Of avocados and Central America's biodiversity heritage

Plaza Mayor, Antigua Guatemala, Central America

"In recognition and appreciation of the great contribution of Antigua and all of Guatemala to the development of the avocado industry in California" reads a plaque nested among the flower beds of the Plaza Mayor, in the Spanish colonial city of Antigua Guatemala. Behind that plaque, placed in 1946 by the California Avocado Society, is one of many stories closely linking Guatemala with the Golden State.

By now, it is part of the popular lore in California that a postal worker from the city of La Habra Heights, in Los Angeles County, received in the late 1920s some avocado seeds originating from Guatemala, which resulted in trees that yielded fruits with a dark, rough skin. Despite their unattractive exterior appearance, these avocados turned out to be something special. One of the trees that grew from those seeds produced a particularly more tasty and buttery fruit than the varieties available until then in local markets, a tree with decidedly superior characteristics. In much the same way that other fruits were improved at the time (and even today), Mr. Rudolph Hass —such was the name of our postman— collected the seeds from the fruits of this super tree, to grow seedlings with similar characteristics. Not one to miss an opportunity, the accidental owner patented his tree, and set out to market its descendants' seeds for distribution, first in California, and then, beyond its borders. The avocado named after himself is now the most popular in the world. But this anecdote is just one stop in the history of avocados in California.

Our story includes, among its beginnings, a nursery of fruit species in the town of Altadena, also in Los Angeles County, at the beginning of the 20th century. Its owner, Mr. Frederick Popenoe, stocked his nursery with small trees of Mexican avocados, with varieties collected in trips to that country. Helping him in his business were his two sons: Wilson and Paul Popenoe.

To increase the diversity of their products, both Popenoe boys were sent in 1913 by their father to collect fruit seeds from around the world. They traveled through the Middle East, Africa, the Caribbean islands, and Latin America. Wilson, the youngest of the brothers, later accepted employment as an explorer for the United States Department of Agriculture, and thus traveled through Brazil, Central and South America, studying and documenting many varieties of fruits.

Wilson soon became quite knowledgeable of tropical fruits, and wrote his "Handbook of Tropical and Subtropical Fruits" in 1924, still considered the best guide on the subject today.

West India Gardens, a fruit tree nursery in Altadena, CA, owned by Frederick Popenoe, ca 1915.

The avocado had already been described by the first Spanish explorers of the 'New World'. Gonzalo Fernández de Oviedo, member of the expedition of Hernán Cortez against the metropolis of Mexico-Tenochtitlán in 1519, described the fruit as "a paste similar to butter and of good taste... these pears are excellent, they are cut before ripening and stored until they are perfect to eat..." From the Nahuatl name, ahuacatl, used by the people of Mexico for the fruit, came "aguacate" in Spanish, and "avocado" in English.

In fact, avocados of a thick-skinned variety from Atlixco, in the state of Puebla, Mexico, had been introduced to California since the mid-nineteenth century. During a harsh winter in 1913, most of these first trees in California died, with the exception of a few in Frederick Popenoe's nursery. Recognizing the particular resilience of one of them, he propagated it and gave it the name of "Fuerte" ("Strong" in Spanish) for having survived the great frost. Such variety was cultivated in the Yorba Linda region, near Los Angeles, and is said to have given rise to the first commercial avocado plantation in California.

Already an employee of the North American Department of Agriculture, Wilson Popenoe became an envoy to Central America, to explore avocado varieties for several years. However, for a long time he was not able to identify a variety more resistant to the drastic changes of the California climate than the Fuerte. His experiences with the Guatemalan avocados were recorded in his 1919 book "The avocado in Guatemala", which described no only dozens of varieties, but also the many ways in which Guatemalans consumed it.

In 1915 the California Ahuacate Society was formed, which later adopted the name of California Avocado Society. By 1920, the Fuerte variety had become a favorite of local consumers. However, the plantations had short harvest seasons, and very variable yields.

It was in the early 1920s when the aforementioned Mr. Rudolph Hass accidentally received seeds of a fruit native to Guatemala, whose seedlings failed to graft onto the Fuerte variety. He finally allowed some of the seeds of the new variety to germinate and grow on their own. One of these plants, as we mentioned before, produced fruits that, although externally unattractive, were of outstanding taste and nutritional content, which led Mr. Hass to patent his tree in 1935, a first for any kind of tree. It is said that the parent tree of the new Hass variety lived in La Habra Heights until 2002, when it finally succumbed to a root disease. It was 76 years old.

Avocados of the Fuerte (Mexican) and Hass (Guatemalan) type

United States patent for the Hass avocado (1935). The description reads: "the original tree is a Guatemalan seedling of unknown parentage. It was planted in the spring of 1926..."

Artificial selection

A method of improving crops of fruit species such as the avocado follows a rather simple concept: select the phenotypes that are desirable from a plantation for further propagation, while those varieties with lower yield or lower quality are eliminated from the orchard. The methodology was already practiced, though not systematically, by the pre-Columbian inhabitants of Central and South America, resulting in more developed varieties of corn, cacao and avocado, in comparison with their wild counterparts. That is to say, when replanting seeds of individual trees whose fruit they favored, they also eliminated from the orchard the weak and unproductive individuals, to obtain a plantation with better yield and fruit characteristics.

Such method continues to be practiced today to improve plant varieties. The search for a superior fruit (or any plant product, for that matter) involves first identifying the desirable varieties, and then propagating them to again select, at the individual plant level, those that show most promise. This is repeated in subsequent generations until, after a few iterations, one arrives at seedlings with the desired attributes, and capable of passing their qualities to their offspring.

