Pratylenchus, Dioscorea alata Minimize
May 2006. Dry rot of yam, Dioscorea alata, caused by the nematode, Pratylenchus coffeae. The yams were recorded with the disease on the weather coast of Guadalcanal. The nematode is one of a number of factors that have combined to destroy the yam culture of this part of Solomon Islands. It is a tragic loss. This was part of the Solomon Islands that celebrated yam harvest annually, so the loss is significant.

The nematode is not the sole cause of yam decline: the area saw fighting in recent years, forcing people to abandon their villages and gardens, and it is also an area of high population growth and declining garden fallows, conditions that might favour plant disease increase.

The nematode is currently a problem in the Milne Bay and other areas of Papua New Guinea, althogh the problem has not been researched or the species confirmed. The problem seems to be especially severe in the traditional yam-growing areas due to increase in land pressure with growing populations and significant shortening of fallow periods causing not only decrease in production, but also shortage of planting material.