Soil amendment with bioenhanced bagasse (bagasse colonized by
Trichoderma harzjanum). enhanced bagasse. T. harzienum. Topsin-M and
biocnhanced bagasse + Topsin-M for controlling Fusarium root rot disease on
mandarin under green house and field conditions was studied. In vitro. amended Dox
medium with 2.5 and 5.0% (w/v) of powdered bagasse resulted in enhancement the
antagonistic of T. harzianum ability against F. solani and increased chitinase and
cellulase activities of T. harzianum compared with control (un amended medium). In
green house. Fusarium root rot disease incidence on mandarin seedlings was high
significantly reduced when bioenhanced bagasse, bioenhanced bagasse + Topsin-M
(0.5 gIL) and Topsin-M (1 gIL) treatments were dilervied into artificially infested soil as
twice soil applications compared with control treatment. Moreover. such treatments
caused high reduction on population density of Fusarium propagules in rhizosphere
soil. but Trichoderma propagules counts were highly increased. Under field conditions
amended s oil a round stems 0 f diseased mandarin trees by b ioenhanced bagasse.
bioenhanced bagasse + Topsin-M and Topsin-M as twice application per season
results in recovering great number of diseased trees and decreased the disease
severity on others. Population density of Fusarium sp < /em>p. were highly decreased. where
population density of Trichoderma spp were increased in rhizosphere soil of trees that
treated by bioenhanced bagasse alone or in combined with Topsin-M. Such
treatments caused increased fruit yield by 130.2 and 116.3% compared with 67.4% of
Topsin-M treatment. It could be suggested that using soil amendments such bagasse colonized
by T. tietzienum alone or in combined with a reduced rates of fungicides for
controlling root rot pathogens on citrus can be success fully used replacing traditional
fungicides and avoid environmental pollution.