844 resultados para Germination success


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Understanding how weed seed germination and emergence respond to environmental factors is critical to determining their adaptive capabilities and potential for infestations, and could also aid in the development of effective control practices. Germination of Ipomoea asarifolia (Desr.) Roem. & Schultz and Stachytarpheta cayennensis (Rich) Vahl. decreased linearly with decreasing osmotic potentials. Also, increasing osmotic stress delayed germination of Ipomoea more than that of Stachytarpheta. Ipomoea germination was insensitive to light, while Stachytarpheta showed a positive photoblastic behavior. Nitrate had a negative effect on germination of Ipomoea seed under both light and dark conditions but stimulated dark germination of Stachytarpheta. Ipomoea emergence was not significantly affected by planting depth. However, for Stachytarpheta emergence was restrited to seeds planted at the soil surface. Emergence of Ipomoea seedlings from greater than 6cm significantly decreased the amount of biomass allocated to roots, while biomass allocated to leaves was decreased for seedlings that emerged from depths greater than 2cm. These germination and emergence responses are discussed in relation to their ecological implications and to weed control strategies.

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ERP system is now attracting the SMEs, as it is now economical and affordable for them. The current research emphasizes on “how to make ERP successful for SMEs”. The researchers have identified various critical success factors in implementation of ERP. The research gap noticed by author is the missing point of view of ERP consultant. This thesis investigates the answer of research question “What are the critical success factors in implementation of ERP system in SMEs in opinion of ERP consultants and acquiring organizations”. The purpose of this study is to identify the highly important and less important factors. The study results will suggest the ERP managers where they have to concentrate more in order to achieve success. Literature is reviewed in order to setup a base for empirical study. Aplenty of work is found related to CSFs, SMEs and ERP. The authors and factors are organized in form of a table that tells which author is agreed upon which factor. Final result of literature review is a list of 14 CSFs. The qualitative research methodology is used to investigate the ERP in Pakistani SMEs. A case study approach is selected because of unified nature of SMEs in Pakistan. A rice mill is selected as a case because it contains maximum SME attributes. The opinion of a Microsoft certified consultant is obtained by a semi-structured interview. Similarly a semi-structured interview is conducted with CIO of SME that acquired ERP. Both the interviewees are asked about all 14 factors, whether they are agree or not and why. The collected evidences then analyzed by tabulation. The factors upon which both the participants found agreed, taken as highly important. Similarly the factors upon which both participants found disagree, taken as less important. Study results present a grid with four quadrants, the CSFs highly important in opinion of both, the CSFs less important in opinion of both, CSFs important in opinion of consultant but not client, CSFs important in opinion of client but not consultant. In discussion part, the significance of each factor is discussed individually. It is discussed that why some factors are high/less important for SMEs in Pakistan. The study output communicates a message that the success of ERP system in SMEs is linked with careful management of five important factors, the project management, top management support, user training and education, consultant participation and ERP teamwork and composition. The ERP consultants and managers can divert their concentration from less important factors such as user involvement, culture readiness and ERP package selection, toward the highly important factors. The limitations of the study are small number of interviews and less people involved, provide an opportunity for future research in this field of information system.

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This Bachelor's thesis takes an outlook on the success factors and the challenges that Born Globals face.

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Este estudo foi conduzido para avaliar a seletividade de herbicidas aplicados em pós-emergência sobre plantas de Panicum maximum, cultivares Tanzânia e Mombaça, e os seus efeitos na qualidade das sementes. Os tratamentos testados (em g ha-1) foram: diclofopmethyl (284), ametryne (1.250), propanil (3.600), chlorimuron-ethyl (15), nicosulfuron (50), bentazon (720) e atrazine (3.000), além de uma testemunha sem aplicação de herbicidas. Foram instalados dois experimentos a campo, um para cada cultivar, no delineamento em blocos casualizados com quatro repetições, e um em laboratório, no delineamento inteiramente casualizado, com 16 repetições. O nicosulfuron foi o herbicida que mais causou injúrias visuais e redução de massa seca de plantas em ambos os cultivares. No cultivar Mombaça, todos os herbicidas reduziram a produção de sementes, mas não afetaram a germinação. Para o cultivar Tanzânia, todos os herbicidas foram seletivos, não afetando a produção e a qualidade fisiológica.

