scholarly journals Control of Early Blight of Tomato Caused by Alternaria Solani and Screening of Tomato Varieties against the Pathogen

2019 ◽  
Vol 13 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Chapol K. Roy ◽  
Nafiza Akter ◽  
Mohammad K.I. Sarkar ◽  
Moyen Uddin Pk ◽  
Nadira Begum ◽  
...  

Introduction:Early blight is a common disease of tomato, which is caused byAlternaria solani.Objectives:This work was accompanied to find an alternative to chemical fungicides and to screen tomato varieties againstAlternaria solani.Methods:The infected leaves were collected from five tomato fields of Shere-e-Bangla Agricultural University, Dhaka and were cultured for the identification of the infectious fungus and The phytobiocidal role of six plants againstAlternaria solaniwas evaluatedin vitromodel.Results & Discussion:Alternaria solaniwas identified as the infectious fungus. The growth of the test fungiTrichodermaspp.viz.,Trichoderma viride,T. harzianumcollected form NAMDEC andTrichodermasp collected from field of BCSIR was monitored as optimum PH. All the selectedTrichodermaspp. were antagonistic toA. solani.Antagonistic capacity of theTrichodermaspp. was tested by dual culture, volatile as well as non-volatile method. It was observed,T. viridewas most effective in the reduction process ofA. solaniandT. harzianum.T.viridealso showed highest inhibition in volatile and non-volatile trials. Six plant extractsviz.,Adhatoda vasica(Nees),Azadirachta indica(A Juss).Ocimujm sanctum(L),Allium sativum(L),Datura metal(Linn) andZingiber officinale(Rose) were selected to evaluate theirin vitroefficacy of 5%, 10% and 20% concentration against theA. solani.Allium sativumwas the most effective one againstA. solani, followed byAzadirachta indica. The efficacy of five fungicidesviz., Bavistin 50WP, Mancozeb 80WP, Indofil M-45, Sulcox 50WP and Tall 25EC were evaluated for their fungitoxicity against theA. solaniat 100, 200,100, 600 and 800 ppm. Tall 25EC was the most effective fungicide againstAlternaria solanifollowed by Mancozeb 80WP. After screening the five tomato varieties againstA. solani, it was revealed that BARI Tomato-9 had the highest Percentage of Disease Index (PDI) and the leaf of BARI Tomato-7 had the lowest Percentage of Disease Index (PDI).Conclusion:The extract ofAllium sativumwas effective to controlAlternaria solaniat prescribed concentration. The highest PDI was found in BARI tomato-9 againstAlternaria solani.

Author(s):  
Meseret Tadelo ◽  
Tamirat Wato ◽  
Tilahun Negash

Background: Tomato (Lycopersicon esculentum Mill.) belongs to the family Solanaceae. In Ethiopia, control of early blight is largely dependent on fungicidal application. There is a research need to identify effective botanical extracts to control Alternaria solani that cause early blight of tomato and for evaluation of plant extracts through different solvents on the target pathogen. Methods: In vitro experiment was conducted to evaluate the effectiveness of crude extracts of 16 selected medicinal plants against Alternaria solani. Thus, crude extracts were extracted from medicinal plants with different solvents (methanol, ethanol and petroleum at (25%, 50% and 100%) concentrations. The Alternaria solani was isolated from infected tomato leaves showing early blight symptoms. Evaluation of plant extracts was carried out against Alternaria solani using food poisoned technique on PDA. Result: Results showed that most of the methanolic extract plants were showed significant inhibition of the mycelial growth as compared to ethanolic and petroleum ether extracts. A higher rate of mycelial reduction was recorded by ethanol extracts of Allium sativum at all concentrations (100%) followed by methanol extracts of Allium sativum at 25%, 50%, 100% concentration (90.02%, 97.01%, 100% respectively). The effectiveness of extracts against Alternaria solani depends on use at the higher concentrations and various solvents. For crude extracts that have shown higher inhibitory effects against Alternaria solani in vitro conditions, actual chemical compounds should be identified. Furthermore, it is also important to evaluate these plants on other microbes, study to test in vivo and to assess their real potential field condition wherever early blight is an important disease of tomato.


2019 ◽  
Vol 43 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Md Delwar Hosen ◽  
Shamim Shamsi

Four soil fungi were isolated from the soil by serial dilution and were identified as Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. The soil fungi were selected to evaluate their antagonistic potential against seed borne fungus Fusarium merismoides isolated from sesame. In dual culture colony interaction Trichoderma viride showed the highest (45.88%) growth inhibiting effect on F. merismoides followed by A. niger (40.00%), A. flavus (36.37) and A. fumigatus (30.77%). Volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (67.69%) and non-volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (75.00%). Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 17-23, 2019


Author(s):  
Akhilesh Kumar Kulmitra ◽  
Neha Sahu ◽  
V.B. Sanath Kumar ◽  
Thejesha A. G. ◽  
Amlan Ghosh ◽  
...  

The five different bio-agents viz., Trichoderma viride, T. harzianum, T. virens, Pseudomonas fluorescens and Bacillus subtilis were evaluated against Pyricularia oryzae at four and eight days after incubation through dual culture technique. Among the five different bio-agents, highest per cent inhibition of mycelial growth of fungus was recorded in T. virens i.e. 67 per cent and 70 percent after four and eight days after incubation respectively with mean of 68.5 per cent followed by Trichoderma viride with the inhibition of 61 and 63 per cent respectively with mean of 62 per cent. The Pseudomonas fluorescens did not show any inhibition of mycelial growth of P. oryzae as the pathogen over grew the bio-agents.


