Coffee Is Not Forever. Stuart McCook

it also had stick to the leaf during the heavy monsoon rains. It would need to be toxic to the fungus but not to the coffee plant or the soil. These stringent criteria eliminated most of the chemicals that planters had been trying. Ward enlisted a number of eminent planters in a series of spraying experiments, using various measures (weight of leaves and fruit produced) to assess how farms treated with chemicals fared in comparison to untreated farms. At the time, only sulfur compounds and particularly sulfur of lime met the criteria. In fact, planters found that the lime also acted as a manure, improving the life of the tree. Ward struggled to quantify the amount of benefit that applications of sulfur would give, but most experiments suggested that it offered planters at least some benefit if it was applied at the right time.⁶⁴

      Ward argued that the rust could best be controlled through preventive measures. “The problem of combating this disease,” he argued, “is not a mere matter of quantity of chemicals and their efficacy in killing the fungus, but also in maintaining the strength of the tree and preventing reinfection.”⁶⁵ Like some planters, Ward called for the careful cultivation of coffee—judicious pruning and manuring as well as the systematic elimination of infected leaves and trees. A few years before, planters had argued that manuring actually cured the rust. Ward argued that it did not; in fact, paradoxically, “of every basket of manure placed at the foot of the tree, a certain proportion must be looked upon as serving the mycelium of Hemileia for food.”⁶⁶ Even so, careful manuring was still worthwhile because it would help the trees produce their leaves sooner and retain them longer, allowing the fruit and branches to develop more fully, which would mitigate the rust’s effects. Outbreaks could also be controlled by planting windbreaks that would slow the dispersal of spores.

      Ward’s research was a scientific success, but it was a practical failure—at least as far as Ceylon’s planters were concerned. The planters accepted the basic premise of fungal pathogenicity and Ward’s account of the epidemic; most quietly abandoned their earlier models of disease. But from their perspective, Ward had failed to accomplish his main purpose: he did not offer them any tools to effectively manage the rust. He had shown them why most of their treatments would not work, but he had given little guidance as to what would. So the planters continued to innovate on their own. “We have now,” wrote the planter G. A. Talbot, “all that can be taught us by scientific men about Hemileia, and it is for practical planters, in working their coffee, to study the disease. I must say, I think there is a good deal to be found out yet.”⁶⁷

      In 1880, the planters of Ceylon founded a horticultural journal, the Tropical Agriculturist, that published reports summaries of horticultural research as well as reports from European planters across the tropics. In this sense, the Tropical Agriculturist was a tropical version of The Gardeners’ Chronicle, which published horticultural pieces from both professionals and amateurs.⁶⁸ In the field, some planters continued to experiment with new methods of controlling the disease. One of the most widely reported of these involved the experiments of a planter named Eugene Schrottky who developed what he described as a “vaporization” technique that involved covering his coffee plants with a powder containing carbolic acid. In the local press, however, coffee planters argued heatedly about whether or not Schrottky’s method did much to control the disease. In the end, it was never adopted on a large scale.⁶⁹