scholarly journals Effects of single and combined inoculations of selected Trichoderma and Bacillus isolates on growth of dry bean and biological control of Rhizoctonia solani damping-off

2011 ◽  
Vol 10 (44) ◽  
pp. 8746-8756 ◽  
Author(s):  
S Yobo K ◽  
D Laing M ◽  
H Hunter C
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Damping Off ◽  
Dry Bean

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.

Mechanism of seedling protection induced by a hypovirulent isolate of Rhizoctonia solani

1989 ◽  
Vol 67 (7) ◽  
pp. 2135-2141 ◽  
Author(s):  
B. Sneh ◽  
M. Ichielevich-Auster ◽  
Z. Plaut
Keyword(s):  
Biological Control ◽  
Cell Wall ◽  
Plant Growth ◽  
Rhizoctonia Solani ◽  
Growth Response ◽  
Damping Off ◽  
Produce Cell ◽  
Protected Plants ◽  
Hypovirulent Strain ◽  
Seedling Protection

Among several hypovirulent isolates of Rhizoctonia spp. tested, one isolate (No. 521) provided significantly higher protection (76–94%) to radish and cotton seedlings against infection by virulent isoltes of Rhizoctonia spp. and also induced a higher increased plant growth response than the others. The hypovirulent strain did not compete for root exudates. The protected plants were not induced to produce new polyphenols, melanins, more lignins, or phytoalexins. Also they did not produce inhibitors of pectinases or cellulases released by the pathogen, nor did they produce cell wall lytic-type enzymes, such as chitinase and β-(1,3) glucanase. Ca2+ content was significantly higher in seedlings colonized by the hypovirulent isolate. The hypovirulent isolate densely colonized the surface of roots and hypocotyls, and removal of its hyphae nullified the protection provided by this isolate. Key words: Rhizoctonia solani, damping-off, hypovirulent isolate, biological control.

scholarly journals Characterization of Genes Involved in Biosynthesis of a Novel Antibiotic from Burkholderia cepacia BC11 and Their Role in Biological Control of Rhizoctonia solani

1998 ◽  
Vol 64 (10) ◽  
pp. 3939-3947 ◽  
Author(s):  
Yaowei Kang ◽  
Russell Carlson ◽  
Wendy Tharpe ◽  
Mark A. Schell
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Burkholderia Cepacia ◽  
Biochemical Characterization ◽  
Genetic Manipulation ◽  
Damping Off ◽  
Control Activity ◽  
Soil Isolate ◽  
Insight Into

ABSTRACT Genetic manipulation of fluorescent pseudomonads has provided major insight into their production of antifungal molecules and their role in biological control of plant disease. Burkholderia cepaciaalso produces antifungal activities, but its biological control activity is much less well characterized, in part due to difficulties in applying genetic tools. Here we report genetic and biochemical characterization of a soil isolate of B. cepacia relating to its production of an unusual antibiotic that is very active against a variety of soil fungi. Purification and preliminary structural analyses suggest that this antibiotic (called AFC-BC11) is a novel lipopeptide associated largely with the cell membrane. Analysis of conditions for optimal production of AFC-BC11 indicated stringent environmental regulation of its synthesis. Furthermore, we show that production of AFC-BC11 is largely responsible for the ability ofB. cepacia BC11 to effectively control the damping-off of cotton caused by the fungal pathogen Rhizoctonia solani in a gnotobiotic system. Using Tn5 mutagenesis, we identified, cloned, and characterized a region of the genome of strain BC11 that is required for production of this antifungal metabolite. DNA sequence analysis suggested that this region encodes proteins directly involved in the production of a nonribosomally synthesized lipopeptide.

scholarly journals Biological Control of Tomato Damping-off Disease Caused by Rhizoctonia solani Kuhn

2019 ◽  
Vol 24 (2) ◽  
pp. 226-237
Author(s):  
Mostafa Amer ◽  
Saad Shama ◽  
Ahmed Heflish ◽  
Mohamed Bresam
Keyword(s):  
Biological Control ◽  
Rhizoctonia Solani ◽  
Damping Off
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