.

24. This researcher observed in 1971 and subsequent visits to Campinas
that part of the Turrialba material in the IAC collection was
mislabeled. Two were species supposedly used by Fennell He claims
(p.c. 1984) he never took V. jgs or V. smalliana to Costa Rica.

25. An expedient that conveniently avoids the problem of origin of this
exceptional native clone with horticultural attributes.


Venezuela provides a still unfolding epitome of a modern tropical

viticulture that is emerging from the largely empirical development of

traditional adaptive techniques. Although there are elements of

historical continuity from the early colonial period, it is largely a

recent phenomenon, arising from the geographic interface of diverse

cultural and geo-environmental factors during the latter part of the 20th

century. The process has generated a modest fund of documentary data and

direct sources of first-hand testimony that make possible the following

examination. Most of the information for this chapter was obtained in the

course of two visits to Venezuela, in April 1988 and in November 1989.

Before World War II grapevines were grown sporadically in gardens

and small vineyards throughout much of Venezuela between latitudes 8N and

120N (Eguiraun, 1945; Araque, 1969). After the war, a wave of immigrants

from Mediterranean Europe sparked an upsurge in planting and in public

interest concerning the possibility of viticulture as a viable agri-

industrial enterprise. In 1961, the first agricultural census to feature

grapes recorded only 4.75 hectares (MAC, 1970). Although probably

underreported, the figure is in stark contrast with the roughly 300

hectares reported for 1969, eight years later (Ibid.).

By 1975, the number had doubled to 600 ha. However, the spectacular

growth of the 1960s and 1970s was not distributed evenly among all the



geographic areas in which people were striving to establish vineyards.

This is made clear in Table 4, where grapevine areas are compared by state

between 1969 and 1975.

Table 4. Vineyard area in Venezuela, By State, 1969

1969 1975
Ha. % Ha. %

tegui (unlisted) 38.5 6.6

a 59 19.8 91 15.4

obo 6 2 6 1

21 7 61 10

a 7 2.3 3.5 .6

da 4 1.3 (unlisted)

11.5 3.8 5 .9

ra 11 3.7 4.5 .7

llo 17 5.7 (unlisted)

162 54.3 380 64.5

uela 298.5 100 589.5 100

e: MAC, 1969; and Ramirez-Soto, 1976.

and 1975

% Change








Mi ran







The table shows that ten states had vineyards during the post-war "grape

rush." At the end of the period, however, plantings had declined or

disappeared in all but four states.

Only Zulia, Lara, Aragua, and Anzoategui (in descending order, and

from west to east) had experienced a "grape boom" by 1975. By 1980 total

hectareage for Venezuela had again doubled, to 1,200 ha. (Bautista and

Vargas, 1980). Half of the area, 600 ha, was planted in the districts of








Mara, Maracaibo and Urdaneta, in the immediate hinterland of the city of

Maracaibo, capital of the westernmost Venezuelan state of Zulia. The tide

receded in the early 1980s to about 1,000 ha in Zulia (Corzo, 1987). Lara

maintained a lagging second place with more or less 200 ha (20%) in

grapevines spread across five districts: Moran (El Tocuyo), Urdaneta

(Siquisique), Torres (Carora), Jimenez (Quibor), and Palavecino

(Tarabana), (Instituto de la Uva, 1988).

The two states, Zulia (capital Maracaibo) and Lara (capital

Barquisimeto), where viticulture has been relatively successful have in

common climatic conditions that assure maximum insolation for most of the

year (Figure 3). The traditional technique of adaptive insolation

optimization implicit in the selection of both regions by viticulturists

has been covered in detail in Chapter 2 and will only be dealt with

briefly in this chapter. Instead the following analysis compares the

development of the related techniques of adaptive pruning and adaptive


There are important differences as well as similarities between the

neighboring regions that imply alternative developmental constraints and

opportunities for viticulture. In both areas, the best land for vineyards

consists of nearly level alluvial terraces with well-drained, sandy

profiles at least one meter in depth (Vargas, p.c. 1989). However, the

so-called Maracaibo highland (altiplanicie) is really a peneplain raised

no more than fifty meters above its coastal periphery (Araujo, p.c. 1988).

In contrast, the inland fault valley depressions of Lara are elevated from

300 m at the foot of the Baragua escarpment in the north, to 700 m at the

edge of the Andes in the south (Guevara and Guevara, 1983).



0 20 40
.. ... o I Kilometer

Figure 3. Semiarid areas of western Venezuela, and approximate extent of

April-June and September-November tolda (6/8ths cloud cover).

Soure: After Guevara-Diaz, 1985; and MINIDEFENSA, 1984.


The Beginning

During the World War II years the importation of table grapes to

Venezuela was sharply curtailed, and cottage-scale growers of

comparatively poor quality fruit had a windfall. At the end of the war,

Italian and other South European immigrants settled in the hot, dry

coastal plain around Maracaibo, a landscape reminiscent of the

Mediterranean. There they became enthused by the prospect of a lucrative

crop that was familiar. Extensive varietal collections of Old World

grapes (V. vinifera) were introduced from Italy and elsewhere in an all-

out effort to find cultivars that would adapt to local conditions (Olmo,

1968; Araque, 1969; Melendez and Garassini, 1973).

