Evaluation of Microbial Consortia of Trichoderma harzianum and Bacillus amyloliquefaciens for the Management of Groundnut Stem Rot under Controlled Conditions
Jul 2026· Asian Research Journal of Agriculture· 0 citations
TL;DR
Scanning electron micrographs of Sclerotium rolfsii paired with effective Trichoderma and Bacillus isolates showed swollen hyphae with cell-wall damage, providing clear evidence of antagonistic interactions caused by volatile compounds produced by B. amyloliquefaciens and T. harzianum.
Abstract
Groundnut (Arachis hypogaea L.), popularly known as peanut, is one of the most important oilseed and food legume crops cultivated worldwide. However, its cultivation is severely affected by stem rot disease caused by Sclerotium rolfsii, which leads to yield losses of up to 40%. The current study focuses on the management of Sclerotium rolfsii through the combined application of Trichoderma spp. and Bacillus spp. under field conditions. A roving survey conducted in major groundnut-growing areas of Trichy district, Tamil Nadu, revealed varying levels of disease incidence (46.00%–81.00%). The stem rot pathogen and antagonists were isolated from the surveyed locations and identified using morphological characteristics and molecular phylogenetic analyses based on ITS and 16S rDNA sequences, respectively. In vitro dual-plate assays revealed that Bacillus amyloliquefaciens BC-5 and Trichoderma harzianum TR-2 exhibited 82.22% and 86.66% inhibition, respectively, whereas paired-plate assays showed 78.27% and 75.55% inhibition against Sclerotium rolfsii. Scanning electron micrographs of Sclerotium rolfsii paired with effective Trichoderma and Bacillus isolates showed swollen hyphae with cell-wall damage, providing clear evidence of antagonistic interactions caused by volatile compounds produced by B. amyloliquefaciens and T. harzianum. At the field level, the combined application of effective B. amyloliquefaciens and T. harzianum performed better in reducing wilt disease incidence (77.90%) than the individual applications.
Assessment of damage potential and sustainable management options in radish, a highly susceptible, short-duration crop that experiences both foliar and root damage, and the potential of native Beauveria bassiana isolates for integration into sustainable pest management programs highlights the potential of native entomopathogenic fungi for integration into sustainable pest management programs.
Benakashree Chandrakanth, Shanthi Mookiah, M. Marimuthu et al.· Archives of Microbiology· 0 citations
Oilseed brassicas, commonly known as rapeseed–mustard, belong to the family Brassicaceae, which comprises approximately 350 genera and over 3,500 species. Rapeseed–mustard crops are vulnerable to a wide range of pathogens, including fungi, bacteria, viruses, and phytoplasmas. Among these, Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is one of the most destructive fungal diseases affecting Indian mustard, leading to significant yield and economic losses. This study presents a comprehensive review of current disease management approaches emphasizing the use of organic amendments and biological control agents, along with recent advances in eco-friendly practices. Additionally, the research evaluates the efficacy of selected bio agents and organic amendments under both in vitro and in vivo conditions to enhance our understanding of their role in managing Sclerotinia stem rot. The experiment was conducted at the Department of Plant Pathology, Swami Keshwanand Rajasthan Agricultural University, Bikaner. Four bio agents were tested in vitro, while eight organic amendments and bio agent combinations were evaluated in vitro. Among the bio agents tested in vitro, Trichoderma harzianum exhibited the maximum mycelial growth inhibition (68.51%), which was significantly superior to T. viride (61.94%), Pseudomonas fluorescens (24.31%), and Bacillus subtilis (17.66%). Under in vivo conditions, the combined application of Trichoderma harzianum + neem cake demonstrated the highest disease suppression with 74.72% inhibition, followed by Trichoderma harzianum + mustard cake (71.35%). The lowest efficacy was observed with mustard cake alone (32.47%).The findings highlight the potential of bio agents, particularly Trichoderma harzianum, in combination with organic amendments, as effective and sustainable alternatives to chemical fungicides for the management of Sclerotinia stem rot in mustard. The study also outlines future research directions aimed at strengthening eco-friendly disease management strategies for sustainable mustard production.
