Showing papers on "Rust published in 1990"
TL;DR: In this article, the existence of a thin intermediate layer composed of phosphatic rust was found between the outer and the inner layers showing that phosphorus in steel is converted to phosphatic compound during the protective rust formation.
58 citations
TL;DR: Levels of individual phenolic acids were examined in primary leaves of wheat after inoculation with avirulent and virulent strains of the leaf rust fungus at stages when previous work had shown fungal and host cells to be affected by expression of the Lr 20 or Lr 28 alleles for resistance.
57 citations
55 citations
TL;DR: A first attempt to build a dynamic simulation model of groundnut rust was reported, and simulated outputs were found fairly similar to observed rust severity and crop growth data from Adiopodoume, southern Ivory Coast.
34 citations
31 citations
TL;DR: The logistic model adequately explained the development of leaf rust in time and space and yield reductions in all the cultivars were significantly related to areas under the disease progress curve and distance from focus.
Abstract: (...) The average apparent infection rates of the epidemics were significantly different for different dates of inoculation. (...) Leaf rust severity was highly correlated with cumulative degree days following inoculation. (...) The logistic model adequately explained the development of leaf rust in time and space. Cultivar resistance affected leaf rust severity and extent of spread. (...) Yield reductions in all the cultivars were significantly related to areas under the disease progress curve and distance from focus. The significance of distance of spread in estimating yield reduction is discussed
29 citations
TL;DR: The mechanisms by which the effects of rust on host competitiveness differed under high and low nutrient conditions are considered and the implications for the understanding of the role of rusts in natural vegetation are discussed.
Abstract: Senecio vulgaris L., either healthy or inoculated with rust (Puccinia lagenophorae Cooke), was grown in monoculture or in mixture with Capsella bursa-pastoris (L.) Medic, under high or low nutrient conditions. At harvests made 7, 9, and 11 weeks after sowing, uninfected S. vulgaris progressively outcompeted C. bursa-pastoris under nutrient-rich conditions. Rust infection eliminated the competitive advantage of S. vulgaris over C. bursa-pastoris under high nutrient conditions. In contrast, under low nutrient conditions C. bursa-pastoris outcompeted uninfected S. vulgaris and infection with P. lagenophorae resulted in no additional competitive disadvantage to its host. The reduced competitiveness of rusted S. vulgaris under high nutrient conditions was associated with reductions in root growth in mixtures that were greater than those caused by rust in monocultures. The effects of nutrient supply, rust infection and competition on tissue concentrations of nitrogen, phosphorus and potassium were complex and often influenced by interactions between these factors. Increasing the nutrient supply increased nitrogen concentrations ([N]) in S. vulgaris, as did rust infection, but the effects of infection were confined to monocultures. In general [N] in C. bursa-pastoris showed rather less variation. Phosphorus concentrations ([P]) in C. bursa-pastoris increased with nutrient supply but under nutrient-rich conditions were reduced by competition. In S. vulgaris [P] increased with increasing nutrient supply and with infection but in both cases responses were confined to monoculture. Potassium concentration ([K]) in S. vulgaris was increased by rust, especially in mixtures. In C. bursa-pastoris [K] under high nutrient levels was higher in mixtures than in monoculture. The mechanisms by which the effects of rust on host competitiveness differed under high and low nutrient conditions are considered and the implications for our understanding of the role of rusts in natural vegetation are discussed.
28 citations
Journal Article•
27 citations
Journal Article•
25 citations
24 citations
TL;DR: It is concluded that rust infection of a sward may lead to changes in population structure with long-term yield effects, in addition to the immediate direct yield reductions commonly reported.
Abstract: Populations of Aberystwyth S23 and S24 ryegrass tillers were individually labelled and harvested at intervals to follow their life histories and productivity in response to the effect of infection with crown rust at two levels of nitrogen fertilization.
The number of tillers in a population was reduced as a result of infection with crown rust. Increased rates of tiller death due to the pathogen occurred throughout the population age-range and were most pronounced in the youngest tillers. Population changes were evident following infection and continued to be apparent in the following spring. The disease caused alterations in sward age structure, leading both to a higher proportion of older tillers in the more rust-damaged treatments and to a decrease in the weight of the herbage produced. It is concluded that rust infection of a sward may lead to changes in population structure with long-term yield effects, in addition to the immediate direct yield reductions commonly reported. The significance of these results to the ecological and agronomic balance of grassland is discussed.
TL;DR: Although rust severities are negatively correlated with soil pH at each and across all locations, rust severity is site- and cultivar-specific, and high levels of soil phosphorus were also associated with high rust severity at all locations.
Abstract: Sugarcane production in Florida has been affected by sugarcane rust, caused by Puccinia melanocephala, since the first recorded outbreak of the disease in 1979.(.)Although rust severities are negatively correlated with soil pH at each and across all locations, rust severity is site- and cultivar-specific. High levels of soil phosphorus were also associated with high rust severity at all locations. At two locations, high levels of soil magnesium and potassium were associated with lower rust severity(.)