By the early 1960s a handful of imported varieties had proven

reasonably productive as well as commercially attractive. The selected

cultivars could be pruned at any time of the year, and coaxed into

yielding two to three harvests yearly (Fregoni, 1977). However, the

foreign grapes had not been bred to withstand periodic spells of rainy

weather and high temperatures combined with high atmospheric humidity.

Such conditions, endemic to even the driest areas of Venezuela, brought

on mildews and other fungi that would disfigure fruit bunches and weaken

the vines by defoliation.

Thus, when commercial harvesting began in 1964, a promising market

for petroleum-derived fungicides, pesticides, growth regulators and

fertilizers began to unfold. Vineyards were included in the financial

credit program of the government's National Plan for Fructiculture


(FONDFRU, 1975). In 1965, FUSAGRI, the Shell Foundation for Agricultural

Services, began varietal trials at its experiment station in Coro (Falcon


As vineyard hectares multiplied, there seems to have been misgivings

in official circles concerning long term viability of the immigrant

temperate zone crop. The prevailing view among formally trained

agronomists was Winkler's (1962) authoritative dictum that without an

adequate low temperature period of rest V. vinifera vines in the tropics

could only be expected to produce small yields of poor quality fruit.

There was pressure also from the enduring viticultural community farther

inland, which began to feel left out of the incipient boom. FUDECO, the

government Foundation for Development of the West-Central Region, decided

to bring in an outside expert.

The choice was Dr. Harold Olmo (University of California, Davis),

renowned authority on grape genetics and geography. Olmo's 1968 survey

of Lara, Zulia, and neighboring areas identified prospective locations for

viticulture based on a subjective evaluation of geo-environmental

characteristics. He rejected the temperate zone tenet of "heat summation"

as inappropriate, and by implication laid to rest concern about the

chilling requirement, disregarding it altogether. Olmo also pointed the

way to a more scientific approach to adaptive pruning and adaptive


The Olmo report was officially presented at the First Symposium on

Production and Industrialization of the Grape in Venezuela (Maracaibo,

1969). In 1970, the grape growers of Zulia organized formally and

petitioned the government for protective legislation against imports,


which was enacted in 1971 (Millan, 1975). In 1973, FUSAGRI started a

broad program of research and technical assistance in viticulture, with

funding from CORPOZULIA, the state economic development agency.

Lara was not to be left behind. In 1974, an Instituto de la Uva

was established at the state university in Barquisimeto, capital of Lara.

A second viticultural symposium was sponsored by FONDEFRU and held in

Barquisimeto early that year. The agenda covered a comprehensive

assessment of the prospects for viticulture as an authentic agricultural

industry for Venezuela. Perhaps the most influential reports were the

supportive overviews of two additional outside experts, Professor Pierre

Galet (Montpellier, France), and Professor Luis Hidalgo (Madrid, Spain).

These led the way for visits by still other consultants: Alleweldt (1975,

Germany), Fregoni (1977, Italy), and Lider (1978, California). The door

was open for transferral of state-of-the-art technology from Europe, and

to a lesser extent from the United States.

Finally, in 1977, a Centro de Desarrollo de Viticultura Tropical

(Centro Viticola) was founded in Mara, near Maracaibo. The non-profit

foundation was jointly sponsored by CORPOZULIA, FUSAGRI, and AVEZ

(Association of Zulia Viticulturists). The Center sophisticated and

broadened the range of research and extension activities that had been

initiated by FUSAGRI.

By the turn of the decade, a number of young Venezuelan agronomists

were undertaking academic training in viticulture and allied subjects such

as enology in Argentina, California, Spain and France, as well as

Venezuela. In the 1980s a native corps of technicians was in the

forefront of research on adaptive tropical viticulture.


The Pruning Calendar

The pruning of grapevines in the tropics pursues adaptive goals

analogous to those at higher latitudes. Pruning is done to train vines

to a manageable framework, to optimize productivity, and to coordinate

critical stages in the fruiting cycle with adequate climatic conditions.

On the other hand, procedures introduced from higher latitudes and applied

without modification are often ineffective, and at worse counteradaptive

in the tropics (See Chapter 2).

Therefore, Venezuelan viticulturists have had to develop special

procedures for adaptive management of their immigrant crop. For example,

while long or cane pruning is productive at higher latitudes, only short,

or spur, pruning can deal with the problem of apical dominance and

consequent irregular, weaker budbreak of "unrested" vines under tropical

conditions (Bautista and Vargas, 1980). On the other hand, the more or

less continuously active vegetative state of adapted V. vinifera cultivars

at ca. latitude 10N allows training of the vine to a mature bearing

structure within a year, in contrast to the three or four years required

in places with discrete and shorter growing seasons (Simancas, 1988;

Vargas, p.c. 1989).

However, realization that pruning rather than repose (with or

without chilling) would renew the fruiting cycle marked the discovery of

tropical viticulture in the colonial period and its recurrent rediscovery

by immigrant growers and modern researchers (Bautista and Vargas, 1980).

