scholarly journals Development of an Agar Bioassay Sensitivity Test in Alopecurus myosuroides for the Pre-Emergence Herbicides Cinmethylin and Flufenacet

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1408
Author(s):  
Miriam H. Messelhäuser ◽  
Alexander I. Linn ◽  
Anna Mathes ◽  
Bernd Sievernich ◽  
Roland Gerhards

Rapid and reliable tests for pre-emergence herbicide susceptibility in weeds are important to test a wider range of accessions on their baseline sensitivity, as well as to provide information on putative resistance. This study focused on the development of an agar quick test to determine sensitivity differences in Alopecurus myosuroides Huds. to pre-emergence herbicides containing flufenacet and cinmethylin. The new agar quick test and a standardized whole plant pot bioassay were conducted twice in 2019. For both test systems, seeds of 18 populations of A. myosuroides originated from Southwest Germany and Great Britain were used and treated with discriminating rates of herbicides in dose-response studies. After 28 days, the above-ground dry matter of the plants was determined and the resistance factors were calculated. The agar test was able to provide information on the resistance status of the tested biotype within 12 days. All populations did not show reduced sensitivity to cinmethylin. Within three populations, differences in sensitivity levels were observed between the two test systems. As cinmethylin is not yet marketed in Europe, these resistance factors can also be considered as a baseline sensitivity for A. myosuroides. For flufenacet, the resistance factors differed significantly from the whole plant pot bioassay and the agar test for the biotypes A (0.35, 13.1), C (0.56, 13.2), D (1.87, 12.4), E (15.5, 3.5) and H (2.95, 14). It was possible for the most part for the cinmethylin tested populations to confirm the results of the standardized whole plant pot bioassay in the agar bioassay sensitivity tests, and hence create a promising, faster test system.

2016 ◽  
Vol 3 (1) ◽  
pp. 43-48 ◽  
Author(s):  
V. Patyka ◽  
L. Butsenko ◽  
L. Pasichnyk

Aim. To validate the suitability of commercial API 20E test-system (bioMerieux) for the identifi cation and characterization of facultative gram-negative phytopathogenic bacterial isolates. Methods. Conventional mi- crobiological methods, API 20E test-system (bioMerieux) according to the manufacturer’s instructions. Re- sults. The identifi cation results for Erwinia amylovora, Pectobacterium carotovorum and Pantoea agglome- rans isolates were derived from the conventional and API 20E test systems, which, were in line with the literature data for these species. The API 20E test-system showed high suitability for P. agglomerans isolates identifi cation. Although not all the species of facultatively anaerobic phytopathogenic bacteria may be identi- fi ed using API 20E test-system, its application will surely allow obtaining reliable data about their physiologi- cal and biochemical properties, valuable for identifi cation of bacteria, in the course of 24 h. Conclusions. The results of tests, obtained for investigated species while using API 20E test-system, and those of conventional microbiological methods coincided. The application of API 20E test-system (bioMerieux) ensures fast obtain- ing of important data, which may be used to identify phytopathogenic bacteria of Erwinia, Pectobacterium, Pantoea genera.


Plant Disease ◽  
2001 ◽  
Vol 85 (12) ◽  
pp. 1264-1270 ◽  
Author(s):  
K. M. Chin ◽  
M. Wirz ◽  
D. Laird

An ascospore germination method was developed and validated to assess the sensitivity of bulk samples of Mycosphaerella fijiensis to trifloxystrobin. Using this method, the sensitivity of 142 ascospore samples from banana plantations not treated with strobilurins was analyzed to establish a baseline of pathogen sensitivity. A bulk method was utilized for monitoring purposes because it avoids potential complications due to the isolation and propagation of single-spore isolates and enables the testing of larger samples. Following intensive use of strobilurins (6 to 11 applications per year) over 4 years, under conditions of high disease pressure and the absence of sanitary measures at a development site in Costa Rica, bulk samples with 50% effective concentration (EC50) resistance factors (RFs) in excess of 500 compared with the mean baseline sensitivity were detected. Single-ascospore isolates derived from spores germinating at the discriminatory dose of 3 μg/ml were also resistant, suggesting that the frequency of resistant individuals in bulk samples could be estimated from the relative numbers of ascospores growing at this dose. The resistance of selected isolates was confirmed in planta. In vitro tests with four resistant and two sensitive single-ascospore isolates collected from different locations and times indicated possible cross-resistance of trifloxystrobin to azoxystrobin, famoxadone, and fenamidone, but not to propiconazole.


