Showing papers on "Rust published in 1976"

Crystal structure of green rust formed by corrosion of cast iron

Abstract: THE principal solid corrosion products of iron in water are magnetite and hydrated forms of ferric oxide, depending on the degree of oxidation. The occurrence of intermediate products, termed green rusts, was reported by Keller1 in 1948, since when the formation and decomposition of these compounds, precipitated from aqueous solution by controlled oxidation of ferrous hydroxide, have been extensively studied2–5. It has been proposed2,3 that specific anions are incorporated in the crystal structure of some green rusts, although no substantial evidence has been found to confirm this. A number of green rusts have been classified crystallographically3 as follows: first, rhombohedral green rusts I (GRI) formed in Cl−, SO42− and Br− solutions and (second), hexagonal green rust II (GRII) formed only in SO42− solutions by decomposition of GRI. The interrelationships between the various products involved in the oxidation of ferrous hydroxide have been summarised by Misawa et al.5 In this paper a preliminary account is given of the crystal structure of a rhombohedral green rust formed by corrosion of iron which, although of similar unit cell dimensions to GRI, differs structurally from those previously reported.

Effects of Fungicide Spraying on Brown Rust and Yield in Spring Barley

Abstract: SUMMARY In three field experiments in Cornwall in 1969–71, spraying 6–8 times with the fungicides zineb or oxycarboxin gave good control of severe attacks of brown rust (Puccinia hordei) in four cultivars of spring barley and increased the persistence of green leaf tissue. The disease developed late in the season, mainly after ear emergence, Other leaf diseases were slight, except for mildew (Erysiphe graminis) in 1971 in one cultivar. Spraying resulted in increases in grain yield ranging from 17 to 31 per cent and these were almost wholly due to increased grain weight (1000-grain weight). One and two-spray programmes of the fungicides gave only a partial control of brown rust and small yield increases. There was a statistically significant relationship between grain yield and brown rust recorded at growth stage 75 (11.1),* an increase of 10 per cent in brown rust on the second top leaf reducing yield by 7.7 per cent.

Mycoflora of rust-infected and non-infected plant material during decay

Abstract: Poplar leaves, plum leaves and wheat stems, bearing telia of Melampsora larici-populina Kleb., Tranzschelia pruni-spinosae (Pers.) Diet. var. discolor (Fuckel) Dunegan and Puccinia graminis Pers. f.sp. tritici Eriks. & Henn., respectively, supported a fungal succession quantitatively different from that on non-infected leaves and stems, during decay after leaf-fall or harvest. No colonizers were restricted to rust-infected or non-infected material but most were more common on one type or the other.

Observations on the epidemiology and effect on grain yield of brown rust in spring barley

Abstract: SUMMARY In observations made over four seasons, counts of brown rust spores trapped above barley crops and infections of healthy plants placed within crops, indicated that there was a high risk of infection on days when at least 5 far of dew were recorded following a day on which the maximum temperature was greater than 15°C. In spray-timing trials, the fungicidal sprays applied between the first appearance of brown rust in the crop and the beginning of the exponential phase of the epidemic usually were associated with the highest yields. The relationships between levels of brown rust and yields in these trials is discussed in connection with their relevance to the estimation of losses caused by the disease.