For it is the prospect of two or more harvests yearly that has heartened

grape growers faced with the disappointing productivity of their imported



The crucial question of when to prune arises because of the

demanding climatic requisites of V. vinifera grapevines. Having evolved

originally in the arid Middle East (See Chapter 2), the cultigen generally

requires a very dry growing season, uninterrupted by rain or high

humidity. Ideal conditions are rarely encountered, even in its European

range, where its perimeter has shifted unceasingly over the centuries.

Nonetheless, in the Mediterranean basin a virtually rainless growing

season is more or less assured (Critchfield, 1974). Not so in the

seemingly dry environments of the Venezuelan tropics. According to

Guevara-Diaz (1985), the viticultural areas of Zulia and Lara (Figure 3)

as well as a promising development in the eastern state of Anzoategui, are

in regions climatically typified as "semiarid," or "BS" in Koppen's

classification. Tropical semiarid climates are characterized by

relatively high levels of insolation, hence high diurnal temperatures, and

evapotranspiration in excess over precipitation. Rainfall can be very

erratic, so that annual averages are of little help in delimiting

viticultural zones.

Moreover, relatively high levels of atmospheric humidity prevail.

In the semiarid areas mean relative humidity ranges from 70% to 76%

(Guevara-Diaz, Ibid.). (1) Only the widespread incidence of the trade

winds moderates diurnal temperature and keeps relative humidity around a

diurnal mean of 70% (Vargas, p.c. 1989). At night, when the trade wind

ceases and temperature drops, relative humidity in the semiarid regions

normally exceeds 80% (Vargas, Guevara-Diaz, Idem.). Although there are

wide varietal differences in tolerance to atmospheric humidity within V.

vinifera, the better adapted are precariously susceptible to breakdown


under environmental stress. When atmospheric moisture approaches the dew

point, all parts of the actively growing grapevine are subject to

infestation by various fungus maladies.

Mildews, for example, attack the leaves, progressively defoliating

and weakening the vine. However, damage can usually be allayed by timely

spraying with fungicides. Equally susceptible, and rather more difficult

to protect, are the fruiting clusters which are especially vulnerable

during flowering and fruit set, and again during ripening.(2)

Consequently, deciding when to prune requires detailed knowledge of local

seasonal rainfall patterns and of the phenology of the varieties that are

cultivated. The study of both subjects has become a central concern of

adaptive viticulture in Venezuela.

Overall, there are two major seasonal patterns of rainfall

distribution in Venezuela (Guevara-Diaz, Ibid.). A unimodal pattern with

maxima in June, July or August prevails in most of the country. Toward

the Andes in the west the pattern becomes bimodal with maxima in April or

May and in October. However, oceanic and topographic influences result

in intricate transitional and local patterns. In general, it is drier in

the coastal zone and inland rain shadow valleys, and wetter in the

northeast and higher elevations to the south and west.

In the first Venezuelan pruning manual, Eguiraun observed "an

incomplete recess" in grapevine vegetative activity during December and

January in some areas, and a "slight recess" in July and August, "as if

there were two vegetative cycles in a year" (Eguiraun, 1945: p. 6). He

then theorized that vine repose could be obtained either with low

temperatures or by withholding water, as was done in Belgian hothouses for


producing out of season table grapes. The problem in Venezuela, he

concluded, was to find varieties and pruning techniques that would yield

a crop within dry periods.

However, Eguiraun made no specific recommendation concerning when

to prune. Possibly he was constrained by his acceptance of the

theoretical need for a rest period by either chilling or drought. He did

not perceive the slowdown in vegetation as a response to shorter

daylength, both during the drier and cooler winter solstitial period and

again during the cloud covered summer rainfall climax. Apparently

attributing growth recesses to the lower temperatures that accompany the

increase in cloudiness, he rather expressed concern over the heat

summation required to complete the crop cycle.

Eguiraun carried out much of his work as a government horticulturist

in a coastal highland experiment station near Caracas (ca. 900 m ASL)

during the late 1930s and early 1940s. At the time many growers still

accepted temperate climate verities concerning the putative requirement

of cool weather. It is said that modern viticulture in Venezuela began

in 1938 when a home grown practitioner, Fortunato Gil, gave up trying to

grow grapes in the cool highland of Humocaro Alto (Lara) and established

a prize winning vineyard in the semiarid piedmont valley of Humocaro Bajo

(Araque, 1969; Vargas, p.c. 1989).

At any rate, in the early years the decision of when to prune

appears to have been highly subjective, based on each grower's

understanding of grapevine interaction with the local climate (Olmo,

1968). By the late 1960s regional patterns began to emerge. Araque

(1969) reported that in Zulia there were two pruning periods, one in


September to October for a December to January vintage, and another in

April for a July harvest. For Lara there was a single pruning in the

period from October to December for harvesting from January to April. In

the Andean state of Tachira on the Colombian border, and the north central

state of Aragua (just south of Caracas) pruning was done in July for a

vintage in December.

Interestingly, a two-crop pattern was mentioned only for Zulia,

which was already in the lead of vineyard expansion. The first complete

viticultural handbook, compiled by the growers of Zulia (Rojnic et al.,

1972) did not specify pruning dates but stated somewhat vaguely that

pruning should be programmed so that the ripening period would not

coincide with the rainy season of October-November. The first official

pruning manual published in Lara (Melendez, 1978) explicitly recommended

pruning toward the end of the rainy period. This appears to have been the

general rule of thumb (Raniery, 1969).

