The arsenal of 1955: carbon disulfide injected into borer galleries, sodium arsenate on stumps against coffee wilt disease, chloropicrin and dichloropropene (DD) as soil fumigants against nematodes, and against insects the range of organochlorines and organophosphates of the day: DDT, HCH and lindane, chlordane, aldrin, dieldrin, parathion, HETP/TEPP, paradichlorobenzene. Almost all of it is banned today: DDT withdrawn in most countries since the 1970s, aldrin, dieldrin and chlordane among the first twelve persistent organic pollutants of the Stockholm Convention (2001), lindane added in 2009, endosulfan in 2011, parathion, chloropicrin and arsenicals gone from legal agriculture.

Surviving are Bordeaux mixture, pyrethrum and, for a time, rotenone, since withdrawn in the European Union. Vayssière already pointed out that HCH eliminates entomophagous hymenopterans and pollinators, that is, exactly the beneficial insects whose efficacy he had just quantified, and he recommended the product on the same page: he had the fact without having the thesis, seven years before Silent Spring (1962).

Coste 1955, p. 219, 311-313; Stockholm Convention, annexes A and B; LC ch. 15

Against rust, three groups of fungicides: copper, a contact fungicide, which forms a barrier on the leaf (in Brazil, four to five applications at thirty-day intervals, recommended below 5% incidence); the triazoles, systemic, which act from the inside on the first stages of infection (cyproconazole, epoxiconazole, flutriafol, tebuconazole, triadimenol); and triazole + strobilurin mixtures, mesostemic (azoxystrobin, pyraclostrobin, picoxystrobin, trifloxystrobin), reserved for higher incidences.

About 60% of the products registered against rust in Brazil contain a triazole. Bordeaux mixture, far less effective than the other coppers and “of doubtful value” (Merle et al., 2020), remains attractive in Central America because it is permitted in organic farming. Tank-mixing copper hydroxide with cyproconazole or pyraclostrobin reduces efficacy; fungicide resistance is a growing concern.

Applications begin at the start of the rainy season and depend on the fruit load. On canephora, the UCDA judges chemical control unprofitable and advises against it. Against the berry borer, the Ugandan manual still cites fenitrothion 50% EC (6 ml per 4.5 l at fruit set, then 120-150 days later if needed), cypermethrin, deltamethrin, chlorpyrifos, and an imidacloprid + tebuconazole combination that targets the insect and the ambrosia fungus it feeds on.

On the biological side against rust, the hyperparasite Lecanicillium lecanii (formerly Verticillium), observed naturally on lesions, has been studied since the 1980s without keeping its promises in the field, for lack of being established before the pathogen arrives and of surviving its latent periods; Calonectria hemileiae, Trichoderma harzianum, Bacillus, the mite Ricoseius loxocheles and the snail Bradybaena similaris, which eat the spores, are under trial; mycorrhizae have been associated with fewer infections. Lime sulfur at 0.5% against mites and azadirachtin (neem, 0.025-0.1 g/l) against the leaf miner complete the Brazilian biological toolkit.

BSPP 2022, p. 16-20 (Zambolim 2016; Merle et al. 2020; Vélez and Rosillo 1995); Agronomy 12 (2022), “Coffee Leaf Rust in Brazil”; Crop Protection (2019), copper + triazole mixtures; UCDA 2019, p. 77 and 86; Frontiers in Sustainable Food Systems 5 (2021)