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Laboratory and greenhouse experiments were conducted to determine the effects of drought and salinity stress, temperature, pH and planting depth on yellow sweet clover (Melilotus officinalis) germination and emergence. Base, optimum and ceiling germination temperatures were estimated as 0, 18.47 and 34.60 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited at a potential of -1 MPa, but it was tolerant to salinity. Salinity stress up to 90 mM had no effect over the M. officinalis seed germination, but the germination decreased by increasing the salt concentration. The drought and salinity required for 50% inhibition of maximum germination were 207 mM and -0.49 MPa, respectively. High percentage of seed germination (>92%) was observed at pH = 5-6 and decreased to 80% at acidic medium (pH 4) and to 42% at alkaline medium (pH 9) pH. Maximum seedling emergence occurred when the seeds were placed at 2 cm depth and decreased when increasing the depth of planting; no seed emerged from depths of 10 cm.

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Soil incorporation of crop residues can lead to weed suppression by posing allelopathic and physical effects. Allelopathic potential of the crops sorghum, sunflower, brassica applied as sole or in combination for horse purslane (Trianthema portulacastrum) suppression was evaluated in a pot investigation. Chopped crop residues alone and in combination were incorporated at 6 g kg-1 soil (12 t ha-1), and a weedy check was maintained. Germination traits time to start germination; time to 50% emergence, mean emergence time, emergence index and final germination percentage were negatively influenced by residue incorporation. Crop residues also exerted a pronounced negative influence on the shoot and root length of horse purslane. Significant suppression in leaf and root score and leaf area per plant was also observed. A combination of sorghum and sunflower residues accounted for maximum (71%) seedling mortality. Soil incorporation of allelopathic crop residues can be employed for horse purslane management.

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Decomposing wheat (Triticum aestivum) straw and rhizosphere-infested soil were evaluated for their suppressive activity against horse purslane (Trianthema portulacastrum), a noxious summer weed in Pakistan. Two separate pot studies were carried out. Wheat straw was incorporated at 4, 6 and 8 g kg-1 soil five days before the sowing of horse purslane. Pots without straw incorporation were maintained as control. In a second study, soil was taken from 15 and 30 cm depths from a previously cropped wheat field immediately after its harvest and was used as growing medium. Soil from an intentionally uncropped area of the same field was used as control. Suppressive activity was measured in terms of germination dynamics, seedling growth, and biochemical attributes such as chlorophyll contents, total soluble phenolics, soluble protein and antioxidant enzymes. Germination, seedling growth, chlorophyll contents and soluble protein of horse purslane were all negatively influenced. Higher phenolics and enhanced activities of antioxidant enzymes were noticed in response to wheat residues incorporation and its rhizosphere soil. Both studies established that the phytotoxic influence of wheat straw and wheat-infested rhizosphere soil on horse purslane can further be exploited for horse purslane management as a sustainable approach.