Subsequently, Galet (1973) coincided with Araque on the first

pruning period for Zulia (September-October), but assigned the second to

February and March rather than April. He also differed concerning

Tachira, where he found two prunings also, in May and January. He listed

the neighboring Andean states of Merida with pruning in March-April and

August-October, and Trujillo with pruning every four months beginning in

April. With a certain exasperation Galet added, "and even all year

around: in January, May, June, August, September, October, November, and

December" (Galet, 1973: p. 6).

Galet's report is one of the earliest to mention a phenological

event, blooming, as occurring fifteen to thirty days after pruning,


implicitly during dry weather. There may have been an error in

transcription, since it is budbreak which takes place roughly at that time

(Bautista and Vargas, 1981). Hidalgo (1974) offered a more explicit

statement of the need to correlate pruning with the phenological cycle.

Pruning should be done toward the end of the rainy season, he recommended.

In variety selection, he added, the duration of its fruiting cycle from

pruning to prospective date of harvest should be taken into consideration.

Long cycle varieties, requiring four or more months (120 or more days)

should be discarded in favor of short cycle varieties (ca. 90 days) that

would allow two or more crops per year.

Hidalgo proposed that viticultural sites in Venezuela be evaluated

and correlated with appropriate varieties by means of the "heliothermic

index" (HI). The HI is a European invention derived from Winkler's (1938,

1962) "heat summation" by Branas (et al., 1946) who added daylength as a

variable for measuring the calendar duration of appropriate (i.e. warm

and sunny) conditions for the fruiting cycle (See also: Santibafiez et

al., 1986). The formula for the HI is XH x 10-6, where X represents mean

degrees of effective heat per month, based on daily temperature over 10C

(50F), the threshold for vegetative activity in V. vinifera. H

represents the summation of hours of effective insolation per month. The

product is reduced to a manageable index on multiplication by 10-6.

The HI formula does not take into account the function of daylength

as a phenological regulator. Winkler, for example, observed that although

grapes in California would normally bloom when the mean daily temperature

reached 68F (20C), "in areas where a mean of 68F is not reached,

factors such as length of day seem to influence the time of blooming"


(Winkler, 1962: p. 106). Branas (1974) also was somewhat aware of

photoperiodicity in grapes. He noted that leaves became very large close

to the polar limits of cultivation, but were rather small in the


Regarding the HI, Branas had offered the caveat that in the lower

latitudes where ambient temperature is always above 10"C the HI formula

"loses all meaning" (Branas, 1974: p. 351). Nonetheless, to the nascent

research establishment Hidalgo's well articulated positivist prescription

must have seemed at once pragmatic and authoritatively "scientific."

Despite its flaws, the HI would become the cornerstone of adaptive

viticulture strategy in Venezuela in the 1980s. The pruning calendar

would evolve accordingly, as the principal instrument to implement that


Nineteen seventy five marks a watershed of institutionalization for

Venezuelan viticulture. Plans for research and development were being

drawn up and priorities established within a coalescing framework of

public and private organizations sharing the interest. Expert European

opinion corroborating Olmo's 1968 assessment and the Second Symposium

(1974) gave impetus to the process.

European consultants, Galet (1973), Hidalgo (1974), and Alleweldt

(1975), agreed on the priority of expanding the narrow cultivar base with

quarantined introduction of promising V. vinifera varieties. Hidalgo

thought that those varieties that did well in southern Europe would be

most likely to adapt. Galet suggested premium wine clones from France to

initiate diversification away from table grapes. All shared the long

standing officially sanctioned European aversion for North American


species hybrids, except as rootstocks.(4) Most echoed Olmo's (1968)

warning against importing such hybrids from the southeastern United States

for fear of introducing Pearce's disease and other maladies endemic to a

region with a growing season as hot and humid as that of Venezuela.

With existing humid environment hybrids eschewed, accurate

determination of pruning calendars became crucial, along with the

evaluation of V. vinifera selections in promising locations such as those

identified earlier by Olmo. Perhaps because of the geo-environmental

diversity of the viticultural areas of Lara and their relative

underdevelopment vis-a-vis the Maracaibo area, the new Grape Institute

led the way in studies of the measurement of grape phenology in the

context of local geographic conditions (Vargas and Freitez, 1982;

Bautista, 1987).

Economic concerns were foremost. According to a report by Millan

(1975), the state of Lara had decreased its share of the grape crop from

11.6% in 1969 to 1.3% in 1972. It had dropped from third place in

production to a poor fourth, almost tied with Trujillo. Yields had

declined from 3.4 metric tons per hectare to 2.96 t/ha as the national

average, between 1970 and 1972.(5) Imports of table grapes supplied over

85% of the market in 1972 and were rising despite restrictions.

Importation of concentrated must for winemaking had almost doubled during

the same two years.

In 1976, Professor Luis Garassini, Director of the Instituto de la

Uva, cited Millan's report, and added Hidalgo's (1974) warning that local

production of table grapes (mainly in Zulia) could more than cover the

local market within a very few years (Garassini, 1976). He reiterated


official concern that low yields and high production costs threatened the

long term viability of viticulture as an economic enterprise.

