Diplodia Stem Canker and Die-back of Casuarina equisetifolia in Puerto Rico

1969 ◽  
Vol 57 (3) ◽  
pp. 255-261
Author(s):  
Lii-Jang Liu ◽  
Luis F. Martorell
Keyword(s):  
Puerto Rico ◽  
Benzoic Acid ◽  
Mycelial Growth ◽  
Stem Canker ◽  
Casuarina Equisetifolia ◽  
Causal Organism ◽  
Puncture Technique

Diplodia natalensis was isolated from the diseased cankers of Casuarina equisetifolia in Puerto Rico. A stem-puncture technique was employed to inoculate Casuarina seedlings. Sunken areas or cankers appeared on the bark 3 months after inoculation. The causal organism was reisolated. Among the fungicidal chemicals tested (Dithane M-45, Thiodan, Captan, Benlate and benzoic acid), Benlate seemed to be the most promising for inhibiting mycelial growth of D. natalensis in vitro.

scholarly journals Rice Blast in Puerto Rico

1969 ◽  
Vol 62 (3) ◽  
pp. 290-300
Author(s):  
Lii-Jang Liu
Keyword(s):  
Puerto Rico ◽  
Rice Straw ◽  
Rice Blast ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Pyricularia Oryzae ◽  
In Vitro Tests ◽  
Optimum Temperature ◽  
Pathogenicity Tests

Rice blast, which had not been observed during the last six decades in Puerto Rico, reappeared recently in Manatí and in the Gurabo Substation, affecting Brazos, a cultivar introduced from Texas. Pathogenicity tests, as well as studies on the conidial morphology, showed that the fungus isolated from typical blast lesions is Pyricularia oryzae Cav. The physiology of the fungus and its sporulation on various media also were studied. The optimum temperature range, both for mycelial growth and for germination of conidia, was found to be between 24 to 28° C. Sporulation occurred satisfactorily on potato-dextrose agar enriched with coconut milk, and on steamed corn and barley, and rice-straw-decoction agars. In vitro tests with fungicides benomyl, pentachloronitrobenzene, mancozeb, chloroneb, and captan indicated that the first two compounds are the most effective in inhibiting mycelial growth of P. oryzae.

Organic and inorganic nitrogen effects on spore production and mycelial growth of Neonectria ditissima in vitro

2018 ◽  
Vol 71 ◽  
pp. 354
Author(s):  
Rebecca E. Campbell ◽  
Amandine Touron ◽  
Monika Walter
Keyword(s):  
Mycelial Growth ◽  
Morphological Changes ◽  
Inorganic Nitrogen ◽  
Spore Production ◽  
In Planta ◽  
Inorganic N ◽  
Causal Organism ◽  
N Sources ◽  
Plant Pathogen Interaction

Nitrogen (N) is known to influence the growth of Neonectria ditissima (N.d.), the causal organism of European canker. In vitro, inorganic N inhibits conidia germination at N concentrations above 0.2 mol/L while, in planta, foliar urea application increased disease expression of leaf scar wounds up to nine-fold. The influence of organic and inorganic N sources on mycelial growth and spore production of N.d. in vitro was investigated. Four organic and six inorganic N sources were tested on agar at concentrations of N between 0 and 0.2 mol/L, with 3 different N.d. isolates. Spore production was generally increased by the addition of low concentrations of N, with varying results at higher concentrations dependent on the N source; however, this also differed among N.d. isolates. Spore production was generally incompletely inhibited at the higher N concentrations tested. However, germination from the resulting conidia decreased, possibly due to morphological changes to the spores. Mycelial growth generally decreased with the addition of N. Understanding the N effect in planta will be further complicated by the physiological plant-N and plant-pathogen interaction processes.

scholarly journals In vitro evaluation of fungicides and biocontrol agents for efficacy against Neofusicoccum spp that cause dieback of blueberries

2014 ◽  
Vol 67 ◽  
pp. 323-323
Author(s):  
K.M.S. Tennakoon ◽  
H.J. Ridgway ◽  
E.E. Jones ◽  
M.V. Jaspers
Keyword(s):  
Mycelial Growth ◽  
Germ Tube ◽  
Stem Canker ◽  
Conidial Germination ◽  
Biocontrol Agents ◽  
Dual Plate ◽  
Twig Blight ◽  
Different Parts ◽  
Germ Tube Elongation

Several botryosphaeriaceous species have been reported to cause stem canker twig blight and dieback of blueberries with different Botryosphaeria species reported in different parts of the world This research evaluated nine fungicides for their ability to reduce mycelial growth conidial germination and germ tube elongation of four common and pathogenic botryosphaeriaceous species recovered from New Zealand blueberries Furthermore two biocontrol agents were tested against the same species using dual plate assays Fludioxonil carbendazim flusilazole and tebuconazole were the most effective for inhibition of mycelial growth of three isolates each of Neofusicoccum australe N luteum N parvum and N ribis EC50 values for these fungicides were less than 01 mg ai/litre Carbendazim and iprodione (both EC50 004 mg/litre) were the most effective for reduction of conidial germination of all four species In addition these two fungicides were effective for inhibition of germ tube elongation with mean EC50 values of 004 and 01 mg/litre respectively The biocontrol agents Trichoderma atroviride and Bacillus subtilis reduced mycelial growth of all species tested with a range of macroscopic interactions This study has indicated the most promising fungicides and biocontrol agents for further investigations to protect pruning wounds in blueberries

