Preparation of controlled-release formulations of 14C-labelled thiobencarb herbicide and study of their environmental behaviour

Controlled-release formulations of ¹⁴C-labelled thiobencarb herbicide were prepared in calcium alginate using kaolin as an inexpensive filler. The rates of release of the herbicide from these and from a commercial granular formulation were studied in static distilled water contained in open and closed vessels. The rate of release of the herbicide was much higher from the commercial formulation than from the controlled-release formulations. Increasing the proportion of kaolin to calcium alginate in controlled-release formulations reduced the rate of release of the herbicide. There was a significant loss of thiobencarb-related radioactivity from the water solution when the vessels containing the solutions were left uncovered and exposed to light. The loss of the herbicide seemed to be due to degradation and evaporation.     

Foliar Application of Glycinebetaine and Salicylic Acid Improves Growth,Yield and Water Productivity of Hybrid Sunflower Planted by Different Sowing Methods

Improved planting methods and foliar application of glycinebetaine (GB) and salicylic acid (SA) can improve the water productivity in field crops under limited water supply conditions. A 2‐year field study was conducted to evaluate the possible role of different planting methods and foliar applications of GB and SA in improving the yield, quality and water productivity of hybrid sunflower (Helianthus annuus L.). The crop was planted by flat sowing (75 cm spaced rows) and ridge sowing (75 cm spaced ridges), with GB and SA applied exogenously at 100 and 0.724 mm , respectively, at both budding and flowering stages, while control plots received distilled water. Ridge sowing, rather than flat sowing, improved the biological yield, oil yield, leaf area index (LAI), crop growth rate (CGR), plant height, water‐use efficiency and final achene yield during both the years. Foliar applications of GB and SA at both the stages improved the achene yield, although foliar application of GB at flowering was the most effective. Neither the planting methods nor the foliar application of GB and SA altered the achene oil contents during both the years. Foliar application of GB and SA increased the free proline content of the leaf and GB contents at flowering but reduced the achene protein contents, whereas planting method had no effect on these attributes across the years. Of the foliar applied chemicals, GB was more effective in improving sunflower growth and yield and water productivity than SA. To conclude, ridge sowing coupled with foliar application of GB at flowering stage could be beneficial for achieving maximum yields of hybrid sunflower under relatively water limited conditions in the field.     

Glycinebetaine Improves Chilling Tolerance in Hybrid Maize

Plant growth and development is hampered by various environmental stresses including chilling. We investigated the possibility of improving chilling tolerance in hybrid maize by glycinebetaine (GB) seed treatments. Maize hybrid (Hycorn 8288) seeds were soaked in 50, 100 and 150 mg l^?1 (p.p.m.) aerated solution of GB for 24 h and were dried back. Treated and untreated seeds were sown at 27 °C (optimal temperature) and at 15 °C (chilling stress) under controlled conditions. Germination and seedling growth was significantly hindered under chilling stress. Moreover, chilling stress significantly reduced the starch metabolism and relative water contents (RWC), and increased the membrane electrolyte leakage. However, activities of antioxidants (catalase, superoxide dismutase and ascorbate peroxidase) were increased under stress conditions. Seed treatments with GB improved the germination rate, root and shoot length, seedling fresh and dry weights, leaf and root scores, RWC, soluble sugars, α‐amylase activity and antioxidants significantly compared with untreated seeds under optimal and stress conditions. Induction of chilling tolerance was attributed to maintenance of high tissue water contents, reduced membrane electrolyte leakage, and higher antioxidant activities and carbohydrate metabolism. Seed treatment with 100 mg l^?1 GB was the best treatment for improving the performance of hybrid maize under normal and stress conditions compared with control and other levels used.     

Postcranial Osteology of the most Primitive Artiodactyl: Diacodexis pakistanensis (Dichobunidae)

Diacodexis pakistanensis is the smallest and most primitive artiodactyl. It is known from the early Eocene of the Indo-Pakistani subcontinent. It retains a clavicle, has five complete digits in the manus and four in the pes and is digitigrade. The elongated limbs, reduced ability to pronate and supinate, double pulleyed astragalus and reduced lateral digits indicate that D. pakistanensis is cursorial. However, the shape of the spinous processes of the sacrum, the size of the deltoid tubercle of the humerus, the shape of the proximal femur, the narrow distal trochlea of the astragalus and proportions of the long bones indicate that it is less cursorial than any other dichobunid artiodactyl.     