Following the advice of Galet and Hidalgo, Garassini proposed that

the Institute focus on research toward development of a wine industry as

a promising alternative to table grapes. Grape varieties should be

introduced and evaluated, he argued, in terms of their potential for wine

making. Stressing the need to increase funding for such research, he

pointed to the lack of adequately trained technicians and the prevalence

of viticultural practices inappropriate for Venezuelan environmental


Two years later, in 1978, an Institute faculty member, agronomist

Guillermo Vargas, submitted his thesis for a licentiate degree in

viticulture and enology from the Polytechnic University of Madrid, Spain,

where he studied under Hidalgo. The Vargas thesis developed a model

application of the HI to eight scattered viticultural zones in the state

of Lara, for comparative evaluation and correlation with European grape

varieties of known HI values. Vargas' work marked the beginning of

serious studies of climate and grape phenology in Venezuela. It was to

be highly influential in determining the dominant research trend of the

1980s in tropical viticulture. However, this early thesis dealt only with

table grapes.

Vargas' model can be summarily described as follows. All

prospective viticultural zones of Lara state and the capital Barquisimeto

were pinpointed on an outline map. Mean monthly rainfall for each

location was presented in bar chart form accompanied by data on latitude,

altitude and total precipitation. A thin line was drawn across each chart


at the 100 mm (approximately 4 inches) level, indicating the critical

threshold at which development of the V. vinifera fruiting cycle becomes

hazardous. Curiously, this empirical rule of thumb had been independently

arrived at by this researcher after many years of geographical

observations in Puerto Rico (See Chapter 5).

Vargas was careful to prequalify his eight prospective zones "with

viticultural vocation" according to the following criteria:

1. Mean annual rainfall not over 650 mm [25.6 in.];
2. Elevation not over 662 m ASL;
3. Dry periods of no less than four months duration;
4. Zones without limitations for grape cultivation.
(Vargas, 1978: p. 8).

Essentially, he is offering an empirical description of proven locations

within the state of Lara. However, his modification of Branas' HI is

innovative. He assumes that in the tropics pruning is equivalent to the

high latitude 10C (50'F) growing temperature baseline from which

effective heat (i.e., insolation) is accumulated.

The Vargas thesis proceeds as follows. HI formula data was

tabulated monthly for each zone, and two starting (pruning) dates assumed,

the premise being that two crops could be accommodated per year. In each

case, the first of December was chosen to initiate the first cycle. The

second cycle was initiated the first day of July in half of the locations

(the easternmost), and the first day of June in the other half (the

westernmost). The start of the cycles correlates in some locations with

the last month of a rainy season, and in others with the first dry month

thereafter. The end of the cycles coincides in every case with the end

of a dry period, April after pruning in December; September, October, or

November after pruning in June or July.

To complete his model, Vargas simply "fits" the zonal HIs with those

of grape varieties classified in Europe as early, midseason and late, to

thereby confirm Hidalgo's prediction that early to midseason (so-called

"first season") varieties could be double cropped in the preselected

viticultural zones. His conclusions include the admonition that during

periods of high rainfall the vines should be kept in a "repose"

characterized by cropless vegetation, during which new foliage is formed

and nutrient reserves are accumulated. Preventive control of fungi is

required (42 to 58 days depending on the zone) to avoid premature

defoliation and initiation of a new cycle while undesirable conditions


The assumption that reserves are accumulated in the vine during the

rainy season is in line with Eguiraun's (1945) "slight recess in

vegetation", previously cited, and with the popular designation of such

periods as "winter." However, it contradicts the theory initially

proposed by outside experts of continuous and exhaustive vine growth under

tropical conditions. The overcast or tolda produced during the rainy

season most likely shortens photoinductive daylength below the twelve hour

threshold, signaling the vine to stop growing and commence the

accumulation of reserves (See Chapter 2). Thus, the traditional allowance

for a rest period in the pruning calendar becomes functionally adaptive.

In a final conclusion Vargas advised that his theoretical exercise

should be the object of experimental field trials for verification, and

that other (geo-ecological) factors affecting viticulture be related to

the HI. Clues pointing to daylength (as a regulator of phenology) as one

of those factors continued to appear. Indeed, while Vargas was studying


in Madrid, an important evaluation of Venezuelan viticulture by the

Italian researcher Fregoni featured the observation that:

The difficulty of adaptation of Vitis vinifera in the tropics
is linked to photoperiodism; indeed, it may generally be
considered a long day species. A few varieties, however, can
adapt to short day areas (Fregoni, 1977: p. 27).

This comment by Fregoni appears to have gone unnoticed, probably

because daylength per se had not been recognized as a meaningful parameter

by Venezuelan researchers. However, a pioneer experimental study compared

varietal productivity during four successive calendar semester cycles

initiated by pruning in January and July (Bautista, 1975). Eight

relatively well adapted cultivars (featuring at least two reputed V.

vinifera-caribaea hybrids) responded similarly with respect to seasonal

productivity. Irrespective of varietal differences, all were considerably

more fertile (floriferous) after pruning in January than after pruning in


Bautista's results are consistent with the findings of previous work

(notably Kobayashi et al., 1966; Buttrose, 1969a, 1974) reported in

Chapter 2. That is, grapevine buds formed during relatively long days

(i.e., over 12 hours) produce more fertile canes and more flower clusters

per cane than those formed during relatively short days (i.e., under 12

hours). In other words, in Venezuela also, buds formed during the long

days after pruning in July are more productive than those formed during

the short days after pruning in January.

