BANGLADESH JOURNAL OF FOREST SCIENCE
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
Five Trichoderma strains such as T. virens IMI-392430, T. pseudokoningii IMI-392431, T.
harzianum IMI-392432, T. harzianum IMI-392433, T. harzianum IMI-392434 were tested for efficacy to
inhibit and overgrowth of mycelia of Fusarium solani, a causal agent of root rot of Ashwagandha on
potato dextrose agar (PDA) medium. Duel culture technique showed that all Trichoderma strains
effectively inhibited and overgrew mycelia of the pathogen, especially T. harzianum IMI-392432
providing the highest percent of inhibition of radial growth (PIRG) (69.32 %) and overgrowth mycelia
(59.28 %). Liquid culture filtrates having 75% concentration extracted from 30-day-old T. harzianum
IMI-392432 showed the highest percent inhibition of mycelia growth (PIMG) value of 76.23% by using
normal poison agar technique. Further, highest percent inhibition of conidial germination (PICG) (82.86
%) of the pathogen was exhibited by T. harzianum IMI-392432 at same culture and concentrations. In this
study it was observed that different Trichoderma strains have good antagonistic effect on Mycelial growth
and conidial germination of F. solani. In each case, T. harzianum IMI-392432 performed the best
bio-control agent against A solani causing root rot disease of Ashwagandha
In 1990, a serious root rot disease was
observed in different strip plantations of Court
Chandpur-Subdalpur railroad, Jessore-Benapole
highway and Jessore-Satkhira road of greater
Jessore district. These plantations were covered
with trees such as Cassia siamea, Acacia
auriculiformis, A. nilotica, Albizia procera, Leucena
leucocephala and Dalbergia sissoo. The affected trees
died in patches showing wilting symptoms. C.
siamea, A. auriculiformis and A. procera were
affected most, whereas A. nilotica, L. leucocephala
and D. sissoo were least affected. The leaves of the
diseased trees became brown, dried up and
remained attached to the dead branches. After
excavation of roots, whitish mats of mycelia were
observed on the branch and anchor roots of the
trees. Typical fruit bodies were seen on the collar
region, exposed roots and on Clerodendruni
viscosum and Glycosmispentaphylla situated at the
vicinity of the infected trees (Figs. 1 and 2). The
bark of roots were rotted and, in most cases, the
rotting was extended up to the collar region. The
fungus responsible for the disease was isolated
and identified as Fames lignosus (Klotzsch) Bres.
Heavily infected trees were removed from the
sites. Basal area covering one metre radius of each
diseased tree was drenched with 2% commercial
formalin. The second spray was given 15 days
after the first. The sprays, however, could notsave
the diseased trees butfurtherspread ofthe disease
symptom was checked
Sandal wood, Sautalum album L. contains
fragrant oil in the scented heartwood which issold
by weight, and perhaps it is the most precious
wood in this part of the world (Troup 1921).
However, Bangladesh imports sandal wood for
commercial purpose. Recently, the Bangladesh
ForestResearch Institutehad undertaken research
work on the silvicultural aspects of this species to
help raise its commercial plantations. The Forest
Department has undertaken an afforestation
project with this species. As a consequence,
hundreds of seedlings were raised in polybags in
January, 1993. A serious root rot disease was
observed in late February of the same year.
The typical symptom of the disease was
manifested through the gradual browning of the
leaves of the seedlings. Brown spots appeared
first on the branch and tap roots, which later
turned black. The leaves of the infected seedlings
lost their freshness and began to die out with the
stem standing erect. The disease caused 50%
mortality of the seedlings within 3-5 days. One
fungus, Fusarium moniliformae Sheld. was consistently isolated from the samples. A pathogenicity
test confirmed that the fungus was the pathogen
of the root rot.
The root rot ofsandal wood seedlings was
successfully controlledby the use ofDithaneM-45
@ one gram/I of water. The fungicidal mixture
was sprayed over the diseased and healthy
seedlings in such a way that the mixture could
reach the rootsystem. A second spraywas applied
after an interval ofone week. Arrangermentswere
also made for allowing sufficient light on the
seedlings for about six hours a day.
This disease is a new record on sandal
wood in Bangladesh. Although root rot is a
common phenomenon in our forest nursery, the
disease was indeed a serious one. No report of
such kind of root rot is available. Excess moisture
causes damping-off to the sandal wood seedlings
(Troup 1921). However, it was not a case of
damping-off. F. moniliformae is mainly a soilbome
fungus which can cause leaf blight of maize, foot
rot of rice and mango floral malformation
(Rangaswami 1988). It also causes pre-and
post-emergence seedlings blight of maize
(Baruah et al. 1985). Rahman et al. (1980) isolated
F. moniliformae from agar,Aquillaraiaagallocha tree.
The fungus can survive in soil for a long period,
and isfound in fields having general deficiency of
water (Singh 1983). In Bangladesh, January and
February are the months of dry and cold
period of the year. So, this may be the favourable
time for its sporulation and infection in our
country
Welcome to the Bangladesh Journal of Forest Science (BJFS) – a leading platform for advancing the knowledge and understanding of forest science in Bangladesh and beyond. Established with a commitment to excellence, BJFS serves as a cornerstone for researchers, practitioners, and enthusiasts dedicated to the sustainable management and conservation of forest ecosystems.