Wison Popenoe's footprints in Central America

The name of Wilson Popenoe is associated with the Zamorano Agricultural School, in Honduras, of which he was a co-founder and first director since 1942. His last name is also associated to several species of Guatemalan fruits and flowers, which bear his last name in their scientific designation. In Antigua Guatemala, in whose surroundings he did much of his research on avocados, Wilson and his wife Dorothy bought a house within the colonial city and furnished it with authentic Spanish colonial items. It is now a tourist attraction known as the "Popenoe House."

A very special avocado

Among the dozens of wild avocado varieties native to Guatemala, one is notable for its minute size. So much that the casual observer may well conclude that it is not the most important within the ecosystem. However, its importance cannot be overstated, as it is the main sustenance for the quetzal, the sacred bird of the ancient Maya and national bird of present Guatemala. Also belonging to the genus Persea, the tiny, round fruit is locally called aguacatillo (little avocado). The photograph shows a female quetzal surrounded by several aguacatillos in Alta Verapaz, Central Guatemala.

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Explorations into the Dark Side

The explorations of the Popenoe family resulted in a food revolution not only in California, but throughout the world. The effort of such horticulturist-explorers, assisted by a dose of good fortune, allowed the identification and improvement of what would become the current super avocados. But like many a success story, this one also has a dark component.

Guided no doubt by the success achieved with fruit species, and also influenced by social currents of his time, Paul Popenoe, the older brother, began in those early years of the twentieth century to promote the idea that, just like fruit trees, the human species could also be improved and eventually become a superior variety, with better health, disease resistance, superior intellect, etc., through the method of artificial selection. This method, applied to humans, is known as Social Darwinism, and encourages within a society the reproduction of human types considered superior by it, while restricting the possibility of reproduction of individuals considered defective or of races deemed inferior.

Certainly, Paul Popenoe was not the first to promote this idea, which was already known by the name of Eugenics since 1883, when it was founded by Sir Francis Galton, an English anthropologist and sociologist. But, enthusiastic about the application of this new "science", Paul co-wrote the book Applied Eugenics in 1918.

Sadly, the book promoted racist ideas that were acceptable and commonplace at the time, declaring that "the immigration to the country (USA) of people of inferior qualities brings not only undesirable traits, but also damages those superior traits already present here", a feeling that has been reawakened in the United States in recent years, even when it was believed to have been discredited after the atrocities of Nazi Germany. The rhetoric used in the book is, painfully, the same that is often heard these days: "America does not now receive the best of the races to contribute to its population ... we receive the three "d's" : the defectives, the delinquents and the dependents "(Applied Eugenics, 1920 edition, page 302).

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The avocado industry as a future model for Central America

The United States produces some 150,000 tons of avocados, worth $392 million, as of 2017. 86% of all plantations in the United States are located in California, mostly in the vicinity of San Diego (40%), Ventura (22%) and Riverside (11%) counties. The Hass variety, of Guatemalan origin, constitutes 66% of plantations in the state, and 95% of all avocados consumed in the country. This variety occurs throughout the year, except for the months of October to November. These amounts are eclipsed by huge imports from Mexico, about $2,600 million, mainly of the Hass variety.

Even in the present, the impulse to create new varieties of avocado adapted to other regions and climates of California and beyond, and producing fruit throughout the entire year, continues. To this end, research centers specializing in this crop have been formed at institutions such as the University of California at Riverside and Davis. See for example, https://ucrtoday.ucr.edu/49142

While it is surely a source of pride for Guatemala to be recognized as the genesis of such an important food industry in the north, one also wonders how much did the Central American country benefit from the wildly successful commercialization of this product abroad. After all, it was Wilson Popenoe himself who conceded that "the splendid avocados of today are, without a doubt, the product of centuries of selection, more or less unconsciously, by the Guatemalan indians, who call it oj in their native (Mayan) language".

Ironically, while the nutritious avocado varieties created a multi-million dollar industry in the United States, famine continues to afflict the population at its place of origin, particularly through the so-called dry corridor of Guatemala, Honduras and El Salvador. Such extreme poverty, in turn, forces many Central Americans to risk everything in an attempt to emigrate to the United States.

Without dwelling too much in the past, one can ask how can Guatemala, as well as the other Central American countries, take advantage in the future of the native products of their land? Even now, there are thousands of plant species in the tropics whose properties have not been fully studied, which can be exploited for the benefit of not only the local population, but also of people around the globe. By identifying such species, treating them as intellectual property (through patents), and enhancing their quality through collaborations among national and international universities and agriculturists, these species can become a source of jobs, income and sustenance for the local population, as well as a source of income from licensing deals with growers abroad.

The Central American countries are small in territorial extension, but include highly fertile valleys and mountainsides. Plantations are either in the hands of large growers with significant economic resources, or distributed among many small growers who, by themselves, do not have the capacity and expertise to develop and commercialize new, attractive varieties in international markets. The small plantation owners, however, can unite and work cooperatively with universities and research institutions in their own countries, as well as collaborating with international experts, to develop and commercialize new varieties that present not only great market appeal but are also resilient to the stresses of climate change. These countries can then leverage their biodiversity, climate and geographical location, to establish seedbeds of native species, improved and adapted to different environments via the most advanced horticultural practices. In short, a sort of seedbed to the world, a model based not only on physically exporting large quantities of products, but on generating revenue as royalty from propagation licenses that can then be reinvested by the community in training, education and job creation. This model can be extended not only to fruits and flowers, but also to other natural products, such as unique species of precious woods native to the region.

In summary, as the Central American countries learn from the lost opportunities of the past, they can develop a new awareness for the value of their biodiversity, creating projects with direct economic impact for their citizens. By actively engaging in the discovery of new varieties of highly nutritious fruits, and making them available to their own population, as well as to others, they can help mitigate the scourge of food insecurity, expected to become more difficult by the effects of climate change.