Photo 1. Pratylenchus coffeae in yam causes a shallow rot beneath the skin; the importance of the rot is not only the loss of flesh for eating, it is also the loss of planting material. Yams infected with dry rot do not sprout or, if they do, the cutting will be infested with nematodes which will attack the roots when the setts are planted.

Photo 2. Pratylenchus coffeae in yam causes a shallow rot beneath the skin.

Photo 3. The head of Pratylenchus sp. showing the hollow spear or stylet (arrow), which is used to puncture cells in order to move through the roots, as well as to feed on their contents.

Photo 4. Pratylenchus coffeae inside a root.

Photo 5. Banana roots with purple/black discolouration caused by Pratylenchus coffeae. Infected roots rot and plants are weak and yields are small.

Photo 6. "Toppling" is a common symptom on banana when roots are attacked by Pratylenchus coffeae. Note this banana has fallen over before the fruits have matured; a sign of nematode attack. A similar symptom occurs when bananas are infected by the nematode Radopholus similis.

Diagram. Life cycle of Pratylenchus coffeae.