Antinociceptive diterpene from Euphorbia decipiens

One myrsinol-type diterpene ester (1) isolated from Euphorbia decipiens was evaluated for analgesic activity in the acetic acid induced writhing test in mice. Different dose (5-20 mg/kg i.p.) of the compound showed significant antinociceptive activity, which was comparable to standard analgesic drugs, aspirin and ibuprofen (100 mg/kg i.p.).     

Cardiovascular Responses to Glibenclamide During Endotoxaemia in the Pig

Vanelli, G., Hussain, S.N.A., Dimori, M. and Aguggini, G., 1996. Cardiovascular responses to glibenclamide during endotoxaemia in the pig. Veterinary Research Communications, 21(3), 187-200The effects of blockading the ATP-sensitive potassium channel (K+ATP channels) on endotoxin-induced vascular derangements was studied. Escherichia coli endotoxin was infused (20 µg/kg per h) intravenously for 180 min into anaesthetized, mechanically ventilated, indomethacin-treated pigs. After 150 min of endotoxaemia, glibenclamide (a K+ATP channel blocker) was infused intravenously at 2 mg/kg per min for 5 min. The cardiovascular parameters were recorded before (control), every 30 min up to 150 min during endotoxaemia, and then at 5, 15 and 30 min after administration of glibenclamide. Infusion of endotoxin reduced the systemic arterial pressure to 60.6% ± 3.7% (p < 0.01) and increased the pulmonary arterial pressure by 75.9% ± 11.0% (p < 0.01) of the control values. Within 5 min, infusion of glibenclamide transiently but significantly reversed the systemic hypotension by raising the systemic vascular resistance, whereas the increased pulmonary arterial pressure was further augmented. Glibenclamide infusion did not influence the cardiac output. Within 30 min, the cardiovascular parameters had returned to the values induced by endotoxin, except for the systemic vascular resistance. Infusion of glibenclamide into normal pigs did not change the systemic pressure or resistance, but the pulmonary pressure and resistance were augmented transiently. These data suggest that, in pigs, the ATP-sensitive K+ channels may be one factor playing a role in the vascular changes due to endotoxaemia, especially in the systemic circulation.     

Effects of Time and Rate of Nitrogen and Phosphorus Application on the Growth and the Seed and Oil Yields of Canola (Brassica napus L.)

A field study was conducted to investigate the influence of variable rates of application of N and P fertilizers in splits at various times on the growth and the seed and oil yields of canola (Brassica napus L.) during 1995–97. Rates of fertilizer application were 0 and 0 (F0), 60 and 0 (F1), 0 and 30 (F2), 60 and 30 (F3), 90 and 60 (F4) and 120 and 90 (F5) kg N ha^?1 and kg P₂O₅ ha^?1. All the P was applied at sowing while N was applied in splits, i.e. all at sowing, half at sowing and half with first irrigation, or half at sowing and half at flowering. The responses of growth, seed yield and components of yield were consistent in both years. Increasing the rate of fertilizer application from F4 (90/60 kg N/P₂O₅ ha^?1) to F5 (120/90 kg N/P₂O₅ ha^?1) increased the leaf area index (LAI) relative to the control and to lower rates of fertilizer application. For both crops, application of 90/60 kg N/P₂O₅ ha^?1 significantly enhanced total dry matter (TDM) and seed yield. Seed yield increased mainly due to a greater number of pods per plant and seeds per seed‐pod. The time of fertilizer application did not significantly affect seed yield or components of yield in either season. Oil yield generally followed seed yield, increasing with increasing rate of fertilizer application up to 90/60 kg N/P₂O₅ ha^?1. The maximum oil contents were obtained from the control. The results show that seed and oil yields of canola were maximized at the F4 (90/60 kg N/P₂O₅ ha^?1) rate of application under the agro‐ecological conditions of Faisalabad, Pakistan.     

Identification of cultivars of pasture legumes (Centrosema macrocarpum,C. pubescens and C. sp.n.) by acid polyacrylamide gel electrophoresis of cotyledons storage proteins

Summary An electrophoretic procedure was developed for storage proteins which can discriminate cultivars of forage legumes, Centrosema macrocarpum, C. pubescens and C. sp.n. Proteins extracted from cotyledons were separated in 10% polyacrylamide gel containing 10% sucrose. Electrophoretic patterns are presented to illustrate the results that can be obtained with the procedure described. Cultivars of all three species were distinguishable based upon the variation in their acid soluble seed proteins.Joint publiccation of the Department of Food Science, University of Manitoba (No 101) and Centro Internacional de Agricultura Tropical-CIAT.