S. Choudhary, A. L. Yadav, Komal Choudhary et al.· Journal of Eco-friendly Agri...· 0 citations
Stem-end rot (SER) is an important postharvest disease that reduces the quality and marketability of star apple (Chrysophyllum cainito L.), while biological control offers a more sustainable alternative to chemical management. This study aimed to (i) select fungal strains causing SER disease in star apple and (ii) select and appraise strains of Trichoderma spp. fungi as antagonists to the selected fungi causing SER disease under in vitro conditions. Ten fungal isolates were obtained from symptomatic fruits, and 35 Trichoderma isolates were recovered from star apple rhizosphere soils. Five rapidly growing fungal isolates were evaluated using a detached-fruit pathogenicity assay, with three fruits per treatment. The five strains with the strongest expression of SER were selected and identified as Lasiodiplodia theobromae L-SA01, L-SA03, and L-SA07, L. venezuelensis L-SA02, and L. egytiacae L-SA06. Among 25 Trichoderma isolates screened for extracellular enzyme activities, T-SA05, T-SA30, and T-SA32 were selected for broad antagonistic activity and were provisionally associated with T. asperellum, T. yunnanense, and T. viride, respectively. At 72 h, these isolates showed antagonistic efficiencies of 55.4–58.9% against L-SA01, 64.9–69.6% against L-SA02, 80.8–82.4% against L-SA03, 58.6–59.3% against L-SA06, and 49.9–54.1% against L-SA07. L. venezuelensis and L. egytiacae were the two fungal species first found to cause SER. T. yunnanense was recently proven to control the Lasiodiplodia spp. fungi that cause SER. The selected isolates also exhibited chitinase and glucanase activities, although their enzyme profiles did not fully correspond to their antagonistic efficiencies. These findings identify indigenous Trichoderma isolates for further taxonomic confirmation and evaluation in postharvest fruit assays.
K. Nguyen, Trịnh Kim Tú Hoàng, Le Thi My Thu et al.· Horticulturae· 0 citations
To address the need for effective biocontrol of poplar anthracnose caused by Colletotrichum gloeosporioides, in this study, 20 Trichoderma strains were isolated from the rhizosphere of seven tree species on Tianzhu Mountain to screen for potent growth-promoting and antifungal agents. The inhibitory effects of the strains on C. gloeosporioides (Cgl) were evaluated through mycelial growth assays, volatile organic compound tests, and fermentation filtrate analysis, while their growth-promoting capabilities and induction of systemic resistance were assessed in poplar seedlings via biomass measurement, stomatal analysis, and gene expression profiling. The results demonstrated that T. asperelloides Tas369 significantly inhibited pathogen growth and improved seedling growth, increasing stomatal density by 134% and inducing phenylalanine ammonia-lyase (PAL) and peroxidase (POD) enzyme activities. Notably, Trichoderma composite (Tcom) outperformed single-strain treatments, achieving 89.8% control efficacy, reducing the malondialdehyde content by 1.1 mmol/g, and significantly upregulating the key defense genes NPR1 (14.32-fold) and PR1-1 (219.79-fold) through increased activity of the salicylic and jasmonic acid signalling pathways. In conclusion, while Tas369 exhibits strong individual potential, the Tcom consortium provides superior biocontrol through multiple mechanistic interactions, offering an effective and sustainable approach for managing poplar anthracnose in forestry applications.
Ning Kong, Bin Liu, Jing Han et al.· Microorganisms· 0 citations
Groundnut (Arachis hypogaea L.) is an important oilseed crop, but its productivity is affected by stem rot caused by Sclerotium rolfsii Sacc. Biological control using antagonistic fungi offers a potential approach for reducing dependence on chemical disease management. The present study evaluated the in vitro inhibitory activity of cell-free culture filtrates from ten native isolates of Trichoderma viride against S. rolfsii. The pathogen was isolated from infected groundnut stem tissues and identified based on colony morphology and sclerotial characteristics. T. viride isolates were obtained from rhizosphere soil samples and maintained as Tv1 to Tv10. Culture filtrates were prepared from 10-day-old potato dextrose broth cultures and incorporated into potato dextrose agar at 10%, 20%, 30% and 40% concentrations using the poisoned food technique. All isolates reduced radial mycelial growth of S. rolfsii compared with the control and inhibition generally increased with filtrate concentration. Among the isolates tested, Tv4 showed the greatest inhibitory effect, restricting pathogen growth to 27.79 mm, 19.56 mm, 12.26 mm and 0.00 mm at 10%, 20%, 30% and 40% concentrations, respectively. Complete inhibition was observed with Tv4 at a 40% concentration. Tv6, Tv7 and Tv8 also showed high inhibition at the highest concentration. These results indicate that T. viride culture filtrates can suppress S. rolfsii growth under in vitro conditions.
K. Balamurugan, K. Vigneshwaran, R. Livitha· Journal of basic and applied...· 0 citations
The findings provide a theoretical foundation for accurate disease diagnosis, epidemiological surveillance, and the development of effective chemical control strategies for rubber plantations.
Zhiying Cai, Lili He, Li-Ming Dai et al.· Plants· 0 citations