Resistance of soybean to rust in Australia

Abstract: Previously no immunity or high degree of resistance to soybean rust has been reported. The tests described have demonstrated that strong resistance to rust does exist in soybean genotypes, and in particular in one accession of P1200492 (Q12956) and the cultivars derived from it (Tainung 3 and Tainung 4) and in lines P1227268, PI227687 and HY2217. However, these resistances may not be effective against the whole rust population, as evidenced by the identification of a second race of rust which is virulent on the previously immune line P1200492. Rust of soybeans, caused by Phakopsora pachyrhizi Syd., is reported to be widely distributed throughout Asia from China south to Australia (1, 6, 10). The rust causes premature defoliation of plants, with a subsequent increase in the numbers of unfilled pods per plant. Disease loss has not been accurately determined, but the data available show that this disease can cause serious yield loss. In Taiwan it is estimated that, due to rust, production is reduced by 20-30% (8), whilst in individual fields as much as 70-80% of potential yield may be lost (4). In Japan, losses of 15-40% in individual fields are reported (7), and in Thailand losses are estimated to range from 10-30% in individual fields (8). No accurate measures of yield loss have been reported for Australian crops. Screening tests of soybean accessions have been carried out in several countries where the rust is indigenous, to identify sources of resistance to rust. The tests have shown that accessions differ in the severity of rust development that occurs on them, and show varying amounts of field resistance. However, no soybean lines which are immune to the rust, or which show a high degree of resistance have been reported (1). Accession P1200492 (a) was shown to have a high degree of field resistance to rust when tested in Taiwan (2, 3), though it was infected and sporulation occurred readily in glasshouse tests made in the U.S.A. using a Taiwanese isolate (9). PI200492 was used subsequently as a parent to breed cultivars Tainung 3 and Tainung 4 which showed degrees of rust resistance in Taiwan (2, 3)

Rust inhibitor and compositions thereof

Abstract: Novel dicarboxylic ester-acids resulting from the condensation of an alkenylsuccinic anhydride with an aliphatic hydroxy acid having from 2 to about 18 carbon atoms and amine salts of said ester-acid are useful as rust or corrosion inhibitors in organic compositions.

Rust-proof lubricant compositions

Abstract: Rust-proof lubricant compositions for coating metals comprising mono, di- or tri-partial esters synthesized from pentaerythritol and fatty acids having more than 6 carbon atoms including the corresponding isomers, or a mixutre thereof as chief constituents.

Germination of Puccinia striiformis uredospores on leaves of adult winter wheat plants

Abstract: SUMMARY In experiments with intact adult winter wheat plants and detached leaves, higher percentages of Puccinia striiformis uredospores germinated on the adaxial leaf surface, particularly the distal parts, than on the abaxial surface. This is consistent with the observation that the distal parts of the adaxial leaf surface are those which are most susceptible to yellow rust. Higher percentages of uredospores germinated on leaves of some of the winter wheat varieties examined than on those of others. These varietal differences depended on the part of leaf and the race of P. Striiformis used for the comparisons. This suggests that the differences between varieties are partly race specific.

White rust inhibitor

Abstract: A white rust inhibited composition is comprised of a zinc containing substrate. A white rust inhibiting composition contacts the substrate and is comprised of a vapor corrosion inhibitor and a pH adjusting compound to adjust and maintain the pH of the white rust inhibiting composition between 8 and 12.5.

Leaf Injury and Defoliation Caused by the Citrus Rust Mite, Phyllocoptruta Oleivora

Abstract: The persistence of high populations of citrus rust mite in untreated Valencia orange groves from late October 1974 to early January 1975 combined with abnormally dry weather caused severe injury to both the spring and summer flushes of leaves. Seventy percent of the leaves had one or more types of rust mite injury of varying severity. Upper surface injury occurred on 43.7% of the leaves and was most prevalent on spring flush. Lower surface injury and mesophyll collapse occurred on 37.4 and 19.0% of the leaves, respectively, and were most prevalent on summer flush. Overall defoliation of both healthy and injured leaves was 9.5% being significantly greater on summer flush. Citrus rust mite injury to the lower leaf surface appeared to be associated with defoliation. The area of injured leaf surface in relation to leaf size appeared to have no effect on leaf abscission. The interaction between the various types of leaf injury associated with citrus rust mite and prolonged moisture stress in relation to defoliation is discussed.

Rust preventing coating composition

Abstract: A rust preventive coating composition having a long pot life and providing a coating in which generation of white rust is greatly reduced, said coating composition being obtained by incorporating a small amount of at least one salt selected from the group consisting of molybdate salts, tungstate salts, phosphomolybdate salts and phosphotungstate salts into a coating composition comprising as main components an alkali metal silicate or ammonium silicate and zinc powder.

