Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Trichoderma Harzianum WKY1: an indole acetic acid producer for growth improvement and anthracnose disease control in sorghum

Abstract: The efficiency of two isolates of Trichoderma harzianum (WKY1 and WKY5) as bio-control agents against anthracnose disease in sorghum was investigated. In vitro, T. harzianum WKY1 isolate showed superiority in terms of inhibition of both mycelial growth and spore germination of Colletotrichum sublineolum, the causative agent of sorghum anthracnose, as well as induction of the sorghum seed germination over T. harzianum WKY5 isolate. The culture filtrate of the selected isolate (T. harzianum WKY1) was analysed using GC-MS system to determine their chemical constituents. Twenty-nine components with varied existence percentages were identified. Although T. harzianum WKY1 produced the phytohormone indole-3-acetic acid (IAA) on tryptophan free medium, a marked dependency on tryptophan for the production of IAA was noticed. Nutritional components were optimized for maximizing IAA production using the central composite design. The optimum levels were 1.06, 29.86 and 2.93 g L−1 from tryptophan, sucrose and ...

Microbial Toxicity of Pesticide Derivatives Produced with UV-photodegradation

Abstract: Our study aimed at acquiring information about the biological effect of pesticides and their degradates produced by UV-treatment on microbiological activity. Five photosensitive pesticides (carbendazim, acetochlor, simazine, chlorpyrifos, EPTC) and six representative soil microbes (Bacillus subtilis, Pseudomonas fluorescens, Mycobacterium phlei, Fusarium oxysporum, Penicillium expansum, Trichoderma harzianum) were applied throughout our model experiments. The antimicrobial effects of the pesticides and their degradates were assessed with filter paper disk method. The antimicrobial effect of the degradation products exhibited marked differences in terms of pesticide types, irradiation time, and the test organisms. Acetochlor and its photolytic degradation products were found to be more toxic to bacteria than fungi. All the three bacteria proved to be sensitive to the basic compound and its degradation products as well. The end product of carbendazim was weakly antibacterial against P. fluorescens and B. subtilis but strongly antifungal against T. harzianum. Chlorpyrifos and its end product inhibited neither test organisms, but the degradates hindered the growth of four of them. The basic compound of EPTC and the degradates of simazine exhibited significant toxicity to the test bacteria. It might be claimed that the pesticide photodegradation may result in significant changes in soil microbiota, as well as formation of biologically harmful degradates.

Management of stem rot of groundnut caused by Sclerotium rolfsii through Trichoderma harzianum

Abstract: In dual culture of 11 isolates of Trichoderma harzianum, three isolates, viz. T8, T10 and T2, were effective against Sclerotium rolfsii [Corticium rolfsii], the causal agent of stem rot of groundnut, and they overgrew the pathogen up to 92, 85 and 79%, respectively, in vitro. T8 and T10 isolates reduced stem rot incidence significantly when delivered as seed dressing or soil application in pot trials. Disease reduction through seed dressing was 33-50% over control and through direct soil application it was up to 72-83%. Spores of T8 and T10 isolates showed better longevity after 13 weeks (1.3 x 103 cfu/seed) and up to 15 weeks (1.0 x 104 cfu/seed), respectively, when the seeds coated with spores were dipped in 2% carboxy methyl cellulose (CMC) andpelleted with bentonite at 25 g/kg seed. The maximum population was recorded at 30 day after storing (T8 = 3.5 x 106 and T10 = 20.2 x 106). On seed coated with Trichoderma spores infused with 2% CMC and then pelleted with a mixture of Jalshakti (a water-absorbing polymer) at 100 g/kg and bentonite at 25 g/kg seed, Trichoderma remained viable only up to 11 weeks. The spores remained viable only up to 9 weeks of storage at room temperature on seeds when the seeds were coated with biocontrol agent by rolling seeds on a colony of Trichoderma in Petri dishes.