scholarly journals A Mathematical Simulation of Growth of Fusarium in Maize Ears After Artificial Inoculation

2002 ◽  
Vol 92 (5) ◽  
pp. 534-541 ◽  
Author(s):  
D. W. Stewart ◽  
L. M. Reid ◽  
R. W. Nicol ◽  
A. W. Schaafsma
Keyword(s):  
Growth Rates ◽  
Environmental Conditions ◽  
Field Experiments ◽  
Rating Scale ◽  
Fungal Growth ◽  
Weather Conditions ◽  
Fusarium Spp ◽  
Model Calculations ◽  
Maize Hybrid ◽  
Visual Rating

Fusarium spp. in maize can contaminate the grain with mycotoxins if environmental conditions are favorable for fungal growth. To quantify the relationship between growth of Fusarium spp. and environmental conditions, a mathematical model was developed to simulate growth of F. graminearum and F. verticillioides on maize ears following silk inoculation in field experiments from 1992 to 1995. Each species was inoculated separately and as a mixture of the two for 3 of the 4 years on one maize hybrid. Disease progress in ears was measured by a visual rating scale that was converted to percent visual infection. Measurements were made at regular time intervals after silks were inoculated 5 days after silk emergence. Differential equations were used to relate growth rates of Fusarium spp. in maize ears to hourly air temperature and relative humidity and to daily precipitation. Integration of these equations over time produced quantitative estimates of fungal growth. Model calculations compared well with measurements (R2 = 0.931, standard error of estimate [SEE] = 2.11%) of percent visual disease infection of maize ears over 3 years. The model was tested against a second set of data (R2 = 0.89, SEE = 5.9%) in which silks were inoculated at nine different times after first silk emergence for each of 2 years (1994 and 1995) with the two species of fungi on the same maize hybrid. At this time, a silk function was developed to account for changes in the susceptibility of silks to disease. F. graminearum responded to wet conditions more than F. verticillioides, and for the conditions of this experiment, grew much faster than F. verticillioides when inoculated separately. When they were inoculated together, F. graminearum growth rates were much lower, indicating some interference by F. verticillioides. During 1993, weather conditions before inoculation reduced the growth of both species in silks.

scholarly journals HARMFULNESS OF MYCOSISS ON CULTURE OF GARLIC WINTER-ANNUAL IN THE CONDITIONS OF MOSCOW REGION

2018 ◽  
pp. 84-90 ◽  
Author(s):  
T. M. Seredin ◽  
L. I. Gerasimova ◽  
E. G. Kozar ◽  
I. A. Engalycheva ◽  
E. V. Baranova
Keyword(s):  
Storage Time ◽  
Field Experiments ◽  
Weather Conditions ◽  
Moscow Region ◽  
Fusarium Spp ◽  
Mushroom Diseases ◽  
Botrytis Allii ◽  
Winter Annual

One of stressful factors the reducing harvest and quality of bulbs of garlic winter (Allium sativum L.) defeat is diseases of various etiology. Studying of influence of factors of the external environment and stability of a genotype on prevalence of diseases on landings of garlic winter and degree of their injuriousness in the conditions of the Moscow region was the purpose of researches; assessment of collection and selection samples of garlic winter and identification among them steady against the most economically significant diseases. Object of researches were grades and collection samples of garlic of the Federal Scientific Vegetable Center, winter from collections, and other selection institutions. Field experiments and assessment were carried out on a natural infectious background for a number of years. It is as a result established that in the conditions of the Moscow region during vegetation of a plant of garlic winter mainly are surprised mushroom diseases (mycoses) among which the dominating position is taken by fusariosis (micromycetes of the sort Fusarium spp). Defeat of garlic fusariosis is shown annually and with different intensity, depending on weather conditions. The analysis of literature and results of our researches show that number and a ratio of types of Fusarium spp. in a pathogenic complex changes in last years. The types which are earlier not noted on the culture of garlic in the Moscow region (since 2009 – F. avenacium, F. proliferatum, F. subglutinans and F. semitectum are registered; since 2017 – F. gibbosum and F. nivale). In a complex with highly aggressive types of F. solani and F. oxysporum they enhance injuriousness of fuzariosis withering and rots. Mushrooms of the sort Alternaria and other micromycetes of the sorts Stemfillium, Pythium, Embilisia, Verticillum, Cladosporium in the conditions of the Moscow region meet mainly in a complex Fusarium. Gray rot (the activator – Botrytis allii L.) it is more often shown in storage time and transportations of bulbs of garlic. These micromycetes enhance injuriousness of fusariosis and increase losses of a harvest of garlic winter, especially, in the conditions of sharp fluctuations of average daily temperatures and humidity of the soil during the different periods of vegetation. Results of long-term assessment are given in article, grades and perspective collection samples of garlic winter the steadiest against defeat with diseases in the conditions of the changing climate of a zone of Non-Black Earth Region are allocated.