Rust proof pigment composition

Abstract: PURPOSE: Aluminum polyphosphate is mixed with one ore more compounds selected from borates and phosphates to provide a rost proof composition having reduced toxicity and good rust prevention. COPYRIGHT: (C)1978,JPO&Japio

Results from two barley experiments at Saxmundham, Suffolk, measuring effects of the fungicide benodanil on three varieties, given three amounts of nitrogen at two times 1973–4

Abstract: Midas, a barley variety very susceptible to brown rust (Puccinia hordei), and two less susceptible varieties (Julia and Mazurka) were given three amounts of nitrogen (50, 100 or 150 kgN/ha) either at sowing (in March), in May, or half at each time. Benodanil sprays were applied to one half of each plot in June and again in July to control brown rust. Brown rust became more severe in 1973 than in 1974 and was most severe on Midas with 150kgN/ha. In 1973, there was most brown rust where all or part of the nitrogen was applied in May, but in 1974 there was least brown rust where all the nitrogen was applied in May, probably because dry weather limited its uptake. In 1973, when ample rain fell in spring and summer, grain yield was increased more by nitrogen given in May than in March, especially when benodanil was given. In 1974, little rain fell until July and then March nitrogen increased grain yield most whether or not benodanil was given. Top dressing of N (in May) produced a smaller straw yield than seed-bed dressing did in each year. Benodanil spray much decreased brown rust and increased yield of grain, but not of straw; the increase was greater in 1973 than in 1974, when brown rust was less abundant. Benodanil increased yields of all varieties, but that of the rust susceptible variety, Midas, most. Benodanil increased grain yield more, as more N was given to the barley, and more with N given in May than in March. It increased the amount of N removed by the barley grain, but not by the straw.

Oillsoluble lubricant additives

Abstract: PURPOSE:Lubricating oil additives for dispersing insol. foreign matters mingled therein, for preventing harmful deposition in internal combustion engines, and for protecting them from corrosion or rust due to water or acidic substances produced during burning.

On the Cronartium stem rust(s) of five-needle pines in Japan.

Abstract: The sketchy history of occurrence of Cronartium stem rust of white pines in Japan and adjacent eastern Asia is reviewed. Current taxonomic problems with this group of rust are discussed and a more flexible taxonomic concept, with added consideration of physiological differences, is suggested. Some recent collections of the rust and artificial inoculations are reported.

Conimitella (Saxifragaceae) and its rust

Abstract: A rust found on Conimitella williamsii in southwest Alberta and central Colorado is referable to Puccinia saxifragae var. heucherarum. Morphology and the rust relationship suggest that Conimitella diverged from a moderately advanced Heuchera.

Multifunctional acrylates as foliar fungicides

Abstract: Multifunctional acrylates such as pentaerythritol triacrylate for protectant control of e.g., leaf rust of wheat, late blight of tomato rice blast disease and bean rust.

Group II metal mixed salts of two different organic acids in lubricant

Abstract: Group II metal mixed salts of: (A) an oil-soluble hydrocarbyl sulfonic acid; and (B) a polyoxyalkylenated sulfuric acid are useful as rust inhibitors in lubricating oil compositions.

Geographic Variation in Melampsora Rust Resistance in Eastern Cottonwood in the Lower Mississippi Valley

Abstract: -Eastern cottonwood clones originating from 36 young natural stands along the Mississippi River from Memphis, Tennessee, to Baton Rouge, Louisiana, were evaluated in a nursery near Greenville, Mississippi for resi~tance to Melampsora rust. In general, the northern sources had more rust and were more variable in rust susceptibility than the southern sources. Eleven percent of the clones from the 6 northernmost sources and 0.5 percent of the clones from the 24 southernmost sources appeared to be highly resistant to rust. Clones with slightly less rust resistance wer.e about evenly distributed over the geographic range. Additional keywords: Populus deltoides, Melampsora medusae.