Biological Control of Tomato Seedling Damping off with Streptomyces sp.

2005 ◽  
Vol 4 (2) ◽  
pp. 91-95 ◽  
Author(s):  
D. Dhanasekar ◽  
P. Sivamani ◽  
A. Panneersel ◽  
N. Thajuddin ◽  
G. Rajakumar ◽  
...  
Keyword(s):  
Biological Control ◽  
Damping Off ◽  
Tomato Seedling ◽  
Streptomyces Sp

scholarly journals Application of plant extracts and Trichoderma harzianum for the management of tomato seedling damping-off caused by Rhizoctonia solani

2020 ◽  
Vol 116 (11/12) ◽  
Author(s):  
Mapula T.P. Hlokwe ◽  
Mapotso Kena ◽  
David N. Mamphiswana
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Plant Extracts ◽  
Trichoderma Harzianum ◽  
Moringa Oleifera ◽  
Plant Diseases ◽  
Yield Reduction ◽  
Biotic Factors ◽  
Damping Off ◽  
Tomato Seedling

Seedling production under smallholder farming systems can be negatively affected by both abiotic and biotic factors. Seedling damping-off caused by Rhizoctonia solani is one of the major biotic factors which causes significant yield reduction. Management is mainly based on the application of synthetic fungicides and cultural practices. However, both methods have limitations which result in their inefficiency. Several studies have reported on the use of plant extracts and biological control to manage plant diseases. The aim of this study was to formulate an effective and practical approach to manage tomato seedling dampingoff using extracts of Monsonia burkeana and Moringa oleifera and a biological control agent Trichoderma harzianum. The efficacy of both extracts was investigated under laboratory conditions to determine the most suppressive concentration to R. solani growth. Methanolic extracts from both plants significantly suppressed pathogen growth at different concentrations. M. burkeana significantly reduced R. solani growth at 8 g/mL (71%) relative to control whilst Moringa oleifera extract reduced pathogen growth by 60% at a concentration of 6 g/mL. The highest suppressive concentrations were further evaluated under greenhouse conditions to test their efficacy on seedling damping-off. In damping-off treatments, both plant extracts and T. harzianum also significantly reduced (p=0.5) pre- and post-emergence dampingoff incidence. M. burkeana recorded the highest suppression at 78%, followed by M. oleifera at 64%. Trichoderma harzianum reduced incidence of damping-off by 60% and this was higher than both plant extract treatments.

scholarly journals The biological control of seed-borne Alternaria brassicicola of cruciferous plants with a powdery preparation of Streptomyces sp.

1987 ◽  
Vol 59 (3) ◽  
pp. 199-208 ◽  
Author(s):  
Risto Tahvonen ◽  
Hanna Avikainen
Keyword(s):  
Biological Control ◽  
Brassica Species ◽  
Fine Sand ◽  
Alternaria Brassicicola ◽  
Damping Off ◽  
Streptomyces Sp ◽  
Seed Dressing ◽  
Dry Conditions ◽  
Cruciferous Plants ◽  
Different Origin

The effectiveness of a powdery preparation of a Streptomyces sp. isolate as a seed dressing agent against seed-borne Alternaria brassicicola on different Brassica species was investigated in the study. The preparation was made by freeze-drying and milling the biomass produced in a fermentor into a form suitable for use as a dusting agent. Seed dressing was 80—90 % successful in controlling damping-off from seeds artificially infected with A. brassicicola. The effectiveness of dressing remained unchanged on seeds stored under dry conditions for 5—6 weeks, but subsequently decreased slowly and was ca. 50 % six months after dusting. Streptomyces dressing controlled, in a manner comparable to chemical dressing with thiram, damping-off caused by Alternaria fungi on seedlings which were grown from commercial seed lots of different origin. The results of biological control of damping-off did not vary in the peat lots of different origin whose natural disease suppressivity varied considerably. The control result was the same or better than chemical dressing with thiram. The acidity of the substrate (pH 4.8—8.6) had no effect on the effectiveness of biological control. The results obtained against Alternaria damping-off were the same in other substrates clay, fine sand and mull as in peat.

scholarly journals Biological Control of Pythium Damping –off in Seedlings with Streptomyces Sp.