The data available from Bautista's (1975) study, although severely

limited (6), is suggestive of a measure that might be used to compare

varietal sensitivity to daylength in terms of fruitfulness. Two of his

tabulations are useful. The first compares the mean number of fertile

shoots (canes) developed by variety after pruning each semester. The

second compares mean number of flower clusters developed by variety for

each semester. If the difference between short and long day semester

yields of each variety in both tabulations are multiplied, the result is

an absolute indicator of "daylength inducted productivity" (DIP).

A comparable index can be obtained by using the integer one as a

common dividend and each DIP as divisors. The resulting "daylength

sensitivity index" (DSI) reflects the degree to which productivity is

dependent on daylength above the mean minimum at the latitude (as modified

by altitude) where the vines were grown. The results are summarized in

Table 5. Interpretation of Table 5 is as follows. The native hybrid

Villanueva (according to Olmo, 1968, an apparent second generation hybrid

of V. vinifera and V. caribaea) is the most sensitive of the tested

cultivars, having the lowest DSI. In second place is Muscat Hamburg, a

traditional European "forcing" variety, only slightly more tolerant of

relatively short daylengths. Another traditional hothouse variety, A.

Lavallee (also known as Ribier) is third, and Italia, also a "boutique"

quality table grape being somewhat less short day intolerant comes fourth.

Unexpectedly tied in fifth place are Cardinal, a very short cycle

European type, and the native Criolla Negra hybrid. Because the absolute

productivity of the latter is surpassed by Villanueva, it would seem a

contradiction that its productivity is less limited by suboptimal

daylength. Nonetheless, Bautista was at a loss to explain why Criolla was

virtually infertile during the July semester, after pruning in January.

Table 5. Evaluation of Fertility Differences in Grape Cultivars,
by Semester (Merida, Venezuela: lat. 830N)

Cultivar No. Fertile Canes Diff. No. Clusters/Cane Diff. DIP DSI
Dates: 7-11-72 1-6-73 (2-1) 7-11-72 1-6-73 (5-4) (3x6) ('1'/7)


Muscat Hamburg

A. Lavallee



Criolla Negra



































































Source: Bautista, 1975; additional computation by the

Note: DIP is "daylength inducted productivity;" DSI


is "daylength sensitivity index."


He concluded the variety was suitable only for annual cycle pruning. A

close sixth is Violeta (or Victoria), possibly also a native second

generation backcross hybrid, and a heavy bearer at lower elevation in Lara

(Diaz and Aguero, 1975). Last is Mustosa, similarly a heavy cropper in

Lara (Ibid.), but which performed irregularly at the trial site in Merida.

Bautista concluded that the first three varieties, Villanueva,

Muscat Hamburg and A. Lavallee, are the best adapted of those tested. He

also noted that the semester initiated by pruning in January is more

productive than the semester initiated in July. The explanation is, of

course, that buds fruiting after pruning in January were formed during the

relatively longer days of summer. Whether Villanueva would be much more

productive at higher latitudes remains to be determined.

A position paper by Bautista and Vargas (1980) summarized the status

of Venezuelan viticultural science at the turn of the decade. The infant

local research establishment had by then been inserted in the

informational network linking similar organizations world-wide.

Concurrently, environmental limitations to adaptation of viticulture in

the tropics had been reduced to rainfall, and the need to fill the heat-

insolation requirement of the heliothermic index (HI). Henceforth,

official viticultural research in Venezuela would conform by and large to

the European mainstream of applied viticultural theory.

Following the path initially proposed by Hidalgo (1974), adaptive

research in the 1980s would emphasize massive testing of imported

varieties for appropriate "fit" to specific local heliothermic
"microclimates." The vines would be mainly V. vinifera selections

introduced from "safe" (certified disease-free) sources.(7) On the other


hand, because correlation of the fruiting cycle with local weather is

critical, rainfall and eventually other climatic data would be recorded

more systematically.

Studies which, in fact, measured daylength controlled responses were

engaged as necessary evaluation of physiological differences between

European varieties in the tropics. For example, Bautista and Vargas

(1980) cite pertinent authority in recognition that floral induction and

differentiation is completed within newly formed buds of an actively

growing grapevine shoot (cane) by the time the currently expanding flower

clusters open (Lavee et al., 1967; Pratt and Coombe, 1978). They then

affirm, following Huglin (1958), that vine fertility varies according to

variety, in terms of the position of the buds on the cane, and more

ambiguously on the environment.

No mention was made of the equally pertinent fact that the number

of flower clusters "imprinted" in a formative bud is in direct relation

to photoinductive daylength (Kobayashi et al., 1966; Buttrose, 1969a,

1974). Subsequently, a report by the same researchers measuring the

"heliothermic requirements" of six cultivars, concluded interestingly

enough that:

The duration of the cycle and its subperiods are affected by
daylength. Cycles initiated in short days tend to be more
prolonged than those initiated in long days. Therefore, it
is considered that the [semestral] cycles of the same year are
not homologous (Bautista and Vargas, 1981: p. 19).

