Influence of salinity in irrigation water on forage sorghum and soil chemical properties

Abstract

Soluble salts found in wastewater can be toxic when used for irrigation of forages. Thus, two greenhouse experiments were conducted to investigate effects of saline [CaCl₂NaCl (3:1, w:w)] treatments on soil chemical properties and ‘Dekalb FS‐5’ forage sorghum [Sorghum bicolor(L.) Moench]. Treatments for the first experiment consisted of a nonsaline control or 500 mL of a solution with an electrical conductivity (EC) of 10 dS m^?1 applied once. In the second experiment, treatments were salinity levels of 1.7,3.5,5.2,8.5, and 12.2 dS m^?1, applied in non‐nitrogenous Hoagland's solution as the sole source of irrigation. Both experiments were replicated four times. For both experiments forage sorghum was seeded in pots containing 7 kg of air‐dried Amarillo fine sandy loam soil. Sorghum survivability and plant height were measured. In the second experiment, water use by sorghum was also measured. Plants were harvested 7 wk after seeding, weighed, dried at 55°C, weighed, and ground for subsequent mineral analysis. After harvest, soil salinity, pH, and in the second experiment, extractable soil elements were determined. Soil salinity increased, while soil pH decreased, with the salinity treatments. Extracted soil calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), manganese (Mn), and cadmium (Cd) increased while sulfur (S), iron (Fe), and copper (Cu) decreased, and aluminum (Al) and zinc (Zn) exhibited no change with increasing salinity. Sorghum aerial plant and root production decreased with increasing salinity. Plant Ca, strontium (Sr), Mn, and Cd levels increased with increasing salinity. In contrast, sorghum K, P, and S levels declined with increasing salinity.     

Soil Ca, Al, acidity and penetration resistance with subsoiling, lime and gypsum treatments

Abstract. Crop growth on strongly weathered soils is often limited by soil compaction in addition to aluminium toxicity and/or calcium deficiency. This study examines the effects of subsoiling, lime and gypsum on penetrometer resistance, acidity, aluminium and calcium levels and cotton ( Gossypium hirsutum L.) root growth on soils transitional between Cecil and Appling series (clayey, kaolinitic, thermic Typic Hapludults) in the Piedmont region of Georgia, USA. The main plots were subsoiled to depths of 0.35 or 0.80 m or untreated. Dolomitic limestone (0 or 4.03 t per hectare on subplots) and phosphogypsum (0 or 10 t per hectare on sub-subplots) were incorporated into the surface soil (0.15 m). Deep subsoiling (0.80 m depth) decreased penetrometer resistance at 0.3–0.5 m depth and increased yield in two of three years, but there was no response to shallow subsoiling (0.35 m depth). Lime increased yield when surface soil water pH prior to amendment was less than a Cate-Nelson critical value of 4.6. Gypsum moved downward much more rapidly than lime, increasing soil solution calcium ion activity to a depth of 0.8 m within 5 months of application. There were differences in clay content between replicate plots and calcium movement was faster where the clay content was less. Yield responses to gypsum in 1986 were attributed to increased root growth below 0.2 m resulting from the increased calcium ion activity. Yield response to gypsum in limed sub-subplots was significant only in 1986.     

Chemical comparison of goldenseal (Hydrastis canadensis L.) root powder from three commercial suppliers

The characterization of herbal materials is a significant challenge to analytical chemists. Goldenseal (Hydrastis canadensis L.), which has been chosen for toxicity evaluation by NIEHS, is among the top 15 herbal supplements currently on the market and contains a complex mixture of indigenous components ranging from carbohydrates and amino acids to isoquinoline alkaloids. One key component of herbal supplement production is botanical authentication, which is also recommended prior to initiation of efficacy or toxicological studies. To evaluate material available to consumers, goldenseal root powder was obtained from three commercial suppliers and a strategy was developed for characterization and comparison that included Soxhlet extraction, HPLC, GC-MS, and LC-MS analyses. HPLC was used to determine the weight percentages of the goldenseal alkaloids berberine, hydrastine, and canadine in the various extract residues. Palmatine, an isoquinoline alkaloid native to Coptis spp. and other common goldenseal adulterants, was also quantitated using HPLC. GC-MS was used to identify non-alkaloid constituents in goldenseal root powder, whereas LC-MS was used to identify alkaloid components. After review of the characterization data, it was determined that alkaloid content was the best biomarker for goldenseal. A 20-min ambient extraction method for the determination of alkaloid content was also developed and used to analyze the commercial material. All three lots of purchased material contained goldenseal alkaloids hydrastinine, berberastine, tetrahydroberberastine, canadaline, berberine, hydrastine, and canadine. Material from a single supplier also contained palmatine, coptisine, and jatrorrhizine, thus indicating that the material was not pure goldenseal. Comparative data for three commercial sources of goldenseal root powder are presented.     

Genital pathology of feral male goats

Genitalia from 1000 feral male goats derived from western Queensland and New South Wales were examined after slaughter at an abattoir and the prevalence of abnormalities determined. Ulcerative balanoposthitis, considered due to caprine herpesvirus infection, was observed in 11 animals (1.1%); acidophilic intranuclear inclusions were found in 7 of these. Other conditions included focal hypoplasia of seminiferous tubules in 2 bucks (0.2%), segmental aplasia of the epididymis (one buck, 0.1%), bulbourethral gland cysts with contained aggregations (33 bucks, 3.3%) and haemangiosarcoma of the bulbourethral gland in one animal. The low prevalence of several conditions such as spermatic granuloma, cryptorchidism, and testicular hypoplasia, was attributed largely to the fact that the bucks examined were horned so that the recognised association between genital abnormalities and polledness did not apply.     