scholarly journals Impact of sowing time, hybrid and environmental conditions on the contamination of maize by emerging mycotoxins and fungal metabolites

2017 ◽  
Author(s):  
Massimo Blandino ◽  
Valentina Scarpino ◽  
Debora Giordano ◽  
Michael Sulyok ◽  
Rudolf Krska ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Field Experiments ◽  
Fusarium Species ◽  
Growing Season ◽  
Fungal Metabolites ◽  
Fusarium Spp ◽  
Sowing Time ◽  
Agronomic Practices ◽  
Growing Seasons ◽  
Late Sowing

Mycotoxins and other fungal metabolites represent the most insidious safety risks to cereal food and the feed chain. Optimising agronomic practices is one of the main strategies adopted to minimise the contents of these undesirable substances in grain-based commodities. The aim of this study was to investigate the effect of the combination of sowing times and hybrids on the occurrence of emerging mycotoxins and fungal metabolites in maize. Field experiments were carried out in 2 sowing times (early vs late) and 3 maize hybrids were compared in the 2014 and 2015 growing seasons. Overall, 37 fungal metabolites produced by Fusarium and Alternaria species were detected. Apart from fumonisins type B (FBs), other metabolites produced by Fusarium verticillioides and F. proliferatum, such as fumonisins type A, fusaric acid, bikaverin and fusaproliferin, were also detected in all of the samples. Fusarin C was found in 61% of the samples. Deoxynivalenol (DON), deoxynivalenol-3-glucoside, culmorin and zearalenone, all of which are produced prevalently by Fusarium graminearum and F. culmorum, were found in all the samples. Their contents were clearly affected by the meteorological trend: the highest contamination was detected in the 2014 growing season, which was characterised by abundant rainfall and lower temperatures from flowering to maize ripening. Among the mycotoxins produced by other Fusarium species, aurofusarin was found to clearly be associated with DON, while moniliformin and beauvericin followed the same behaviour as the FBs. A late sowing time significantly increased the FBs and fumonisin- associated mycotoxins in both growing seasons. The increase in contamination with the delay of sowing was more pronounced in the 2015 growing season, as the environmental conditions were less favourable to the infection of other Fusarium species. The effect of sowing time on DON and DON-associated mycotoxins produced conflicting results for the two growing seasons, because contamination by these metabolites depends more on the conditions that occur during maize flowering than those that occur during ripening. A clearer hybrid susceptibility was observed for these compounds. Other metabolites, such as enniatins, equisetin, T-2 and HT-2 toxins and Alternaria toxins, were always found in traces. The occurrence of these metabolites seems to be influenced less by the considered agronomic practices. The results, obtained under naturally-infected field conditions, underline the key role that the sowing date and hybrid susceptibility play in influencing, in a variable way, the contamination of mycotoxins produced by different Fusarium species in maize subjected to different meteorological conditions. The content of mycotoxins produced by Fusarium spp. section Liseola is more directly and steadily related to late sowing time, while the contamination of mycotoxins associated to Fusarium spp. section Discolor depend more strongly on the environmental conditions at maize flowering and on hybrid susceptibility.

scholarly journals Application of widely used fungicides does not necessarily affect grain yield, and incidence of Fusarium spp. and mycotoxins DON, HT-2 and T-2 in spring barley in northern climates

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Elina Karron ◽  
Eve Runno-Paurson ◽  
Heino Lõiveke ◽  
Bulat Islamov ◽  
Mary-Liis Kütt ◽  
...  
Keyword(s):  
Field Experiments ◽  
Spring Barley ◽  
Weather Conditions ◽  
Kernel Weight ◽  
Fusarium Spp ◽  
Hordeum Vulgare L ◽  
Clear Effect ◽  
The Impact ◽  
Grain Contamination ◽  
Main Factor

