SOME WEED SPECIES AFFECTING SOYBEAN NODULATION AND NODULE FUNCTION

Experiments aimed at examining the effect of aqueous extracts of three weed species on nodulation and nodule function of soybean cv. Melrose have been carried out at the Laboratory of Plant Physiology and Biotechnology, Department of Agronomy and Soil Science, University of New England, Australia. Aqueous extracts of fresh weed material (Amaranthus powellii, Cyperus rotundus and Paspalum dilatatum) at the concentration of 10% (w/v) were added to a minus-nitrogen Hoagland’s nutrient solution in which the soybean plants were grown with 14 hours day length, day and night temperatures of 28 and 20°C, respectively, light intensity of 790 mol/m2/s, and the relative humidity of 65%. The plants were kept for three weeks prior to the measurement of activity of nitrogenase enzyme and ammonium content of the root nodules. All weed extracts tested resulted in impairment of soybean nodulation and nodule function as indicated by reduced activity of nitrogenase enzyme activity (acetylene reduction assay - ARA). Although amaranth extract was most inhibitory to the nitrogenase enzyme activity, it was less inhibitory than nutgrass extract in reducing the total ammonium content of the soybean root nodules

Some Weed Species Affecting Soybean Nodulation And Nodule Function

Experiments aimed at examining the effect of aqueous extracts of three weed species on nodulation and nodule function of soybean cv. Melrose have been carried out at the Laboratory of Plant Physiology and Biotechnology, Department of Agronomy and Soil Science, University of New England, Australia. Aqueous extracts of fresh weed material (Amaranthus powellii, Cyperus rotundus and Paspalum dilatatum) at the concentration of 10% (w/v) were added to a minus-nitrogen Hoagland\u27s nutrient solution in which the soybean plants were grown with 14 hours day length, day and night temperatures of 28 and 20°C, respectively, light intensity of 790 mmol/m2/s, and the relative humidity of 65%. The plants were kept for three weeks prior to the measurement of activity of nitrogenase enzyme and ammonium content of the root nodules. Results demonstrate that all weed extracts reduced the nodulation and nitrogenase activities (ARA) of soybean cv. Melrose. Amaranth was most inhibitory to nitrogenase enzyme activity. However, amaranth extract was less inhibitory than nutgrass extract in total ammonium content

Phosphorus and Manganese Seed Coatings for Crop Growth and Yield

This thesis investigates seed coating as a method of improving the efficiency of fertiliser applications for phosphorus (P) and manganese (Mn) to crop species. Seed coating provides a great opportunity of placing precise amounts of nutrient in close proximity to the seed to enable immediate access to nutrients. However, this close contact of seed and fertiliser can be detrimental and both delay and reduce emergence. This is not a limitation to coating seeds with Mn it can however be a serious problem with P seed coating

Strategies for Growing Canola in Low Rainfall Environments of Australia

Canola ('Brassica napus') production in Australia, although generally successful, is not well developed in the low rainfall environments of the eastern wheat belt. Whilst there are varieties being developed to allow increased canola production in these areas, there is limited understanding of the relationship between sowing time, variety, soil moisture and plant growth. The experiments detailed in this thesis set out to examine these issues and provide an understanding of which of these factors, or a combination of these, limit canola production in low rainfall environments. Two field experiments were conducted comparing plant growth, yield and yield components and water use of several canola varieties sown across a series of sowing times, under two water regimes, one involving the application of supplementary water using irrigation. These were conducted during 2002 and 2003 at Condobolin in the central western district of New South Wales. ... The results from this study illustrate that early sowing of canola in low rainfall environments of Australia could increase canola production and that correct varietal choice might further increase grain yields. However, caution must be extended when considering how much earlier canola should be sown than the current recommendations, as there may be other factors which could alter plant growth and yield that were unable to be investigated in this thesis

Factors affecting the sensitivity of chickpea ('Cicer arietinum') to isoxaflutole and its effect on nitrogen fixation

One of the major obstacles in growing chickpea ('Cicer arietinum) successfully is its poor ability to compete with weeds. Heavy crop losses are possible in weedy situations and the lack of registered post-emergence herbicides for broadleaf weeds reduces the options for weed management. In Australia, isoxaflutole at 75 g a.i. ha⁻¹ is registered for the control of several difficult-to-control broadleaf weeds [e.g. Indian hedge mustard ('Sisymbrium orientale'), sowthistle ('Sonchus oleraceus'), capeweed ('Arctotheca calendula'), prickly lettuce ('Lactuca serriola'), wild radish ('Raphanus raphanistrum'), turnip weed ('Rapistrum rugosum'), crassula ('Crasulla' spp.), medic ('Medicago' spp.), deadnettle ('Lamium amplexicaule'), and slender celery ('Ciclospermum leptophyllum')] in chickpea. However, there have been records of chickpea crop damage due to the application of isoxaflutole at the recommended rate. The main objectives of this study were to identify genotypes tolerant or sensitive to this herbicide, to determine the soil and environmental factors affecting the herbicide sensitivity of the genotypes and to examine the effect this herbicide has on nodulation and nitrogen fixation. Variety screening trials with a range of isoxaflutole rates have found that the chickpea genotypes Howzat, Yorker, 91025-3021 (desi types), FLIP 94-92C and S 95425 (kabuli tyopes) were more susceptible to isoxaflutole damage. In comparison, the desi genotypes 97039-1275 and Kyabra recorded very minor injury and can be regarded as the most tolerant. Other genotypes - Gully, Jimbour, Amethyst, Flipper, ICLL 87322 (desi types) and Bumper, FLIP 94-90C, GCN 133-2, IG 9337, IG 96220, Kaniva, Macarena, S 95342 (kabuli types) - are intermediate in their response to isoxaflutole

Understory Cover Responses to Piñon-Juniper Treatments Across Tree Dominance Gradients in the Great Basin

Piñon (Pinus spp.) and juniper (Juniperus spp.) trees are reduced to restore native vegetation and avoid severe fires where they have expanded into sagebrush (Artemisia tridentata Nutt.) communities. However, what phase of tree infilling should treatments target to retain desirable understory cover and avoid weed dominance? Prescribed fire and tree felling were applied to 8–20-ha treatment plots at 11 sites across the Great Basin with a tree-shredding treatment also applied to four Utah sites. Treatments were applied across a tree infilling gradient as quantified by a covariate tree dominance index (TDI=tree cover/[tree+shrub+tall perennial grass cover]). Mixed model analysis of covariance indicated that treatment x covariate interactions were significant (P 0.4). Fire increased cheatgrass (Bromus tectorum L.) cover by an average of 4.2% for all values of TDI. Cutting or shredding trees generally produced similar responses and increased total perennial herbaceous and cheatgrass cover by an average of 10.2% and 3.8%, at TDIs ≥ 0.35 and ≥ 0.45. Cheatgrass cover estimated across the region was < 6% after treatment, but two warmer sites had high cheatgrass cover before (19.2% and 27.2%) and after tree reduction (26.6% and 50.4%). Fuel control treatments are viable management options for increasing understory cover across a range of sites and tree cover gradients, but should be accompanied by revegetation on warmer sites with depleted understories where cheatgrass is highly adapted. Shrub and perennial herbaceous cover can be maintained by mechanically treating at lower TDI. Perennial herbaceous cover is key for avoiding biotic and abiotic thresholds in this system through resisting weed dominance and erosion.Keywords: brush control, state and transition, prescribed fire, resilience, thresholds, mechanical treatments, masticatio

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass