In Uganda, the major pathogen genus causing severe Phaseolus bean root rot is Pythium. There has been no information on the different Pythium species causing root rots and the impact of use of organic amendments on Pythium populations. Analyses identified 11 Pythium species that are currently associated with bean root rots in Uganda. Apart from the traditional species, P. ultimum var ultimum, known to infect beans, the other species recovered were P. spinosum, P. torulosum, P. salpingophorum, P. vexans, P. dissotocum, P. nodosum, P. echinulatum, P. pachyaule, P. oligandrum and P. deliense....