Studies on the mechanism of fungicidal action of mercuric chloride on mycelial felts of Rhizoctonia solani

1962 ◽  
Vol 43 (4) ◽  
pp. 349-364
Author(s):  
M. K. Tolba ◽  
A. M. Salama
Keyword(s):  
Rhizoctonia Solani ◽  
Mercuric Chloride ◽  
Fungicidal Action

COMPARATIVE EFFECTIVENESS OF SOME ORGANIC AMENDMENTS AND FUNGICIDES IN REDUCING ACTIVITY AND SURVIVAL OF RHIZOCTONIA SOLANI IN SOIL

1962 ◽  
Vol 8 (6) ◽  
pp. 915-922 ◽  
Author(s):  
G. C. Papavizas ◽  
C. B. Davey ◽  
R. S. Woodard
Keyword(s):  
Rhizoctonia Solani ◽  
Active Ingredient ◽  
Comparative Effectiveness ◽  
Organic Amendments ◽  
Cellulose Powder ◽  
N Content ◽  
Fungicidal Action ◽  
Oat Straw ◽  
Reducing Activity

Cellulose powder, oat straw, and soybean hay enriched with NH4NO3 to produce C/N ratios of 60, 30, and 10, respectively, were just as effective as the fungicide PCNB and more effective than the fungicides H 3944 and CP 30249 in reducing the saprophytic activity of Rhizoctonia solani in artificially infested non-sterilized soils 4 weeks after incorporation. One week after incorporation only oat straw and the three fungicides at 50 and 100 p.p.mf. of the active ingredient reduced R. solani activity appreciably. The effectiveness of CP 30249 and PCNB in reducing the saprophytic activity of 5 R. solani clones in soil depended on the fungicide and inoculum concentrations and on the different sensitivities of the clones. Oat straw with C/N ratios of 30 and 80 was more effective in reducing the survival of R. solani in precolonized substrate segments than oat straw with C/N ratio 10 and PCNB at 25 and 50 p.p.m. High decolonizing ability of oat straw with low N content was associated with increased numbers of actinomycetes and bacteria in soil. The sensitivity of R. solani to amendment decomposition and fungicidal action was greater before the fungus saprophytically colonized the substrate than after it became established within the substrate.

scholarly journals Trichoderma harzianum-Mediated ZnO Nanoparticles: A Green Tool for Controlling Soil-Borne Pathogens in Cotton

2021 ◽  
Vol 7 (11) ◽  
pp. 952
Author(s):  
Shimaa A. Zaki ◽  
Salama A. Ouf ◽  
Fawziah M. Albarakaty ◽  
Marian M. Habeb ◽  
Aly A. Aly ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rhizoctonia Solani ◽  
Trichoderma Harzianum ◽  
Pathogenic Fungi ◽  
Macrophomina Phaseolina ◽  
Vitro Assay ◽  
Fungicidal Action ◽  
X Ray ◽  
Soil Borne Pathogens ◽  
Fusarium Sp

ZnO-based nanomaterials have high antifungal effects, such as inhibition of growth and reproduction of some pathogenic fungi, such as Fusarium sp., Rhizoctonia solani and Macrophomina phaseolina. Therefore, we report the extracellular synthesis of ZnONPs using a potential fungal antagonist (Trichoderma harzianum). ZnONPs were then characterized for their size, shape, charge and composition by visual analysis, UV–visible spectrometry, X-ray diffraction (XRD), Zeta potential, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The TEM test confirmed that the size of the produced ZnONPs was 8–23 nm. The green synthesized ZnONPs were characterized by Fourier transform infrared spectroscopy (FTIR) studies to reveal the functional group attributed to the formation of ZnONPs. For the first time, trichogenic ZnONPs were shown to have fungicidal action against three soil–cotton pathogenic fungi in the laboratory and greenhouse. An antifungal examination was used to evaluate the bioactivity of the mycogenic ZnONPs in addition to two chemical fungicides (Moncut and Maxim XL) against three soil-borne pathogens, including Fusarium sp., Rhizoctonia solani and Macrophomina phaseolina. The findings of this study show a novel fungicidal activity in in vitro assay for complete inhibition of fungal growth of tested plant pathogenic fungi, as well as a considerable reduction in cotton seedling disease symptoms under greenhouse conditions. The formulation of a trichogenic ZnONPs form was found to increase its antifungal effect significantly. Finally, the utilization of biocontrol agents, such as T. harzianum, could be a safe strategy for the synthesis of a medium-scale of ZnONPs and employ it for fungal disease control in cotton.

EFFECTIVENESS AND COMPATIBILITY OF FUNGICIDES, INSECTICIDES, AND STARTER SOLUTIONS APPLIED JOINTLY TO CAULIFLOWER

1969 ◽  
Vol 49 (1) ◽  
pp. 39-47 ◽  
Author(s):  
D. G. Finlayson
Keyword(s):  
Rhizoctonia Solani ◽  
Mercuric Chloride ◽  
Plasmodiophora Brassicae ◽  
Sandy Loam ◽  
Peat Soil ◽  
Early Growth ◽  
Organophosphorus Insecticides ◽  
Hylemya Brassicae

Insecticides alone or combined with fungicides and acidic or basic starter solutions were applied to cauliflower in the transplant water to determine their compatibility for control of Hylemya brassicae (Bouché), Plasmodiophora brassicae Wor. and Rhizoctonia solani Kuhn. Effects were assessed by periodic counts to determine phytotoxicity, by uprooting wilted plants to determine maggot damage or wire stem (R. solani), by counting marketable and unmarketable heads, and by uprooting the plants at harvest and grading the maggot damage and incidence by clubroot (P. brassicae). Maggot damage was severe in plots without insecticides. Mercuric chloride gave some protection from maggot damage but retarded early growth and was incompatible with the organophosphorus insecticides Birlane, Dasanic, diazînon and Zinophos. Clubroot was more severe in peat soil than in sandy loam, but was unevenly distributed. Many plants that had clubroot and were attacked by maggots still produced marketable heads if they survived for 6 weeks immediately after transplanting. Acidic starter solution with mercuric chloride reduced the percentage head production. Diazinon was the least effective insecticide. The organocarbamate, Furadan, had systemic properties.

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