Mucuna pruriens Minimize

Febrary 2008. In Cambodia, velvet bean, Mucuna pruriens, has been grown at 700 meters on acidic soils. Last year there was an excellent crop: 5 kg was planted and 200 kg harvested. This year the velvet beans have a red colour on their leaves and are not thriving.  Some have been planted in the same  ground, other on fresh ground.

The obvious problem from the photo is the presence of leaf spots, but whether they are caused by fungi or bacteria is difficult to say. Their appearance are to those found on Centrosema in Pacific Island countries; see list for e.g. Solomon Isldands at:

There was also a suggestion of lack of nitrogen, but this was not likely to be cause of the problem.