An Eighteen-Months'-Old Coffea Quillou Tree in Blossom
There are three principal diseases, due to fungi, from which the coffee plants suffer. The most common is known as the leaf-blight fungus, Pellicularia tokeroga, which is a slow-spreading disease, but one that causes great loss. Although the fungus does not produce spores, the leaves die and dry, and are blown away, carrying with them the dried mycelium of the fungus. This mycelium will start to grow as soon as it is supplied with a new moist coffee leaf to nourish it. The method of getting rid of this disease is to spray the trees in seasons of drought.
It was a fungoid disease known as the Hemileia vastatrix that attacked Ceylon's coffee industry in 1869, and eventually destroyed it. It is a microscopic fungus whose spores, carried by the wind, adhere to and germinate upon the leaves of the coffee tree[100].
Another common disease is known as the root disease, which eventually kills the tree by girdling it below the soil. It spreads slowly, but seems to be favored by collections of decaying matter around the base of the tree. Sometimes the digging of ditches around the roots is sufficient to protect it. The other common disease is due to Stilbium flavidum, and is found only in regions of great humidity. It affects both the leaf and the fruit and is known as the spot of leaf and fruit.
Coffea Ugandæ Bent Over by a Heavy Crop