L. Mol et al., EFFECTS OF CROP-ROTATION AND REMOVAL OF CROP DEBRIS ON THE SOIL POPULATION OF 2 ISOLATES OF VERTICILLIUM-DAHLIAE, Plant Pathology, 44(6), 1995, pp. 1070-1074
Microsclerotia of Verticillium dahliae are produced in large numbers o
n senescing parts of host plants and remain viable in the soil for man
y years, Changes in the population density, i.e. density of microscler
otia, in the soil were measured in micro-plots using two isolates of V
. dahliae, specific to either field bean or potato, several crop seque
nces comprising potato, field beans and barley, and either the removal
of aerial debris of the crops or incorporation into soil. Potato was
more susceptible to the potato isolate and field bean more susceptible
to the field bean isolate. Removal of debris of potato and field bean
reduced numbers of microsclerotia in the soil in the subsequent years
, but removal of barley straw had no effect. Initially non-infested co
ntrol micro-plots became infested, probably by the growth of potato ro
ots into the naturally infested subsoil. The rate of increase of the m
icrosclerotial population in the non-infested control micro-plots was
larger than in the initially infested treatments, because more coloniz
ed debris was produced. It is concluded that removal of aerial debris
of host crops is important to reduce the soil population of V. dahliae
.