2021 ◽  
Author(s):  
Vignesh Murthy ◽  
VedhaHari BodethalaNarayanan ◽  
MubarakAli Davoodbasha ◽  
MadhanShankar ShankarRamakrishanan

Abstract A novel strain of Bacillus isolated from rhizosphere has shown to be excellent biocontrol agents against various plant pathogens. In this study, a first report of a Bacillus strain NKMV-3 which effectively controlling Alternaria solani, which cause the Early Blight disease in tomato. Based on the cultural and molecular sequencing of 16S rRNA gene sequence, the identity of the strain was confirmed as Bacillus velezensis NKMV-3. The presence of the lipopeptide which are antibiotic synthesis genes namely Iturin C, Surfactin A, Fengycin B and D were confirmed through gene amplification. In addition, lipopetides was also confirmed through liquid chromatography. The extract showed inhibitory effect against A.solani in-vitro and detached tomato leaf assays. Bacillus velezensis strain NKMV-3 based formulations may provide an effective solution in controlling early blight disease in tomato and other crops.


2021 ◽  
Vol 15 (1) ◽  
pp. 10-20
Author(s):  
Tsegaye Mekuria Ayele ◽  
Guesh Desta Gebremariam ◽  
Subban Patharajan

Introduction: Tomato production in Ethiopia is challenged by many pests and diseases. Fusarium wilt is one of the most important diseases of tomato affecting its productivity. Methods: Tomato tissue and soil samples were collected from tomato farmlands around Aksum town to isolate and identify pathogenic Fusarium species and Trichoderma species with biocontrol efficacy. Samples were processed in the Aksum University Biotechnology laboratory following standard procedures. Results and Discussion: Eight Fusarium and five Trichoderma isolates were obtained. Six of the Fusarium isolates were identified as Fusarium oxysporum, whereas the remaining two were Fusarium equiseti and Fusarium circinatum. Detached leaf bioassay of the F. oxysporum on tomato leaves showed leaf lesion on the tomato variety, Melka oda. The isolated Trichoderma strains were screened for biocontrol potential against virulent F. oxysporum in vitro. The Trichoderma isolate showing the highest biocontrol efficacy against the virulent Fusarium was morphologically identified as Trichoderma viride. in vitro F. oxysporum-T. viride dual culture assay demonstrated that T. viride inhibits the growth of F. oxysporum f.sp. lycopersici with 76.94% growth inhibition. Conclusion: Fusarium oxysporum is prevalent in tomato growing farmlands covered in this study. T. viride identified in this study is an effective biocontrol agent for the identified F. oxysporum fsp. lycopersici in vitro.


2021 ◽  
Vol 50 (2) ◽  
pp. 423-425
Author(s):  
Ramesh Kumar ◽  
Sanjeev Kumar ◽  
Balkishan Chaudhary

Six biocontrol treatments viz., Trichoderma viride, Trichoderma virens, Trichoderma harzianum, T. harzianum + T. viride, T. harzianum + T. virens and T. viride + T. virens were evaluated to test the antagonism against Fusarium verticillioides under in vitro conditions. The maximum growth inhibition (90.6%) was recorded in consortium of T. harzianum + T. viride in dual culture technique . The volatile and non volatile compounds from the consortium of T. harzianum + T. viride also found best and suppressed the mycelial growth of F. verticillioides to the tune of 83.90 and 84.61 %, respectively. Bangladesh J. Bot. 50(2): 423-425, 2021 (June)


2020 ◽  
pp. 1861-1874
Author(s):  
Camila Hendges ◽  
José Renato Stangarlin ◽  
Márcia de Holanda Nozaki ◽  
Eloisa Lorenzetti ◽  
Odair José Kuhn

The early blight (caused by the fungus Alternaria solani) results in significant damage to the tomato crop, directly affecting productivity. An alternative to the frequent use of pesticides is the use of essential oils, which can act in defense against phytopathogens. The objective of this work was to evaluate the toxic activity in vitro of the bergamot orange (Citrus aurantium ssp. bergamia) essential oil against A. solani, the control of the early blight, and the activity of defense enzymes in tomatoes treated with this oil and inoculated with A. solani. Mycelial discs of A. solani were added to dishes with V8 culture media to which essential oil at concentrations of 0, 500, 1000, 1500, 2000, and 2500 µL L-1, in addition to a standard fungicide treatment (azoxystrobin + difenoconazole, 200 + 125 g L-1, respectively) was added. The Petri dishes were incubated at 25 °C in the dark. Mycelial growth was evaluated daily for 19 days, when all treatments reached maximum growth. Sporulation analysis was performed thereafter. Tomato plants were treated with bergamot essential oil, 30 days after transplanting, in the concentrations and fungicide mentioned, in the second pair of leaves. After 72 hours, the pathogen was inoculated using a spray bottle, on treated leaves (second pair of leaves) and untreated leaves (third pair of leaves). The area under the disease progress curve (AUDPC) was calculated based on five severity assessments. The activity of peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) was evaluated in leaves treated with the concentration of 2500 µL L-1 of essential oil. The concentration of 2500 ?L L-1 reduced mycelial growth and sporulation of the pathogen by 68.15% and 29.48%, respectively. In treatments with application of essential oil, lower AUDPC was observed for a concentration of 2500 ?L L-1, which was statistically similar to that observed for fungicide application, both in treated and untreated leaves. A greater activity of PPO, POX, and PAL was found locally and systemically, both in the second and third leaves, at concentration of 2500 ?L L-1. The essential oil of bergamot can be an alternative for the control of early blight in tomato.


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