2010 ◽  
Vol 112 ◽  
pp. 63-72 ◽  
Author(s):  
Philippe Evon ◽  
Virginie VanDenBossche ◽  
Pierre-Yves Pontalier ◽  
Luc RIGAL

Biorefinery of sunflower whole plant can be realized using a twin-screw extruder. Thermo-mechanical fractionation and aqueous extraction are conducted simultaneously. A filter section is outfitted along the barrel to collect continuously an extract and a raffinate (cake meal). Oil yield obtained is 53%. Proteins are partly extracted at the same time, just as pectins and hemicelluloses. Protein yield is 46%. Cake meal is relatively moist (66% for the moisture content). It is first dried to make easier its conservation. It is largely composed of lignocellulosic fibres (59% of the dry matter) from depithed stalk. Lipid content is 13% of the dry matter or 35% of the oil in whole plant. Protein content is 7% of the dry matter or 45% of the proteins in whole plant. DSC measurements indicate that denaturation of proteins is almost complete in the cake meal. DMTA spectrum of its milled powder reveals a significant peak at high temperature (between 175 and 200°C). As already observed with industrial sunflower cake meal, it can be associated with the glass transition of proteins. As a mixture of fibres and proteins, the cake meal can be considered as a natural composite. It is successfully processed into biodegradable and value-added agromaterials by thermo-pressing. As for DMTA analysis, the glass transition of proteins in the cake meal is also observed with PVT analysis at around 180°C. It makes easier the choice of the best thermo-pressing conditions to produce panels with higher mechanical properties in bending. These properties increase simultaneously with temperature, pressure and time chosen for molding operation. The highest flexural strength at break (11.5 MPa) and the highest elastic modulus (2.22 GPa) are obtained for the next molding conditions: 200°C and 320 kgf/cm2 during 60 s. Drop angle measurements show that the corresponding panel is also the most resistant to water. No significant transition is observed inside this panel above 0°C and until 200°C with DMTA analysis. Proteins ensure the agromaterial cohesion without any phase change in this temperature range, and fibres entanglement also acts like reinforcement. This panel could be used as inter-layer sheets for pallets or for the manufacturing of biodegradable containers (composters, crates for vegetable gardening) by assembly of panels.


1987 ◽  
Vol 67 (2) ◽  
pp. 557-562 ◽  
Author(s):  
E. V. VALDES ◽  
R. B. HUNTER ◽  
G. E. JONES

A comparison of two near infrared (NIRA) calibrations (C1 and C2) for the prediction of in vitro dry matter digestibility (IVDM) in whole-plant corn (WPC) was conducted. C1 consisted of 40 WPC samples collected from four locations across Ontario (Brucefield, London, Guelph and Elora). C2 consisted of 90 samples and included the above locations plus Pakenham and Winchester. Nine wavelengths were used in both equations but only three were common in C1 and C2 equations. These wavelengths were 2139 nm, 2100 nm, and 1445 nm, respectively. The predictions of IVDM utilizing both C1 and C2 were good. Coefficients of determination (r2) and standard error of the estimate (SEE) for calibration and prediction sets were 0.91, 1.7; 0.85, 1.7 for C1 and 0.88, 1.6; 0.77, 1.6 for C2 respectively. Regression analysis within location, however, showed low r2 values for the prediction of IVDM for Pakenham and Winchester in both calibrations. The more mature stage of harvest at these locations might be the cause of the poorer predictions. Key words: In vitro digestibility, whole-plant corn, near infrared reflectance


1988 ◽  
Vol 47 (1) ◽  
pp. 105-110 ◽  
Author(s):  
P. K. Bhargava ◽  
E. R. Ørskov ◽  
T. K. Walli

AbstractExperiments were made to study the proportion, chemical composition, and rumen degradability of the morphological components of barley straw (Corgi variety) and to study the selection of these components by sheep. The proportions in the harvested straw dry matter (DM) as leaf blade, leaf sheath, stem and chaff were 128, 314, 500 and 58 g/kg DM, respectively. The different components of straw on analysis proved to have very different concentrations of nitrogen and neutral-detergent cellulase digestibility. The leaf blades had the highest and the stems the lowest values. The degradabilities of DM in the components and in the whole straw were determined by measuring DM loss from samples incubated in nylon bags for various periods in the rumen of sheep. Responses were measured using the mathematical model p = a+b (1–e−ct) where p is DM loss, (a+b) potential degradability, c the rate constant of DM loss and t is the time of incubation. DM losses decreased in the order leaf blades > leaf sheath > whole plant > chaff > stems. Leaf blades also had the highest potential degradability and rate of degradation.In another trial, five sheep were offered unchopped barley straw ad libitum. There were five treatment periods in which sheep were allowed to leave uneaten proportionately 0·2, 0·3, 0·4, 0·5 and 0·7 of the straw on offer for assessing the animal's selection of the morphological components of that straw. The amount of leaf blade in the material consumed increased in largely a linear (P < 0·01) fashion with the amount of excess allowance. The proportion of stem eaten varied conversely. The selection of leaf sheath was less apparent. Little stem was consumed until the proportion of leaf blade in the food available decreased below proportionately 0·4. The practical significance of the study is discussed.