Immunohistochemical detection of canine distemper virus in haired skin, nasal mucosa, and footpad epithelium: a method for antemortem diagnosis of infection.

A reliable antemortem diagnostic method is needed for determining infection with canine distemper virus (CDV). The utility of immunohistochemical detection of CDV antigen was examined was examined for samples of nasal and footpad epithelium and haired skin in dogs with and without detectable CDV antigen in the lung and/or brain. Tissues from 57 dogs at risk of CDV infection were tested. Viral antigen was found in the lung and/or brain of 28 dogs. Among these dogs, viral antigen was demonstrated in the epithelial cells of the nasal mucosa in 24 of 27 dogs, in the footpad epithelium in 24 of 26 dogs, and in the haired skin of the dorsal neck in 26 of 27 dogs. Among the 29 dogs without CDV antigen in either the lung or brain, 1 dog had positive staining for viral antigen in the skin and nasal mucosa. Biopsies of haired skin of the dorsal neck, which is relatively simple to sample, can be used for immunohistochemical testing for acute and subacute infection with CDV.     

Tick paralysis in dogs and cats in Australia: treatment and prevention deliverables from 100 years of research

This review of tick paralysis caused by Ixodes holocyclus in Australia addresses the question: What are the key discoveries that have enabled effective treatment and prevention of tick paralysis in dogs and cats? Critical examination of 100 years of literature reveals that arguably only three achievements have advanced treatment and prevention of tick paralysis in animals. First, the most significant treatment advance was the commercial availability of tick antiserum in the 1930s. Hyperimmune serum currently remains the only specific anti-paralysis tick therapy available to veterinarians in Australia. Second, advances in veterinary critical care have increased survival rates of the most severely affected dogs and cats. Critical care advancements have been enabled through specialised veterinary hospitals that can provide appropriate care 24 h a day, and advanced training of veterinarians, veterinary nurses and technicians. Third, perhaps that biggest advance of all in the last 100 years of research has been the commercial availability of the isooxazoline class of acaricidal preventatives in Australia specifically for I. holocyclus. This highly effective class of preventatives offers long duration of action, low cost, spot-on or oral formulations and a low rate of adverse reactions. Animal owners and veterinarians now have the most useful tool of all – a reliable preventative. This review reveals the key events in research over the last 100 years and the tortuous pathway to delivering better treatment and preventative options for this enigmatic Australian parasite.     

A retrospective study of non-suppurative encephalitis in beef cattle from western Canada

Non-suppurative encephalitis occurs sporadically in beef cattle in western Canada, leading to loss of animals. This retrospective study investigated the presence of viral, bacterial, and protozoal antigens or DNA in 37 western Canadian feedlot cattle with non-suppurative encephalitis for which a cause had not been identified. Cases were selected based on the age of the animal (> 7 months), and clinical history of recumbency and depression. The identification of rabies in 1 case stresses the importance of including this viral disease in the list of differential diagnoses. Because there was variation in the severity, distribution, and type of lesions, it is possible that there may be more than 1 cause, but failure to identify an infectious agent might also suggest that non-infectious agents could play a role.     

The lipid compositions of two isolates of Cladosporium cucumerinum do not explain their differences in sensitivity to fungicides which inhibit sterol biosynthesis

Isolate 840905 of Cladosporium cucumerinum, when grown on agar or in liqiud medium, was sensitive to triadimenol, HWG 1608 (tebuconazole), fenpropimorph and pimaricin but relatively resistant to terbinafine. Conversely, isolate 49628 was sensitive to terbinafine but relatively resistant to the other fungicides. Changes in sterol composition following treatment with the fungicides reflected the known modes of action of each fungicide. When individual enantiomers of triadimenol were tested against isolate 840905 the order of activity in reducing mycelial growth was 1 S, 2R > 1R, 2R > 1R, 2S ≈? 1S, 2S, and this was paralleled by the depletion of ergosterol and the appearance of 14α-methyl sterols. Isolate 49628 had a greater saturated:unsaturated fatty acid ratio than did isolate 840905 but no major changes in fatty acid composition of either isolate were induced by fungicide treatment. There appears to be no obvious explanation for the differences in fungicide sensitivity of the isolates in terms of their lipid compositions.     

Temporal,environmental and management factors influencing the epidemiological patterns of sea lice (Lepeophtheirus salmonis) infestations on farmed Atlantic salmon (Salmo salar) in Scotland

In association with industry, an extensive database has been established on measurements of sea louse counts on farmed Atlantic salmon for the years 1996 to 2000 from 33 Scottish fish farms. These data include extensive counts on the sea louse species, Lepeophtheirus salmonis, at various stages of the life cycle and in particular the chalimus and mobile stages. There has been considerable speculation as to what factors might affect the abundance of sea lice, much of which is based on limited evidence. Our analyses show that there is tremendous variation in sea louse infestation patterns from year to year, whereas stock type, geographical region and coastal exposure do not appear to affect mean levels of abundance. In contrast, treatments lead to pronounced cycles of sea louse infestation with peaks and troughs at 3-week intervals, and these interventions are important if the sea louse levels on fish are to be controlled. There was no evidence of water temperature affecting the mean annual abundance of sea louse infestation.