2019 ◽  
Vol 8 (4) ◽  
pp. 8035-8039
Keyword(s):  
Biological Control ◽  
Antifungal Activity ◽  
Research Work ◽  
Pythium Aphanidermatum ◽  
Dual Culture ◽  
Damping Off ◽  
Zone Of Inhibition ◽  
Streptomyces Sp ◽  
Rdna Sequencing ◽  
Forest Nurseries

Damping-off is one of the severe diseases caused by soil-borne pathogens notably Pythium sp. the causative agent of this infection in raising tree saplings in forest nurseries. Biological control is an eco-friendly approach in disease management compared to chemical fungicides which in turn affects the soil environment. Biocontrol of Pythium sp. has been emphasized in vegetable nurseries than forest nurseries. The present research work is focused on identification of effective antagonistic organism from forest nursery soils against Pythium aphanidermatum. Bacteria were isolated from various forest soils collected from Boluvampati, Sirumugai and Mettupalayam forest nurseries in Coimbatore district and soil samples were screened for antifungal activity against Pythium aphanidermatum by dual culture technique. Among 245 bacterial isolates, one isolate KUMB1.1 exhibited clear zone of inhibition of 1cm and it was identified by 16S rDNA sequencing as Streptomyces sp. Solvent extraction was performed to isolate an active compound using ethyl acetate, dichloromethane, n-butanol, hexane and chloroform in the ratio 1:1. The antifungal activity of compound was performed by well plate method against Pythium sp. and nbutanol extract exhibited zone of inhibition. The antifungal activity of Streptomyces sp. was tested in a model plant Solanum lycopersicum (Tomato) seeds raised in Pythium aphanidermatum infested soils in seed trays under in vitro conditions. Preemergence and post-emergence disease incidences were observed, and the results exhibited promising efficacy of Streptomyces sp. against the fungal pathogen Pythium aphanidermatum. Seedbed study was carried out in Gmelina arborea seeds, where the seeds are treated with Streptomyces culture broth. In which seed treatment shows 43% increase in germination compared with control.

scholarly journals Streptomyces sp.: Characterization, Identification and Its Potential as a Ralstonia solanacearum Biological Control Agent in vitro

2019 ◽  
Vol 2 (3) ◽  
pp. 89-96 ◽  
Author(s):  
Rachmad Saputra ◽  
Triwidodo Arwiyanto ◽  
Arif Wibowo
Keyword(s):  
Biological Control ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Biological Control Agent ◽  
Wilt Disease ◽  
Molecular Characteristics ◽  
Streptomyces Sp ◽  
Bacterial Wilt Disease ◽  
Wide Range

Streptomyces sp. bacteria have the potential to produce antibiotic compounds, which are one of the mechanisms that are widely used in biological control. However, in general, biological control mechanisms also occur through competition, cell wall degradation and induced resistance. This study was aimed to determine the physiological, biochemical and molecular characteristics of two isolates of Streptomyces sp. (S-4 and S16 isolates) isolated from the tomatoes roots, and to find out their ability to control Ralstonia solanacearum, which causes bacterial wilt disease on a wide range of hosts. The results showed both Streptomyces sp. isolates had several different physiological and biochemical characteristics and had a different ability to inhibit R. solanacearum in vitro. Streptomyces sp. S-16 isolate had a high similarity with Streptomyces diastaticus subsp. ardesiacus strain NRRL B-1773T based on the molecular identification results. Further research needs to be done to see the potential inhibition of the two Streptomyces isolates in inhibiting the development of bacterial wilt disease in tomato plants caused by R. solanacearum.

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