Coffee wilt disease

one branch, or one whole side of the bush, suddenly wilts and turns yellow while the rest still looks green. The leaves lose their shine, curl inward, droop and hang down — and unlike a thirsty tree, they do not perk up after rain or watering.

the yellowing and leaf-drop move branch by branch until the whole bush is bare and dead, often within a few months. On a dying branch the cherries often ripen too early (red berries on a sick branch), and the bark may split in long cracks up the stem.

scrape the bark off a wilting stem, or cut a slanting slice into it, and you will see blue-black, brown or purple streaks staining the wood underneath (healthy wood is creamy white). On stems that have been dead a while you may also spot rows of tiny dark bumps on the bark — that is the fungus making its spores.

a thirsty tree wilts all over evenly and recovers once it rains or you water it; wilt disease starts one-sided, keeps getting worse, never recovers, and stains the wood dark inside. Waterlogged or root-eaten trees wilt too, but their wood stays clean and pale — no dark streaks.

watch most closely from berry-filling through ripening and harvest (mid- and late-season), and in the weeks during and just after pruning or picking — that is when the tree is under water stress and when knives, hands and soil are moving wounds and spores from bush to bush.

every couple of weeks walk a big "W" across the plot so you pass through all four corners and the middle, not just the row beside the path. Look hardest at bushes next to a spot where a sick tree was already pulled out, near paths, and downhill from any past infection — soil and water carry the fungus that way.

look for a branch or one side that is yellowing, drooping and not recovering while the rest is green. On any suspect, scrape a little bark near the base and check for the blue-black or brown streaks in the wood — that is what confirms it is wilt disease and not thirst or hunger.

this is not a pest you count up to a percentage. Even a single bush showing progressive one-sided wilt that does not recover, with dark-stained wood, means act today — treat it as a sanitation emergency (a clean-up you cannot delay) before it seeds the whole field. Mark every suspect bush the same day you find it.

the moment you confirm one (one-sided wilt that won't recover, plus dark-stained wood), uproot the whole bush — roots and all — and burn it. If you leave the stump or roots in the ground the fungus stays alive and spreads through root contact to the next tree. Do not drag the sick plant across your healthy rows, and never chop it into mulch — that only spreads the spores.

do not waste money on any fungicide sold as a cure; no chemical can save an infected tree, which is exactly why removing sick bushes fast matters so much. Instead quarantine the affected patch — keep soil, tools, seedlings and picked cherries from moving out of it into your clean blocks, and clean your boots and tools before you leave it.

if new bushes keep wilting despite roguing, treat the whole patch as contaminated — stop moving anything out of it and rest the ground, and do not replant coffee in the same spots for at least a season. Where a block is mostly dead, clear and burn it, rest the soil, and re-establish with resistant seedlings elsewhere rather than pouring more work into feeding the epidemic.