Patent•
25 Oct 1990TL;DR: In this paper, an integer of 1 to 3 is used as a rust preventive which can be homogeneously mixed with a fluorine-containing grease, where m is 2 to 200.
Abstract: wherein m is 2 to 200, and n is an integer of 1 to 3 is used as a rust preventive which can be homogeneously mixed with a fluorine-containing grease.
TL;DR: In inoculation experiments, there was a significant reduction in the extent of rust and late leafspot development on leaves inoculated with V. lecanii.
Abstract: V. lecanii parasitized rust (Puccinia arachidis), early (Cercospora arachidicola [Mycosphaerella arachidis]) and late leafspot (Phaeoisariopsis personata [M. berkeleyi]) pathogens of groundnut in the greenhouse at ICRISAT Center and in farmers' fields in the Indian States of Andhra Pradesh, Karnataka and Tamil Nadu. In inoculation experiments, there was a significant reduction in the extent of rust and late leafspot development on leaves inoculated with V. lecanii. Receptivity and percentage leaf area damage of rust and late leafspot were reduced when inoculated with V. lecanii. The potential use of V. lecanii in biological control of rust and leafspot diseases of groundnut is discussed.
TL;DR: Two new approaches are proposed for characterization and characterization of the mechanisms behind Leaf rust resistance in triticale cultivars by exploiting the “spatially cryptic” nature of the SrSatu gene.
Abstract: Leaf rust resistance in five triticale cultivars was controlled by a single gene designated LrSatu. This gene was closely linked in coupling with the stem rust resistance gene SrSatu believed to be...
TL;DR: In this article, the presence of ascorbic acid (⩾0.05 M) in corroding media (brackish water) influences the formation of the usual corrosion species like β, γ -FeOOH and ferrihydrite, and retards the rate of rust formation.
TL;DR: Evaluation of milling and baking quality characteristics revealed that compared to ‘Thatcher’, RL6058 had a higher flour protein content, but that its milling, dough development and baking properties were inferior.
Abstract: The protection provided by the leaf rust resistance gene Lr34 against Puccinia recondita f. sp. tritici was studied in the field over two seasons. In leaf-rust inoculated and fungicide-sprayed control plots, yield of RL6058, the ‘Thatcher’ backcross line with Lr34, was compared to that of the susceptible cultivar ‘Thatcher’. Leaf rust severity remained low on RL6058 in both seasons, but was high on ‘Thatcher’. The latent period of wheat leaf rust isolate 3SA132 in flag leaves of RL6058 was 256 h longer than in ‘Thatcher’. The uredinium density on ‘Thatcher’ was 14.4/cm2, compared to 3.7/cm2 flag leaf surface on RL6058. Leaf rust infection of ‘Thatcher’ reduced the total grain yield per plot by 25.4% and 1,000 kernel mass by 15.6%. Leaf rust caused little or no damage on RL6058 and rusted plots outyielded the control plots by 0.3 %. Seed weight of RL6058 was reduced by 0.7%. Compared to previous greenhouse studies, the adult-plant resistance conferred by Lr34 is more clearly expressed in the field. Evaluation of milling and baking quality characteristics revealed that compared to ‘Thatcher’, RL6058 had a higher flour protein content, but that its milling, dough development and baking properties were inferior.
TL;DR: In this article, the authors showed that postponement of selection for rust resistance resulted in the loss of useful genes, and that mean rust resistance decreased from cycle 0 to cycle 10.
Abstract: (...) During the 10 cycles of selection, rust was found on the population each year but always at a low level. If resistance was selectively neutral in the absence of disease, recurrent selection would not have changed the level of resistance. However, mean rust resistance decreased from cycle 0 to cycle 10. This suggests that postponement of selection for rust resistance resulted in the loss of useful genes
Journal Article•
TL;DR: It was concluded that the presence of dsRNAs had no obvious effect on pathogen virulence or on growth rate as measured by rate of accumulation of leaf chitin or time to pustule eruption.
Abstract: Double-stranded (ds) RNAs were found to be present in 33 of 38 collections of rust fungi, representing 15 species from four genera. This finding suggests that dsRNAs occur commonly in rust fungi. Tests were undertaken to determine the role or phenotype associated with the presence of dsRNAs. Comparisons were made between strains of Puccinia sorghi (maize rust) that had different dsRNAs and two fully isogenic strains of Melampsora lini (flax rust), one with no dsRNA and one with at least 13 dsRNAs. It was concluded that dsRNAs had no obvious effect on pathogen virulence or on growth rate as measured by rate of accumulation of leaf chitin or time to pustule eruption. Also it was demonstrated that the presence of dsRNAs had no effect on the interaction that exists between rusts over short distances in the leaf. Key words: dsRNA, rust, function, incidence.
TL;DR: Maximum inhibition of in vitro germination of urediniospores and significant reduction in in vivo development of rust was exhibited by V. lecanii and P. islandicum and their culture filtrates.
