Evaluation of oil suspension emulsions of Colletotrichum orbiculare as a mycoherbicide in field trials (original) (raw)
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Stability of Colletotrichum truncatum in Culture Influences Mycoherbicide Efficacy
Mycologia, 1994
Colletotrichum truncatum, a potential mycoherbicide for control of hemp sesbania, formed spontaneous variants on agar medium. The predominant variant produced more spores than the wild type on potato dextrose agar but the wild type produced more spores on Czapek-Dox agar. Spore yield of both types was greatly reduced on Czapek-Dox. In liquid culture, the variant spontaneously arose and gradually displaced the wild type. Although the variant produced more spores in liquid culture, it had reduced virulence. Displacement of wild type strains by similar variants in liquid fermentation may constrain production of this mycoherbicide and should be considered during the preparation of C. truncatum inocula.
Cellular and Molecular Biology, 2018
Anthracnose of banana is incited by Colletotrichum musae. It is recognized as one the most destructive diseases of mature and immature banana fruits, resulting in huge economic losses all over the world. Present research deals with screening some oils both in vitro and in vivo for their antifungal activity against C.musae. Clove oil (0.1µl/ml) completely arrested the conidial germination and mycelial growth of C. musae. Fenugreek and almond oil exhibited significant inhibition of mycelial growth, 61% and 57% at a concentration of 2µl/ml. However, olive oil was least inhibitory on the test fungi. Clove oil also a showed marked reduction in anthracnose lesions on banana fruits, thereby suggesting disease control. Scanning electron microscopy revealed severely damaged mycelium and conidia. FTIR studies show the presence of important bands representing phenols, terpenes, aldehydes, and ketones. Based on our findings; clove, fenugreek and almond oil demonstrated fungicidal and fungistat...
Biological Potencial of Colletotrichum typhae H.C Greene mycoherbicide for Typha domingensis Pers
The anthropic interference in aquatic ecosystems, favors the disordered colonization of T. domingensis, damaging the production of hydroelectric power and river traffic. Thus, the objective of this study was to evaluate the potential of C. typhae as a mycoherbicide in the control of T. domingensis, in vitro and in greenhouse. 107 samples of symptomatic T. domingensis leaves were collected in flooded areas of rivers in Brazil, with identification and isolation of the collected fungal species. The concentration of inoculum was determined to evaluate the incidence and severity of the disease, the influence of temperature on mycelial growth and conidia germination, the effect of temperature and leaf wetness period on T. domingensis infection by C. typhae and the host range test. The growth of the colonies of C. typhae was higher at 25 to 30 ºC, there was no interference of the photoperiod on germination of the spores, but the highest percentage of germination occurred at 17.39 ºC. The i...
International Journal of Chemical Studies, 2021
Colletotrichum capsici infection will be higher in the mature stage of chilli plant than in the early stage of plant (Krairuan et al., 2008). The fungus prefers warm humid environment for spreading the anthracnose disease uniformly and effectively. All the two contact and six systemic fungicides evaluated in vitro were found fungistatic against Colletotrichum capsici. Among all these fungicides, Tricyclazole was found to be most effective with significantly maximum mycelial growth inhibition and least mycelial growth followed by fungicides viz. Azostrobin, Tebuconazole, Difenconazole, Propiconazole, Carbendazim + Mancozeb. While comparatively minimum average radial mycelial growth inhibition was recorded with Hexaconazole followed by Propineb. All the seven fungal and one bacterial antagonists evaluated in vitro were found antifungal against Colletotrichum capsici exhibited significant mycelial growth inhibition. However, Trichoderma asperallum, Pseudomonas fluorescens, Trichoderma harzianum and Gliocladium virens recorded significantly highest mycelial growth inhibition. Rest of the bioagents, Trichoderma ligronum, Trichoderma koningii and Trichoderma longibrachiatum and Trichoderma hamatum tested also caused significant mycelial inhibition of the test pathogen.
