Effect of the fumigant metham on Trichoderma spp.

1984 ◽  
Vol 30 (6) ◽  
pp. 739-745 ◽  
Author(s):  
J. A. Lewis ◽  
G. C. Papavizas

Radial growth of 34 isolates of Trichoderma hamatum, T. harzianum, and T. viride was inhibited (mean effective dose (ED50)) by as little as 1.3 μg of vapors (mostly methylisothiocyanate) per cubic centimeter of atmosphere from metham decomposing in soil suspensions. Isolates of T. hamatum were generally more sensitive than those of T. harzianum to the vapors. Spore germination was more sensitive than hyphal growth to vapors, and whereas the toxic volatiles were only fungistatic to growth, they were fungicidal to germination. As little as 0.5 μg/cm3 of vapors from decomposing metham in soil reduced germination of conidia of three isolates (TMP, Tm-1, and T-1-R4) more than 50% and in another three (T-1, Th-6, and Th-20) 90%. Exposure of spores to metham in solution (350 μg active ingredient/mL) for 1 h reduced survival more than 50% in eight isolates. When conidia of T. viride (T-1-R4) and T. harzianum (WT-6-24) were added (ca. 20 × 103 spores/g) to soil treated with a sublabel rate of metham (equivalent to 234 L/ha), the number of colony-forming units (CFU) of isolates introduced 4 days before, or at time of fumigation were significantly less than those in nonfumigated soil after 3 weeks of incubation. CFU of isolates introduced 4 days after fumigation were similar to those in nonfumigated soils. Over a 9-week period, introduced populations of T-1-R4 and WT-6-24 remained static in nonfumigated soils. Indigenous Trichoderma spp. appeared unaffected by the levels of metham used. Addition of bran or use of soils high in natural organic matter did not affect results.

Plant Disease ◽  
2004 ◽  
Vol 88 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Jessica S. Engle ◽  
Patrick E. Lipps ◽  
Terry L. Graham ◽  
Michael J. Boehm

Fusarium head blight has been more severe when infection occurs during anthesis, indicating that floral organs may be important infection courts. Choline acetate and glycinebetaine have been extracted from wheat and reported to be growth stimulants of Fusarium graminearum. They are hypothesized to enhance infection and tissue colonization. Growth of F. graminearum was examined on media amended with extracts from floral parts of nine wheat genotypes with various Fusarium head blight resistance levels. Results indicated no significant effect of anther, palea, or lemma extracts on radial growth when compared with unamended controls. Effects on spore germination and hyphal growth of F. graminearum by choline, betaine, and an equimolar mixture at concentrations ranging from 0.01 to 1,000 μM also were examined. Spore germination was not significantly (P ≤ 0.05) affected by choline, betaine, or a combination of the compounds compared with unamended controls. Radial hyphal growth also was not consistently affected (P ≤ 0.05) by choline or betaine when compared with controls. Equimolar mixtures of the two compounds showed significant slight reduction in growth rate at higher concentrations when compared with controls. The reduction in growth rate was due to higher concentrations of betaine. Results of this study indicate that endogenous compounds in floral parts may not be associated with wheat resistance to F. graminearum.


2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.


2000 ◽  
Vol 49 (5) ◽  
pp. 269-280 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Ying-Shih Ma ◽  
Guor-Cheng Fang ◽  
Fang-Fong Zing

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.


2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 427-433 ◽  
Author(s):  
J. van Leeuwen ◽  
C. Chow ◽  
R. Fabris ◽  
N. Withers ◽  
D. Page ◽  
...  

