boom made the world’s coffee farms more vulnerable to diseases and pests than ever before. Viewed from an epidemiologic perspective, it greatly increased the global population and distribution of susceptible arabicas. The limited genetic diversity of these cultivated arabicas made them even more vulnerable. The world’s globally traded arabicas depended on just two cultivars, Bourbon and Typica, both of which originated from the narrow arabica populations of Yemen. The expanding shipping and railroad networks offered diseases and pests new opportunities to move beyond their native range. The most significant change, however, was the spread of coffee monocultures; many of the new coffee farms were radically simpler than earlier ones. These monocultures involved a trade-off between economic productivity and ecological vulnerability, which may not have been immediately apparent. By sharply reducing the biological diversity of farms—by devoting the farm space to a single crop—farmers also removed the physical and genetic obstacles that kept diseases and pests in check. Looking back on this period, the French coffee expert Auguste Chevalier wrote that “the coffee plant was cultivated on still-virgin lands, in regions not wholly deforested; all the cultivated coffee trees descended from a handful of plants free of disease; and they were cultivated in lands where insects [and] natural enemies of the coffee tree had not yet been imported.”54
Harbingers of the Rust
A closer look suggests that Chevalier’s idyllic picture of coffee farming was not entirely accurate. As early as 1773, a French coffee planter on Île Bourbon complained of “little black scarabs that eat the leaves of the coffee tree,” of a “louse that attaches itself to the branches, leaves, and even the roots of the coffee trees, and makes them languish,” and of a “singular malady” in which the “leaves, branches, and often even the fruits of the coffee tree were largely covered with a black matter that ‘freezes’ the plant and dries it.”55 These localized outbreaks foreshadowed the global commodity diseases that were to plague coffee farms in the next century.
Even as the world’s coffee farms became more vulnerable to disease before 1870, they suffered only localized outbreaks of diseases and pests. A “coffee leaf disease,” likely an insect rather than a fungus, disrupted production on coffee estates in Ceylon for a few years in the 1840s. Indeed, during the pioneering phases of coffee production, insect pests tended to cause more problems than did diseases. Various species of mealybugs (genus Planococcus) fed on the sap of new tissues in the coffee plants. One of these, the “black bug”—which first appeared in Ceylon in 1843—ate the fresh shoots of young coffee plants and destroyed the cherries. Another, the “white bug,” lived in the axils of leaves and cut them off “either during the blossom stage or just after the young berries have been formed.”56 The most serious insect pest of coffee was the borer (probably the coffee white stem borer, Xylotrechus quadripes Chevrolat), first detected in Coorg in the mid-1860s.57 This insect bored into the trunk of the coffee tree. The leaves of infested plants wilted and fell, and over time the tree died back to the entry point.58 Grubs sometimes attacked the coffee plant’s taproots, ultimately killing the trees. The planters also faced problems from grasshoppers, “which [were] addicted to cutting down young trees close to the ground, and to sawing off the branches of older trees.”59
While some of these pests were undoubtedly native to Ceylon, others were probably introduced, particularly from other parts of South Asia. The “coffee bug” that appeared in Ceylon in the early 1840s was previously unknown in Ceylon; apparently these insects were first detected on “plants near coolie lines” of laborers from southern India. Some planters argued that the insect emerged spontaneously in poorly cultivated plantations. Others, however, attributed the introduction of the bug to “Mocha” coffee plants imported from Bombay. George Gardner, the botanist of the Peradeniya Botanic Garden, noted that the insect had not been present on the island five years before. The planters also noticed that the outbreaks of the bug were associated with outbreaks of a fungus. The naturalist Miles Berkeley concurred, noting that “there is a great reason to believe that many of these plagues are in the first instance imported, and we know that some vegetable productions of foreign extraction and some insects also become peculiarly luxuriant and abundant in their new quarters.”60
The entomologist John Nietner disputed this idea. “With reference to this comparatively recent appearance of the bug in the island,” he wrote, “it has been suggested that it was not indigenous, but had been introduced with seed-coffee, from some other country.” But he argued that the bugs were indigenous, noting that he had seen the white coffee bug “upon orange, guava, and other trees,” while the brown bug “attacks almost every plant and tree that grows on a coffee estate, more particularly though those that are grown on gardens.”61 Nietner did not explain why the outbreaks occurred at that particular time, but he was clearly aware that they were connected to prevailing farming practices.
Significantly, Nietner was also aware of the broader global context of these outbreaks, noting that “at about the same time [as the bug outbreaks in Ceylon] the potato, vine, and olive disease[s] became very alarming in Europe.”62 This was a historical moment in which microorganisms were becoming increasingly mobile. It was in these years, for example, that the potato blight made its way from South America to Europe and cholera spread from India to Europe and later the Americas.63 Microbes like these traveled on the same modern transportation infrastructure that swiftly moved goods and people around the globe.
Yet for the first half of the nineteenth century, at least, the coffee plant (and by extension the coffee rust) did not circulate. There was little incentive for coffee planters, large or small, to move the coffee plant. It had been so widely distributed in the eighteenth century that further long-distance transfers were unnecessary. Coffee planters almost everywhere could easily obtain planting material locally and saw little advantage to acquiring it from afar. In Ceylon and Southern India, for example, coffee planters obtained planting material from plants that had escaped into the forest, or they purchased planting material from local farmers. Long-distance transfers of coffee began anew in the 1870s, when Europeans found a new species of coffee—Liberian coffee—in West Africa.64
By the late 1860s, the pioneering phase of coffee cultivation was ending in India, Ceylon, and Java—the region’s three largest producers. In Ceylon, most of the viable coffeelands were occupied by the mid-1870s. In India, the coffee zones in Mysore and Coorg were similarly almost fully occupied. “Comparatively little land suitable for planting purposes now remains in the hands of the government in either the Neilgherries, Coorg, or Wynaad,” wrote Edmund Hull in 1877, “while there is great difficulty in securing what there is at any price, except under the most stringent conditions.”65 George Watt wrote that the coffee tracts of Southern India “extend in nearly an unbroken line along the summits and slopes of the Western Ghauts, from the northern limits of Mysore down to Cape Comorin.”66 Java was ringed with a coffee belt extending from 600 to 1,200–1,400 meters above sea level.67 The ecological limits of coffee cultivation—as defined by a combination of temperature, rainfall, and climate—had been reached. Nonetheless, coffee planters in these places continued to open new farms in marginal lands or migrate to new frontiers. Some astute planters began to question the long-term viability of the pioneering estate model, which treated forest landscapes and their soils as nonrenewable resources. Hull questioned the “great and serious difficulties in the way of keeping up that constant, unremitting care and culture which appear necessary to maintain in a state of perfect health a plant, which, however hardy in some respects, is after all an exotic in our Indian settlements, and is moreover being grown under a forced and artificial system.”68 Hull found an alternative model in the native farms, some of which contained “trees of an age far beyond the power of the oldest inhabitant to define, and which have very probably been flourishing for generations.”69 Unfortunately, it seems that Hull’s voice was in the minority.
BY THE mid-nineteenth century, the intensification of production had left the world’s coffee farms highly vulnerable to diseases and pests. This vulnerability was itself a product of coffee’s history as a