Fungicides are widely used to reduce Fusarium infections and grain contamination by mycotoxins and increase the yield in cereals, but the efficacy of fungicide treatments in varying climates has not been systematically explored. Field experiments with Estonian spring barley (Hordeum vulgare L.) cv. ‘Maali’ were carried out in three successive years 2012–2014 with strongly varying weather conditions to study the effects of three fungicides, Folicur (active ingredient tebuconazole), Falcon Forte (prothioconazole, tebuconazole, spiroxamine) and Archer Top (fenpropidin, propiconazole), on the yield, incidence of Fusarium spp. and on the contamination of grain with mycotoxins DON, HT-2 and T-2. The fungicides were sprayed once a year at spring barley flowering time. The weather conditions during the three years of study were extremely different. The content of cycotoxin DON, HT2 and T2 was low. The spraying with fungicides had not a clear effect on the barley yield and 1 000 kernel weight, and the study year was primarily the main factor that affected barley yield (p<0.05) and 1 000 kernel weight (p<0.05). The impact of year together with fungicide treatment had a significant effect on the incidence of Fusarium spp. (p<0.05) and on the incidence of mycotoxin DON in barley kernels (p<0.001), but did not have a clear effect on the incidence of mycotoxins HT2 and T2.

Optimizing genotype-environment-management interactions to ensure silage maize production in the Chinese Maize Belt

2020 ◽  
Vol 80 (2) ◽  
pp. 133-146
Author(s):  
L Zhang ◽  
Z Zhang ◽  
J Cao ◽  
Y Luo ◽  
Z Li
Keyword(s):  
Field Experiments ◽  
Weather Conditions ◽  
Growth Cycle ◽  
High Energy ◽  
Risk Level ◽  
Energy Yield ◽  
Maize Production ◽  
Early Date ◽  
Environment Management ◽  
Silage Maize

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.

The questions of methodology of field experiments in agriculture and crop production

2018 ◽  
Vol 1 (94) ◽  
pp. 38-44
Author(s):  
А.M. Malienkо ◽  
N.E. Borуs ◽  
N.G. Buslaeva
Keyword(s):  
Labor Productivity ◽  
Crop Production ◽  
Field Experiments ◽  
Weather Conditions ◽  
High Accuracy ◽  
Experimental Plot ◽  
Increase Labor Productivity ◽  
Biometric Parameters ◽  
Field Crops ◽  
High Condition

In the article, the results of research on the methodology for conducting studies with corn culture under various methods of sowing and weather conditions. The aim of the research was to establish and evaluate the reliability and high accuracy of the experiment, with a decrease in the area's acreage and taking one plant per repetition. Based on the results of the analysis of biometric parameters and yields, the possibility of sampling from 5 to 108 plants was established statistically and mathematically to establish the accuracy of the experiment. The established parameters of sites in experiments with maize indicate the possibility of obtaining much more information from a smaller unit of area, that is, to increase labor productivity not only with tilled crops. This is the goal of further scientific research with other field crops taking 1 plant of repetitions, observing the conditions of leveling the experimental plot according to the fertility of the soil and sowing seeds with high condition. The data obtained give grounds for continuing research on the minimum space required and the sample in the experiments.

scholarly journals Applications of Chemically Modified Clay Minerals and Clays to Water Purification and Slow Release Formulations of Herbicides

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Tomas Undabeytia ◽  
Uri Shuali ◽  
Shlomo Nir ◽  
Baruch Rubin
Keyword(s):  
Clay Minerals ◽  
Field Experiments ◽  
Slow Release ◽  
Freeze Fracture ◽  
Nano Particles ◽  
Organic Cations ◽  
Small Scale ◽  
High Exposure ◽  
Model Calculations ◽  
Slow Release Formulations

