Biological Control of Sclerotium rolfsii, Causing Stem Rot of Groundnut by Pseudomonas cf. monteilii 9

In an attempt to develop effective biocontrol system for management of stem rot disease caused by Sclerotium rolfsii in groundnut, 11 Pseudomonas spp. isolated from rhizospheric soil, were evaluated for their antagonistic activity against Sclerotium rolfsii. A soil bacterium identified as, Pseudomonas cf. monteilii 9, showed highest antagonistic activity against Sclerotium rolfsii. In dual cultures, the Pseudomonas cf. monteilii 9 inhibited the Sclerotium rolfsii up to 94 % in terms of dry weight. Pseudomonas cf. monteilii 9 produced diffusible antibiotic, volatile metabolites, hydrogen cyanide and siderophore which affect Sclerotium rolfsii growth in vitro. This strain also produced a clear halo region on skim milk agar plates, indicating that it excretes protease which played vital role in inhibition of S. rolfsii. In pot assay for control of Sclerotium rolfsii, Pseudomonas cf. monteilii 9 treated seeds showed decrease in incidence of disease up to 45.45 to 66.67% in comparison to untreated seeds

Redução de perdas de estacas da pimenteira-do-reino causadas por Sclerotium rolfsii no pré-enraizador.

bitstream/item/36250/1/ORIENTAL-BPD54.pdfVersão eletrônica. 1ª impressão: 2009

Efficacy of Trichoderma against Sclerotium rolfsii causing collar rot disease of lentil under in vitro conditions

Three biocontrol agents viz., Trichoderma viride, T. virens and T. harzianum were evaluated to test the antagonism against Sclerotium rolfsii under in vitro conditions. All the three antagonists’ viz., T. viride, T. virens and T. harzianum have shown the potential of parasitizing the growth of Sclerotium rolfsii in vitro. The rate of inhibition was fastest in T. harzianum (63.60%) followed by T virens (51.5 %). Least inhibition was recorded in T. viride (50.85% ) after 72 hours of incubation. However, T. viride showed the highest (91.31%) reduction in sclerotia formation followed by T. harzianum (84.92%) and T. virens (84.29%) after 15 days of incubation. The volatile compounds from Trichoderma viride were found most effective in suppressing the mycelial growth (51.11%) and sclerotia production (95.90%) of the target pathogen. The culture filtrate from both T. harzianum and T. viride (15% concentration) was found very effective in inhibiting the radial growth (57.46 and 49.62%) and sclerotia formation (98.20 and 99.83%) of Sclerotium rolfsii. The antagonists such as T. harzianum and T. viride can be used as a bio-control agent against S. rolfsii under field condition

Grão de bico e lentilha: duas novas hospedeiras de Sclerotium rolfsii no Planalto Central do Brasil.

Neste trabalho, relata-se, pela primeira vez, a ocorrência da murcha-de-esclerócio, causada por Sclerotium rolfsii em grão-de-bico (Cicer arietinum L.) e em lentilha (Lens culinaris Medikus) na Região do Planalto Central do Brasil.bitstream/item/85036/1/bpd-92.pd

THE POSSIBILITY OF CONTROLLING SCLEROTIUM ROLFSII ON SOYBEAN (GLYCINE MAX) USING TRICHODERMA AND TEBUCONAZOLE*)