1959 ◽  
Vol 52 (2) ◽  
pp. 230-237 ◽  
Author(s):  
D. J. C. Jones

1. Four varieties of marrow stem kale, three of thousand headed kales, Hungry Gap Kale and Rape-Kale were grown at three centres in mid-Wales. They were sampled in the early winter period and separate leaf and stem samples analysed for the proximate constituents and minerals.2. Leaf to stem ratios were measured on both a green and dry matter basis and the latter values used to calculate whole plant values for the chemical constituents.3. The leaves of the marrow stem kales were higher in dry matter than the stems, except in the case of the Purple Stem Kale. This variety resembled the thousand headed and rape-type kales in having a higher dry matter in the stems. On a dry matter basis, the leaves of all the varieties were richer than the stems in ether extract, crude protein, total ash and all the minerals except potassium and sodium. These elements occurred to a greater extent in the stems of the fleshy stemmed marrow stem kales than in the leaves. The stems were higher in crude fibre and nitrogen-free extractives.4. The leaves of the rape-type kales were higher than those of the other varieties in silica, phosphorus and potassium. They were the best source of phosphorus on a whole plant basis. The marrow stem kales had considerably higher leaf and stem values for sodium and were markedly superior to the other varieties as a source of the element.


2017 ◽  
Vol 48 (2) ◽  
pp. 47-53
Author(s):  
J. Hakl ◽  
R. Loučka ◽  
J. Jirmanová ◽  
V. Jambor

Abstract Maize genotype selection represents a practical tool influencing forage yield and quality. The main objective was to investigate the contribution of genotype, site, and year to variability of maize yield and quality in the environment of Central Europe. Totally 63 maize genotypes at 11 sites over a 7-year period were evaluated for dry matter yield (DMY), dry matter content (DM), starch, cob, neutral detergent fibre (NDF), in situ digestibility of stover NDF (NDFD), and organic matter (OMD). The genotype showed the highest variability from all factors where stover NDFD varied from 261 to 529 g kg-1 and stover OMD from 376 to 609 g kg-1. In contrast to the whole-plant, variability of stover traits was more closely related to NDF than the DM content. Under standardized plant DM, all tested factors were significant and allowed interpretation of 70 and 60% of total variation of yield and quality for stover and whole plant, respectively. The average contributions of genotype, site, and year were 30, 7, and 5%, respectively. For variability in plant productivity and nutritive value, the importance of maize genotype selection was more than two times higher than the contribution of environment.


2006 ◽  
Vol 4 (1) ◽  
pp. 22-27
Author(s):  
Petimat M Djambetova ◽  
Nina V Reutova

The plant test system soybean (Glycine max. (L.) Merill) line T219 turned out to be more sensitive than standart Ames test for evaluation of the mutagenic effect of soil, contaminated by products of combustion and domestic cottage processing of oil. It is preferable to use plant test systems for such investigations because they are more sensitive, simple and inexpensive in comparison with microbial ones.


2016 ◽  
Vol 3 ◽  
pp. 48
Author(s):  
Carlos Rodríguez ◽  
Juan A. Quiñones ◽  
Rodrigo Arias

The trial was conducted at the Centro de Producción Agrícola of ICfA in Cuyuta, Escuintla-Guatemala in order to generate information on the yield and quality of edible mulberry (Morus sp.) roughage treatments consisted of three harvest frequencies (6; 9 and 12 weeks and three fertilization levels of nitrogen (0.40 and 80 kg/ha). A complete randomized block experimental design, with a factorial arrangement (3x3) was used. The cutting height was 0.3 m above the ground level with two sequencies: from August 2nd to September 13 th and from September 13th to December 6th, 1990. In both cases, the 12 week frequency cutting and 80 kg of N were superior to the others (P<=0.01), yielding 6.87 and 6.15 t/ha of dry matter respectively. The yields at 9 weeks were statistically higher than those at 6 weeks. The highest protein percentage of the whole plant, leaves and stalks were produced at 6 weeks. The dry matter digestibility values in vitro showed little variability among treatments, with averages for whole plants, leaves and stalks of 65, 91 and 41 %, respectively. The preceeding data suggests that the mulberry has an excellent potential as a balanced supplement (protein and energy) for dual purpose cattle on the Southern coast of Guatemala.


1986 ◽  
Vol 43 (2) ◽  
pp. 351-354 ◽  
Author(s):  
J. J. Parkins ◽  
R. G. Hemingway ◽  
J. Fraser

ABSTRACTSugar-beet pulp as normally produced in Great Britain contains about 400 g molasses per kg dry matter (DM). It has been demonstrated that either a reduction in the amount or even the full removal of the molasses did not affect the yield or composition of the milk of cows (e.g. Ronning and Bath, 1962; Hemingway, Parkins and Fraser, 1986). The dried, shredded pulp without molasses was, however, generally less palatable.


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