Sexual Compatibility, Morphology, Physiology, Pathogenicity and in vitro Sensitivity to Fungicides of Thielaviopsis paradoxa Infecting Sugarcane and Pineapple in Puerto Rico

1969 ◽  
Vol 57 (2) ◽  
pp. 117-128
Author(s):  
Lii-Jang Liu ◽  
A. Rodríguez Marcano
Keyword(s):  
Puerto Rico ◽  
Benzoic Acid ◽  
In Vitro Tests ◽  
Relative Toxicity ◽  
In Vitro Sensitivity ◽  
Sexual Compatibility ◽  
Rot Disease ◽  
Ceratocystis Paradoxa ◽  
Cultural Media

A previously unreported race of Thielaviopsis paradoxa was isolated from pineapple fruits with symptoms of black rot disease. Macro- and microconidia resemble in appearance those of T. paradoxa, the causal agent of the pineapple disease of sugarcane. Perithecia were produced in PDA (24°-28° C.) when the pineapple isolate was crossed with the light strain of T. paradoxa from sugarcane. Perithecia are characteristic of Ceratocystis paradoxa (horn-like appendages on the base of the perithecia and long, pointed ostiolar hyphae) and are morphologically indistinguishable from those obtained by crossing two sexually compatible strains from sugarcane. However, the rate of growth of the pineapple isolate, under various temperatures, pHs, and cultural media, was consistently different from those characterizing other strains of the fungus. The pineapple strain attacks sugarcane seedpieces more virulently than isolates obtained from sugarcane. In vitro tests were conducted in the laboratory to determine the relative toxicity of the fungicides benzoic acid, Dowicide A, Benlate, Tecto 60 (TBZ), and Dithane M-45 on pineapple and sugarcane isolates of the fungus. Benzoic acid and Dowicide A appeared to be the most effective of these fungicides for inhibiting mycelial growth of T. paradoxa.

scholarly journals Antifungal activity of selected plant extracts against Trichothecium roseum (Pers.) Link (1809) (Sordariomycetes: Hypocreales), causal organism of fungal rot of Solanum melongena L. (Solanales: Solanaceae) in Kashmir, India

2019 ◽  
Vol 6 (12) ◽  
pp. 123-132
Author(s):  
Jahangir Abdullah Koka ◽  
Abdul Hamid Wani ◽  
Mohd Yaqub Bhat ◽  
Shazia Parveen ◽  
Mohammad Afaan Fazili ◽  
...  
Keyword(s):  
Plant Extract ◽  
Plant Extracts ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Solanum Melongena ◽  
Causal Organism ◽  
Trichothecium Roseum ◽  
Egg Plant

Egg plant Solanum melongena L. (Solanales: Solanaceae) is an important vegetable grown in Kashmir. It is attacked by number of fungal pathogens in storage and in the field. These fungi caused several fungal rot diseases resulting heavy losses to the growers. Therefore, present study was carried out to study the incidence and management of fungal rot of egg plant using some selected plant extracts. It was revealed from the study that Trichothecium roseum (Pers.) Link (1809) (Sordariomycetes: Hypocreales) causing decaying of egg plant under storage. Study was also undertaken to evaluate the efficacy of some plant extract against Trichothecium roseum on inhibition of spore germination and mycelial growth under in vitro conditions. It was observed from the results that amongst the plant extracts, plant extract of Ajuga bracteosa at highest concentration was found most effective against Trichothecium roseum and cause highest inhibition in the mycelial growth and spore germination followed by plant extract of Taraxicum officinale, Mentha arvensis and Iris kashmiriana at the same concentrations. Other concentrations of plant extracts also bought about significant reduction in mycelial growth and spore germination of the test fungus but to a lesser extent as compared to control.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

Management of collar rot disease in chickpea by Trichoderma species

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
PREM PANDEY ◽  
G. C. SAGAR ◽  
SUNDARMAN SHRESTHA2 ◽  
HIRAKAJI MANANDHAR ◽  
RITESH K. YADAV ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Maximum Growth ◽  
Pot Experiment ◽  
Trichoderma Spp ◽  
Trichoderma Species ◽  
Collar Rot ◽  
Rot Disease

Nine isolates of Trichoderma spp. were isolated from different agro- ecological regions of Nepal viz; Jumla, Palpa, Chitwan, Tarahara, Banke, Illam and Salyan and screened against Sclerotium rolfsii Sacc. Adreded soil borne phytopathogen causing collar rot of chickpea in chickpea; In-vitro efficacy of nine fungal antagonist (Trichoderma spp.) against Sclerotium rolfsii were screened. Pot experiment was done to find out the effective management of S. rolfsi through Tricoderma using different methods i.e. Seed treatment, soil drenching and soil application. All the tested isolates of Trichoderma spp. were found effective on mycelial growth inhibition and sclerotial parasitization of S. rolfsii. Trichoderma isolated from Palpa district showed maximum growth inhibition (%) of pathogen periodically after 48(93.78%), 72(96.00%), 96(97.96%) and 120(100.00%) hours of inoculation. Parasitized sclerotium showed minimum sclerotial germination on agar plates. Moreover, Trichoderma species isolated from Palpa districts showed second best percent mycelial growth inhibition periodically at 72(25.00%), 120(29.16%), 168(29.16%) and 216(29.16%).In pot experiment at 40 days after sowing, Seedling height was maximum in soil drenching with 30g per 100ml of water (22.27cm) and Mortality percentage of seedlings was least or highest disease control was observed in seed treated with 109cfu/ml (0.000%).

scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

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