ABSTRACT The possibility of  controlling S.  rolfsii on soybean  (Glycine max) var. Rinjani using T. aureoviride  and Tebuconazole  under  field  conditions was  studied. The  experiment was  conducted  at  the  experimental  plot  of SEAMEO BIOTROP. The pathogen was mixed with the soil (2 kg/plot) 4 days before the inoculation of the antagonist  (2.25 kg/plot). The measurement of each plot was 2.5 x 6 m2. N, P and K (120 kg/ha) were applied at the same day with the inoculation of the pathogen. Soybean seeds were planted 7 days after the inoculation of the antagonist. The distance between plants and between plots were 20 and 40 cm, respectively. The  fungicide  at  concentration  of  100  g/ha  (in  vitro  concentration)  and  210  g/ha  (field  or recommended concentration) were applied using 2 methods, i.e. 1) spraying on the planting hole at the same day as the planting of soybean seeds, and 2) spraying on the soil surrounding the plants 7 days after planting. Soils that were neither inoculated with the antagonist nor the fungicide were used as controls. Three replications (3 plots) were used for each treatment (including the control). The results showed that the inoculation of the antagonist, the concentrations of the fungicide, and time of application gave very significant differences in the percentages of the plants infected by the pathogen and significant differences in seed production; while the interaction between the inoculation of the antagonist and the concentrations of the fungicide, between the concentrations of the fungicide and the time of application, and between the inoculation of the antagonist, the concentrations of the fungicide and the time of application did not  give  significant  differences  either  in  the  percentages  of  the  plants  infected  by  the  pathogen  or  seed production. The percentage of plants infected by the pathogen was lower on soil inoculated with the antagonist (31.6%) than on soil not inoculated with the antagonist (52.9%). The percentage of plants infected by the pathogen was lower on soil treated with the fungicide either at in vitro concentration (37.5%) or at field concentration (37.4%) than on the soil not treate

Trichoderma species as Biocontrol Agent against Soil Borne Fungal Pathogens

Soil borne pathogenic fungi are of major concern in agriculture which significantly decreases the plant yield. Chemically controlled plant imposes environmental threats potentially dangerous to humans as well as other animals. Thus, application of biological methods in plant disease control is more effective alternative technique. This study was carried out to isolate Trichoderma species from soil sample and to assess its in vitro biocontrol efficacy against fungal pathogens viz. Sclerotium rolfsii, Sclerotionia sclerotiorum, Fusarium solani and Rhizoctonia solani. Biocontrol efficacy testing of isolates against different fungal pathogens was performed by dual culture technique.In this study, 5 different Trichoderma species were isolated from 26 various soil samples and were tested against four fungal soil-borne pathogens. Inhibition percentage of radial growth of Sclerotium rolfsii by three of the Trichoderma isolates was found to be 100%; about 62% and 68% of maximum inhibition was observed against Rhizoctonia solani and Fusarium solani respectively whereas Sclerotionia sclerotiorum was inhibited maximum up to 23%. This in vitro study revealed that although Trichoderma species plays an important role in controlling all type of soil borne fungal plant pathogens, however, isolates as biocontrol agent against Sclerotium rolfsii was found to be more efficient in comparison to other pathogens.Nepal Journal of Biotechnology. Dec. 2017 Vol. 5, No. 1: 39-4

Penghambatan Serangan Sclerotium Rolfsii Penyebab Rebah Kecambah pada Kedelai dengan Bakteri Kitinolitik

The inhibition of Sclerotium rolfsii as causal agent of soybean damping off by using chitinolytic bacteria were studied in Laboratory of Observation Pest and Disease UPT-BPTPH 1 and Laboratory of Microbiology, Department of Biology, Faculty of Mathematics and Natural Sciences, University of Sumatera Utara, Medan. The aim of this research was to investigate the ability of chitinolytic bacteria to inhibit the growth of S. rolfsii. Six isolates of chitinolytic bacteria were used in this study. The inhibition zone between colony of the bacteria and the fungus was measured. The result showed that the bacterial isolates has different ability in inhibiting the growth of S. rolfsii. Enterobacter sp. BK15 and Bacillus sp. BK13 were the most effective in inhibiting the growth of S. rolfsii with inhibition zone of 3.70 cm and 3.75 cm, respectively. The less effective was shown by Enterobacter sp. PB17 with inhibition zone of 0.10 cm, while Enterobacter cloacae LK08 have no ability to inhibit S. rolfsii. The seeds soaked in bacterial suspension by Bacillus sp. BK13 dan Enterobacter sp. BK15 were able to reduce damping off by 44.4% and 50%, respectively