The 1981 report by Bautista and Vargas was the first detailed study

of grapevine phenology in the tropics. Measurement of the fruiting cycle

covered four subperiods initiated by semestral pruning: 1) budbreak,

2) bloom, 3) veraison (beginning of fruit coloration), and, 4) harvest


(maturity). In the conclusion cited above, no attempt was made to elicit

broader implications by correlating, for instance, with Bautista's (1975)

earlier finding concerning semestral differences in fertility.

Consequently, the influence of seasonal daylength on fruit bud formation

continued to be ignored.

It appears that semestral pruning at the solstitial extremes does

not follow closely traditional empirical practice in Venezuela. Rather,

it may be a convenient administrative abstraction analogous to the use of

controlled environment "growth cabinets" in substitution of actual

geographic conditions in the field (Buttrose, 1974). Recognition of the

connection between changing seasonal daylength and potential grapevine

fertility would presumably lead to experimentation with pruning cycles

initiated in anticipation of the equinoxes, in order to assure that fruit

bud formation would take place close to the twelve hour threshold.

Bautista and Vargas (1981) had, indeed, established that less than

a month (19 to 26 days) of optimum daylength from budbreak to bloom would

suffice. However, such scheduling would occasionally run afoul of the 100

mm (4 in) mean monthly rainfall barrier which continued to rule the

pruning calendar (Ibid.). The question might then arise whether there was

not a better adaptive strategy than adaptive pruning.

During the 1980s the prevailing adaptive strategy, based on pruning,

remained unchallenged. Certain modifications did occur, spurred by the

gradual shift in emphasis from table to wine grapes. By 1984, researchers

at the Grape Institute had begun to realize that environmental conditions

in Lara held the promise of a competitive advantage over Zulia, which had

then completely dominated table grape production with over 80% of the crop


(versus about 15% for Lara). An Institute report outlining guidelines for

viticultural development in the west-central region of Venezuela,

discussed for the first time the implications on grape quality of

nighttime temperatures averaging 10C (18F) lower than daytime means

(Vargas et al., 1984).

At the same time, it had long been known empirically to growers in

Lara that imported varieties adapted best if grafted on the vigorous

native hybrid Criolla Negra (Olmo, 1968; Bautista, 1985). In Zulia,

however, vines were imported already grafted on foreign rootstocks (Corzo,

1987). Eventually the same rootstock varieties were imported and

propagated locally (Gallardo, 1988). Only near the end of the decade did

Zulian researchers cautiously begin to graft on native hybrids (Mielzarek,

1987). On the other hand, by 1986 the Zulia Center for Tropical

Viticulture had taken the lead by planting the first fifty of 3,000

proposed hectares of wine grapes (Corzo, 1988).(8) Two years later a

model experimental winery was inaugurated at the Center. Meanwhile,

evaluation of wine grape varieties was being stepped up in Lara (Vargas

and Bautista, 1987a).

In 1987, a decade after Garassini's initial proposal, Vargas

proclaimed that the wines of highest quality in all of Venezuela could be

produced in the state of Lara (Vargas, 1987). He identified six arid

zones with mean annual rainfall under 700 mm (27.5 in) and two well

defined dry periods of no less than 130 days each (4.3 months), delimited

by two rainfall peaks, generally in May and October.(9) He pointed out


that heliothermic values were moderately low, that is, with diurnal

temperatures not so high as to undo metabolic synthesis and accumulation

of qualitative components of wine must.

Vargas clinched his argument with the observation that temperatures

in the viticultural areas of Lara rarely rise above 28C (ca. 83F) during

the day. At night the mean is always close to 19C (66.5F), a

difference, on average, of 9C (16.36F). Such optimal conditions for

development of a balanced sugar to acid ratio (Kliewer, 1981) were

compared "rhetorically" (i.e., without empirical data) with those of

unnamed areas where constantly high day and night temperatures cancel

metabolic gains through excessive respiration. Thus, both synthesis of

color and aromatics and their accumulation in the grapes are adversely

affected (Kliewer, 1968; Buttrose et al., 1971, and with specific

reference to Zulia, van Balen, 1987).

Shortly thereafter, Vargas' proposal found a sponsor. Polar, the

major Venezuelan brewery, and Martel, the great Bordeaux winery, organized

a winemaking joint venture for Lara. Vargas took leave of absence from

the Institute to undertake a research and demonstration project for a

Master of Science degree, under auspices of the incipient enterprise

(Vargas p.c., 1989). By late 1989 Vargas was completing the draft of his

thesis while on the job as general manager of Bodegas Pomar, C.A. in the

central Lara town of Carora. The recently completed $1 million plus

winery was preparing its first vintage for market.