Abstract: The effects of the mycoparasites, Acremonium persicinum, Eudarluca caricls, Penicillium islandicum. Tuberculina costaricana and Verticillium lecanii and their culture filtrates on in vitro germination and in vivo development of Puccinia arachidis were studied under laboratory and field conditions. All the mycoparasites and their culture filtrates inhibited urediniospore germination and reduced rust development by varying degrees. Maximum inhibition of in vitro germination of urediniospores and significant reduction in in vivo development of rust was exhibited by V. lecanii and P. islandicum and their culture filtrates. The inoculation of mycoparasites and rust on the same day gave better control of rust. Sprays of culture filtrates of V. lecanii and P. islandicum significantly reduced rust disease under field conditions.
TL;DR: In this paper, infrared adsorption spectroscopy was used for the characterization of iron oxides and oxyhydroxides formed in the early stages of the rusting process.
Abstract: Although much is known about the structure, composition, and growth dynamics of rust phases formed on constructional low alloy and weathering steels, several aspects remain controversial, particularly in coastal areas where water retention and chloride contents are high. The present study presents and discusses results from infrared adsorption spectroscopy, a differentiating technique for iron corrosion layers. Spectra were obtained from powdered inner and outer rust samples grown in simulated high chloride conditions under various relative humidify levels. These show potential for the characterisation of iron oxides and oxyhydroxides formed in the early stages of the rusting process, an essential step in the establishment of a general model of attack in chloride containing environments.
TL;DR: Investigations into the nature of this non-specific eliciting activity revealed that active molecules are periodate sensitive, negatively charged at neutral pH, and associated with a high molecular weight fraction.
Abstract: Intercellular washing fluids (IWF) were harvested from a range of wheat cultivars infected with either the leaf rust fungus (Puccinia recondite f.sp. tritici) or the stem rust fungus (Puccinia graminis f.sp. tritici). These fluids were then tested for their ability to elicit symptoms of chlorosis and necrosis in 14 wheat cultivars. Eliciting activity was found in all samples tested, irrespective of both the host cultivar infected by the rust fungus and the genotype of the infecting pathogen isolate. Healthy test cultivars either responded to all IWF preparations or were responsive to none of them. Investigations into the nature of this non-specific eliciting activity revealed that active molecules are periodate sensitive, negatively charged at neutral pH, and associated with a high molecular weight fraction.
Patent•
06 Aug 1990
TL;DR: In this article, the intensity of laser beams according to the properties of scale or rust to be removed by irradiation with the beams, smoothen the finished surface of a steel product and prevent a heat-affected zone from remaining in the base material by specifying the wavelength of the laser beams and pulse duration time.
Abstract: PURPOSE:To easily choose the intensity of laser beams according to the properties of scale or rust to be removed by irradiation with the beams, to smoothen the finished surface of a steel product and to prevent a heat-affected zone from remaining in the base material by specifying the wavelength of the laser beams and pulse duration time CONSTITUTION:Scale or rust sticking to an iron or steel material is irradiated with laser beams in a UV region such as excimer laser beams having 100-400nm wavelength for =100 times and the scale or rust can be removed by the expansive pressure, the purpose can be attained
TL;DR: Ten dry bean cultivars/lines with differential reactions to rust were used in growth chamber experiments to determine rust (Uromyces appendiculatus (Pers.) Unger var.
Abstract: Ten dry bean (Phaseolus vulgaris L.) cultivars/lines with differential reactions to rust were used in growth chamber experiments to determine rust (Uromyces appendiculatus (Pers.) Unger var. appendiculutus, (U a)), and common bacterial blight Xanthomonas campestris pv. phaseoli (E.F. Sm.) Dews. (X c p)) reactions on leaves when coinoculated with both pathogens. The X c p-U a necrosis symptoms were very different from those caused by X c p alone. Depending on the level of host susceptibility to rust, the X c p reaction remained confined within the rust pustule or spread beyond the pustule area, causing a necrosis of the entire leaf. Prior infection of bean seedlings with bean common mosaic virus (BCMV), NY-15 strain, reduced rust pustule size, but did not affect the reaction to X c p. Screening with X c p and BCMV can be done at the same time during the early vegetative stage, but the interactions of U a with X c p and of BCMV with U a need to be considered in screening for resistance.
Patent•
Agip1
TL;DR: In this paper, an additive for fuels and lubricating oils with detergent, dispersant and anti-rust properties is described, consisting essentially of the product of condensing a mixture of alkenylsuccinic acids or anhydrides of formula (I) where m and n, mutually independently, represent 0 or a whole number between 1 and 10 and are such that their sum is 9 or 10.
Abstract: of EP0393769An additive for fuels and lubricating oils with detergent, dispersant and anti-rust properties is described, consisting essentially of the product of condensing a mixture of alkenylsuccinic acids or anhydrides of formula (I) where m and n, mutually independently, represent 0 or a whole number between 1 and 10 and are such that their sum is 9 or 10, and @R is @O or (-OH, -OH), with triethylenetetramine of formula (II) H2N-(CH2-CH2-NH)3-H (II)