The aim of the present investigation was to evaluate the antifungal activities of bioagents and fungicides which can be used to control bean anthracnose. Three fungicides viz., Mancozeb, Folpan and Mancolaxyl, and three bioagents viz., Trichoderma harzianum Rifai, Trichoderma viride Pers. Fr. and Pseudomonas fluorescens Migula, were screened in vitro for their antifungal activities against common bean anthracnose, C. lindemuthianum using the dual culture and microtitre double-dilution techniques. Antagonistic effects of the three bioagents tested by the dual culture method showed highly significant (P<0.01) percentage of inhibition of the mycelia germination of C. lindemuthianum. The highest percentage of inhibition of the mycelia germination (80.39%) was obtained from T. viride, followed by 75.49% from T. harzianum and 40.2% from P. fluorescens. Similarly, highly significant (P<0.01) differences were observed in the radial growth of mycelia of C. lindemuthianum. The highest growth of mycelia (3.4 cm) was measured from the control (C. lindemuthianum), whereas the least (0.67 cm) was obtained from the dual culture containing T. viride. The in vitro assays revealed that all the antagonistic bioagents produced siderophores which were capable of inhibiting mycelia growth of the pathogen. The mancozeb fungicide was found to be fatal to C. lindemuthianum at four different concentrations poisoned on potato dextrose agar medium.
Biological Control, 2005
The fungus Alternaria eichhorniae isolate #5 (Ae5) is being developed as a mycoherbicide agent for controlling waterhyacinth (Eichhornia crassipes) in Egypt. Inoculum concentrations above 10% (mycelial wet weight) were all equally eVective in controlling waterhyacinth at 100% level (weed kill). Fresher mycelial inoculum (4 weeks old) was more virulent than older inoculum (9 or 16 weeks old). Applications of Ae5 in an aqueous carrier or in nine diVerent oil emulsions were evaluated for the biocontrol of waterhyacinth, without a post-treatment dew period, under natural outdoor conditions. The oil emulsions were developed to provide moisture and to retard evaporation from the applied fungal inoculum so that the fungal propagules could germinate and infect the weed under relatively dry conditions. All of the invert and oil emulsion formulations induced higher levels of disease on waterhyacinth plants than the aqueous formulation under dew-free conditions. Reducing the oil content in the Ae5 emulsion formulation from 30 to 5% had no eVect on the formulation's eYcacy against waterhyacinth. When applied in the winter under natural conditions in Egypt, Ae5 formulated in cottonseed oil emulsion caused 100% control of waterhyacinth in outdoor Weld plots 7-13 weeks after application. Thus, the results conWrm the utility and feasibility of oil emulsions as formulating materials that promote the bioherbicide's activity in the absence of dew. 2004 Elsevier Inc. All rights reserved.
Anthracnose of chilli is one of most important disease causing great economic loss. Anthracnose may cause yield losses up to 50 per cent. There is varied range of chemical fungicides available in the market for controlling this pathogen, viz. Colletotrichum capsici, but the extent of inhibition varies with different fungicides. Five fungicides viz. Kasugamycin (Kasu B 3%SL), Pyraclostrobin + Metaram (Carbrio Top 60%WG), Azoxystrobin (Onestar 23%SC), Fusilazole (Cursor 40%EC) and Carbendazim (Dhanustin 50%WP) were assayed for their efficacy against Colletotrichum capsici by Poison food technique. These fungicides were prepared at two concentrations viz. 250 ppm and 500 ppm concentration, evaluated for their toxicity against Colletotrichum capsici under in vitro condition using poisoned food technique. Under in vitro condition, all the fungicides which were tested against the growth of the fungus Colletotrichum capsici proved to be effective. Carbrio Top 60% WG was found highly effective with mycelia growth inhibition (72.66%) followed by (Azoxystrobin) Onestar 23%SC, (Fusilazole) Cursor 40%EC, (Carbendazim) Dhanustin 50%WP and (Kasugamycin) Kasu B 3%SL at 250 ppm with inhibition percentage of 60.78%, 43.77%, 31.1% and 24.4% respectively. Similar trend were obtained at 500 ppm also, the mycelial inhibition percentages were 81.45%, 72.33%, 66.67%, 52.4% and 35.2% respectively.
February 2020
The anthropic interference in aquatic ecosystems favors the disordered colonization of T. domingensis, damaging the production of hydroelectric power and river traffic. Because of this, studies report the efficacy of fungal mycoherbicides, with control rates reaching as high as 90%. Thus, the objective of this study was to evaluate the potential of C. typhae as a mycoherbicide in bio control of T. domingensis, at in vitro and greenhouse conditions. 107 samples of symptomatic T. domingensis leaves were collected in flooded areas of rivers in Brazil, with identification and isolation of the collected fungal species. The concentration of inoculum was determined to evaluate the incidence and severity of the disease, the influence of temperature on mycelial growth and conidia germination, the effect of temperature and leaf wetness period on T. domingensis infection by C. typhae and the host range test in vitro. The growth of the colonies of C. typhae was higher at 25 to 30 ºC. There was ...