This review deals with modification of montmorillonite and other clay-minerals and clays by interacting them with organic cations, for producing slow release formulations of herbicides, and efficient removal of pollutants from water by filtration. Elaboration is on incorporating initially the organic cations in micelles and liposomes, then producing complexes denoted micelle- or liposome-clay nano-particles. The material characteristics (XRD, Freeze-fracture electron microscopy, adsorption) of the micelle– or liposome–clay complexes are different from those of a complex of the same composition (organo-clay), which is formed by interaction of monomers of the surfactant with the clay-mineral, or clay. The resulting complexes have a large surface area per weight; they include large hydrophobic parts and (in many cases) have excess of a positive charge. The organo-clays formed by preadsorbing organic cations with long alkyl chains were also addressed for adsorption and slow release of herbicides. Another examined approach includes “adsorptive” clays modified by small quaternary cations, in which the adsorbed organic cation may open the clay layers, and consequently yield a high exposure of the siloxane surface for adsorption of organic compounds. Small scale and field experiments demonstrated that slow release formulations of herbicides prepared by the new complexes enabled reduced contamination of ground water due to leaching, and exhibited enhanced herbicidal activity. Pollutants removed efficiently from water by the new complexes include (i) hydrophobic and anionic organic molecules, such as herbicides, dissolved organic matter; pharmaceuticals, such as antibiotics and non-steroidal drugs; (ii) inorganic anions, e.g., perchlorate and (iii) microorganisms, such as bacteria, including cyanobacteria (and their toxins). Model calculations of adsorption and kinetics of filtration, and estimation of capacities accompany the survey of results and their discussion.

scholarly journals Genetic Predisposition to Alzheimer’s Disease Is Associated with Enlargement of Perivascular Spaces in Centrum Semiovale Region

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 825
Author(s):  
Iacopo Ciampa ◽  
Grégory Operto ◽  
Carles Falcon ◽  
Carolina Minguillon ◽  
Manuel Castro de Moura ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Genetic Predisposition ◽  
Rating Scale ◽  
P Value ◽  
Perivascular Spaces ◽  
Centrum Semiovale ◽  
Logistic Regression Models ◽  
Visual Rating ◽  
Increased Risk

This study investigated whether genetic factors involved in Alzheimer’s disease (AD) are associated with enlargement of Perivascular Spaces (ePVS) in the brain. A total of 680 participants with T2-weighted MRI scans and genetic information were acquired from the ALFA study. ePVS in the basal ganglia (BG) and the centrum semiovale (CS) were assessed based on a validated visual rating scale. We used univariate and multivariate logistic regression models to investigate associations between ePVS in BG and CS with BIN1-rs744373, as well as APOE genotypes. We found a significant association of the BIN1-rs744373 polymorphism in the CS subscale (p value = 0.019; OR = 2.564), suggesting that G allele carriers have an increased risk of ePVS in comparison with A allele carriers. In stratified analysis by APOE-ε4 status (carriers vs. non-carriers), these results remained significant only for ε4 carriers (p value = 0.011; OR = 1.429). To our knowledge, the present study is the first suggesting that genetic predisposition for AD is associated with ePVS in CS. These findings provide evidence that underlying biological processes affecting AD may influence CS-ePVS.

scholarly journals Evaluation of Virulence to Adlays of Korean Isolates of Bipolaris coicis Using a Disease Rating Scale

Plant Disease ◽  
2003 ◽  
Vol 87 (6) ◽  
pp. 726-731 ◽  
Author(s):  
Seog Won Chang ◽  
Byung Kook Hwang
Keyword(s):  
Analysis Of Variance ◽  
Environmental Conditions ◽  
Rating Scale ◽  
Leaf Blight ◽  
Reliable Criterion ◽  
Qualitative And Quantitative ◽  
Virulent Isolate ◽  
Geographic Origins ◽  
Disease Rating

The virulence of 33 isolates of Bipolaris coicis from diverse geographic origins in Korea was evaluated on six adlay cultivars or lines under controlled environmental conditions. To evaluate infection levels of B. coicis isolates in adlay plants, a 10-class disease rating scale was developed based on the qualitative and quantitative differences of lesions on adlay leaves infected. There were significant differences in virulence among isolates of B. coicis, although the differences were quantitative rather than qualitative. Significant differences also were observed among cultivar-isolate interactions in the analysis of variance. All isolates of B. coicis, except KG-9515, were pathogenic on adlay plants. BC-20136, the most virulent isolate, was capable of causing highly susceptible reactions on the adlay cultivars or lines. Significant differences in levels of resistance were found among six adlay cultivars or lines tested. The disease rating scale may be a reliable criterion to evaluate a large number of adlays for resistance to leaf blight or B. coicis isolates for virulence to adlays.

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