One hundred hectares of choice French and Spanish wine grape

varieties grafted on Criolla Negra had recently begun production in the

firm's vineyard at nearby Altagracia. The viticultural and oenological


technology being used was state-of-the-art in terms of adaptation to the

local environment. Various wines tasted by this researcher were

indistinguishable from the French archetypes. Vargas and his associates

have proved that wine growing on the European model can succeed in

Venezuela, with adaptive pruning--and native rootstocks. Whether the new

industry will be as competitive as its French counterpart remains to be


The principal weakness in the Vargas model is that dry periods in

the semiarid areas of Lara are not as well-defined in terms of calendar

incidence of rainy periods, and thus as reliable as he suggests. Yearly

deviation of critical rainfall maxima tend to be "averaged out" of long

term means. Unexpected shifts in seasonal rainfall cycles can add to the

difficulty of prediction (Caviedes, 1981). Vargas makes no use of daily

records which would be helpful in more accurately plotting characteristic

tropical precipitation, occurring mainly as torrential downpours. Such

records may be helpful also in detecting gaLa, a fine drizzle accompanied

by tolda (overcast) that can last for days, even weeks, with devastating

effects on V. vinifera, yet have little impact on monthly rainfall totals.

Whereas daily rainfall records in Venezuela are difficult to obtain,

the Institute's experimental station in El Tocuyo has maintained monthly

totals since 1978 that suggest a conceptual flaw in the Vargas model.

Vargas' (1978) Madrid thesis includes a 1973 FUDECO report in the

bibliography which is presumably the source (unspecified) of the long term

mean monthly rainfall data used for his graphs. His conclusion concerning

El Tocuyo, where he worked since 1975, is only partly in agreement with

his graph for the same area (Figure 4). Both are at variance with data

from the records of the Institute for the ten year period 1978-1988 (Table


According to Vargas (1978) the first rainy season is from April to

June at El Tocuyo, with a peak in May. This is supported by Figure 4.

However, Table 6 shows that critical maxima have occurred mainly in April

during the past decade, twice in March and only once in May. The second

rainy season is said to include October and November, with a peak in

October, that according to his graph is substantially under the 100 mm (4

in) critical limit. However, his conclusion is that the ensuing dry

season begins December first. Table 6 indicates that rainfall maxima in

excess of the critical threshold have occurred as often (three times) in

September as in October. Only in the anomalous year of 1988 was there a

protracted rainy season that began in August and actually ended in

December. In 1980 also, there was a brief near-critical peak in December.

The reason for the discrepancies can be explained in part as

follows. If the winter solstice dry season generally ends in April,

pruning at the beginning of December would allow a full four months for

the fruiting cycle to be completed under relatively dry conditions.

Similarly, pruning in late April would allow roughly four months before

the start of the next rainy period in September. However, as Bautista and

Vargas (1981) discovered, a difference of one hour and seven minutes

between the shortest and longest days of the year results in a difference

of up to fourteen days (for A. Lavallee) in the length of the fruiting



1 0 0 .....................



Figure 4.

Feb Apr Jun Aug Oct Dec

Mean monthly rainfall in El Tocuyo, Lara, Venezuela.

Source: According to Vargas, 1978.

Table 6. Critical Maxima, Monthly Rainfall: El Tocuyo (Lara), Venezuela, 1978-1988

Month* 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 Mean


Mar. 91.5 91.5 91.5
(3.6) (3.6) (3.6)
Apr. 81 216 93.75 109.5 88.5 117.75
(3.2) (8.5) (3.69) (4.3) (3.5) (4.6)
May 75 75
(2.95) (2.95)

July 93 93
(3.6) (3.6)
Aug. 75 75
(2.95) (2.95)
Sep. 133.5 138.75 183.75 76.5 133.12
(5.25) (5.46) (7.23) (3.01) (5.24)
Oct. 150 84 205.5 102 135.37
(5.9) (3.3) (8.1) (4.02) (5.32)
Nov. 115.5 115.5
(4.5) (4.5)
Dec. 75 87 81
(2.95) (3.42) (3.59)

Source: Instituto de la Uva, El Tocuyo (Lara), Venezuela. 1989.
*Only values approximating 75 mm (3 in) or over are presented. All measurements are in millimeters.
Approximate equivalent in inches is in parenthesis.


Although cycles initiated during short days take longer to complete,

it appears that pruning for the first cycle should not be performed until

late November because of lingering conditions of tolda and caria (Vargas,

p.c. 1989). Similar conditions prevail from mid-April to mid-June and

explain why pruning for the long day cycle should be postponed until June

(Figure 3). The same pattern of cloud cover holds for the Maracaibo area

where torrential rainfall is minimal, exceeding the critical threshold

only in October (Figure 5). Thus, it is evident that Vargas has used the

100 mm rainfall limit as a surrogate for a more complex and subtle

barrier, involving the influence of tolda and arda on relative humidity

and most likely on effective daylength.

The Creole Hybrids

Hybrids between New World grape species and Old World V. vinifera

cultivars have been planted in Venezuela since well before the modern

viticultural boom. With rare exceptions (10), V. labrusca and V.

aestivalis hybrids from the eastern United States, as well as muscadines

(V. rotundifolia) and a few imports from Florida, have fared poorly,

despite being well-adapted in their latitudes of origin to hot and humid

growing conditions.

On the other hand, early attempts to develop local viticulture were

based on a handful of vigorous, healthy and productive "creole" varieties

which Olmo (1968) recognized as hybrids between V. vinifera and the native

tropical species V. caribaea. The most widespread of these is the so-

called Criolla Negra (Black Creole). Capable of growing to enormous

proportions, with extraordinary yields of acceptable quality red