To gain an improved understanding of the types of organic compounds that are recalcitrant to water treatment, natural organic matter (NOM) isolates from two drinking water sources (Mt. Zero and Moorabool reservoirs, Victoria, Australia) were separated into fractions of distinct chemical behaviour using resins. Four fractions were obtained from each water source and were organics absorbed to: (1) XAD-8 (very hydrophobic acids, VHA); (2) DAX-4 (slightly hydrophobic acids, SHA); (3) bound to an anion exchange resin (charged organics, CHAR); and (4) not absorbed or bound to resins (neutrals, NEUT). These fractions were then tested to determine the capacity of alum to remove them from water and to correlate this with the character of each isolate. The fractions were characterised by the application of high performance size exclusion chromatography (HPSEC), bacterial regrowth potential (BRP), trihalomethane formation potential (THMFP), pyrolysis gas-chromatography mass spectrometry (Py-GC-MS) and thermochemolysis. The highest removals of dissolved organic carbon (DOC) by alum treatment were in waters spiked with the CHAR fractions while the NEUT fractions were the most recalcitrant. The number average molecular weights (Mn) of DOC of the CHAR fractions before treatment were the highest, whilst those of the NEUT fractions were the lowest. After alum treatment, the Mn of the NEUT fractions were only slightly reduced. Results from Py-GC-MS and thermochemolysis indicate that the NEUT fractions had the highest relative proportion of saccharide derived organic material. Nonetheless, the BRP of waters spiked with the NEUT fractions differed markedly, indicating that organics recalcitrant to alum treatment can vary substantially in their chemical composition and capacity to support microbial growth.


Author(s):  
Chuan-Wang Yang ◽  
Li Yuan ◽  
Hong-Zhi Zhou ◽  
Xin Zhang ◽  
Guo-Ping Sheng

Natural organic matter (NOM) can adsorb onto engineered nanoparticles (ENPs) and form NOM-corona on ENPs-solution interface, thus affecting the performance and ecotoxicity of ENPs in aquatic systems. Nevertheless, the formation...


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 274
Author(s):  
Sara Mayo-Prieto ◽  
Alejandra J. Porteous-Álvarez ◽  
Sergio Mezquita-García ◽  
Álvaro Rodríguez-González ◽  
Guzmán Carro-Huerga ◽  
...  

Spain has ranked 6th on the harvested bean area and 8th in bean production in the European Union (EU). The soils of this area have mixed silt loam and sandy loam texture, with moderate clay content, neutral or acidic pH, rich in organic matter and low carbonate levels, providing beans with high water absorption capacity and better organoleptic qualities after cooking. Similar to other crops, it is attacked by some phytopathogens. Hitherto, chemical methods have been used to control these organisms. However, with the Reform of the Community Agrarian Policy in the EU, the number of authorized plant protection products has been reduced to prevail food security, as well as to be sustainable in the long term, giving priority to the non-chemical methods that use biological agents, such as Trichoderma. This study aimed to investigate the relative importance of various crop soil parameters in the adaptation of Trichoderma spp. autoclaved soils (AS) and natural soils (NS) from the Protected Geographical Indication (PGI) “Alubia La Bañeza—León” that were inoculated with Trichoderma velutinum T029 and T. harzianum T059 and incubated in a culture chamber at 25 °C for 15 days. Their development was determined by quantitative PCR. Twelve soil samples were selected and analyzed from the productive zones of Astorga, La Bañeza, La Cabrera, Esla-Campos and Páramo. Their physicochemical characteristics were different by zone, as the texture of soils ranged between sandy loam and silt loam and the pH between strongly acid and slightly alkaline, as well as the organic matter (OM) concentration between low and remarkably high. Total C and N concentrations and their ratio were between medium and high in most of the soils and the rest of the micronutrients had an acceptable concentration except for Paramo’s soil. Both Trichoderma species developed better in AS than in NS, T. velutinum T029 grew better with high levels of OM, total C, ratio C:N, P, K, Fe, and Zn than T. harzianum T059 in clay soils, with the highest values of cation exchange capacity (CEC), pH, Ca, Mg and Mn. These effects were validated by Canonical Correlation Analysis (CCA), texture, particularly clay concentration, OM, electrical conductivity (EC), and pH (physical parameters) and B and Cu (soil elements) are the main factors explaining the influence in the Trichoderma development. OM, EC, C:N ratio and Cu are the main soil characteristics that influence in T. velutinum T029 development and pH in the development of T. harzianum T059.


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