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An understanding of seed germination ecology of weeds can assist in predicting their potential distribution and developing effective management strategies. Influence of environmental factors and seed size on germination and seedling emergence of Convolvulus arvensis (field bindweed) was studied in laboratory and greenhouse conditions. Germination occurred over a wide range of constant temperatures, between 15 and 40 ºC, with optimum germination between 20 and 25 ºC. Time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased with an increase in temperature from 20 ºC, salinity and osmotic stress. However, germination was tolerant to low salt (25 mM) or osmotic stress (0.2 MPa), but as salinity and osmotic stress increased, germination percentage and germination index decreased. Seeds of C. arvensis placed at soil surface showed maximum emergence and decreased as seeding depth increased. Seeds of C. arvensis germinated over a wide range of pH (4 to 9) but optimum germination occurred at pH 6 to 8. Under highly alkaline and acidic pH, time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased. Increase in field capacity caused decreased time to start germination, time to 50% germination and mean germination time but increased germination percentage and germination index. Bigger seeds had low time to start germination, time to 50% germination and mean germination time but high germination percentage and germination index. Smaller seeds were more sensitive to environmental factors as compared to larger or medium seeds. It can be concluded that except for pH, all environmental factors and seed sizes adversely affect C. arvensis as regards seed germination or emergence and germination or emergence traits, and larger seeds result in improved stand establishment and faster germination than small seeds, regardless of moisture stress or deeper seeding depth.

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Rhynchosia capitata is becoming an increasing problem in summer crops, such as cotton, soybean, pearl millet and mungbean in many Asian countries. Laboratory and greenhouse studies have been conducted to determine the effects of several environmental factors on seed germination patterns and seedling emergence of R. capitata. We investigated whether the diverse ecological factors such as temperature, light, salinity, moisture stress, pH, and soil depth affected germination and seedling emergence of R. capitata. Germination increased as temperature increased from 25ºC and significantly reduced at 45ºC. Presence or absence of light did not influence germination. Germination of R. capitata was sensitive to increased salt and moisture stress, as well as to seed burial depth. Only 48% of seeds germinated at 150 mM salt concentration compared to 100% in control (distilled water). Similarly, 15% of seeds germinated at an osmotic potential of ‑0.8 MPa compared to 88% at ‑0.2 MPa. The optimum pH for seed germination of R. capitata was 7 (98% germination), but the seeds also germinated at lower level of pH 5 (85%) and at higher level of pH 10 (75%). In seed burial trial, maximum seedling emergence of 93% occurred at 2 cm depth, and seedling did not emerge from a depth of 12 cm. The high germination ability of R. capitata under a wide range of ecological factors suggests that this species is likely to be the one to cause more problems in a near future, if not managed appropriately.

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Abutilon theophrasti and Barnyardgrass (Echinochloa crus-galli) are major weeds that affect cropping systems worldwide. Laboratory and greenhouse studies were conducted to determine the effects of temperature, pH, water and salinity stress, and planting depth on seed germination and seedling emergence of Velvetleaf and Barnyardgrass. For Velvetleaf, the base, optimum and ceiling germination temperatures were estimated as 5, 35 and 48 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited by a potential of -0.6 MPa, but it was tolerant to salinity. Salinity stress up to 45 mM had no effect on the germination of Velvetleaf, but germination decreased with increasing salt concentration. Drought and salinity levels for 50% inhibition of maximum germination were -0.3 MPa and 110 mM, respectively. Seed germination of Velvetleaf was tolerant to a wide range of pH levels. For Barnyardgrass, the base, optimum and ceiling germination temperatures were estimated as 5, 38 and 45 ºC, respectively. Seed germination was tolerant to drought stress and completely inhibited by a potential of -1.0 MPa. Salinity stress up to 250 mM had no effect on seed germination. Drought and salinity levels for 50% inhibition of maximum germination were -0.5 MPa and 307 mM, respectively. A high percentage of seed germination was observed at pH=5 and decreased to 61.5% at acidic medium (pH 4) and to 11% at alkaline medium (pH 9). Maximum seedling emergence of Velvetleaf and Barnyardgrass occurred when the seeds were placed on the surface of the soil or at a depth of 1 cm.

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Experiments were conducted to evaluate the allelopathic influence of Rhynchosia capitata on germination and seedling growth of mungbean (Vigna radiate) along with identification of the phytotoxic substances responsible for this activity. Water extracts of root, shoot, leaf, fruit and whole plant were prepared by soaking them in water in a ratio of 1:20 (w/v) for 24 h. All the extracts affected germination and seedling growth of mungbean, but higher inhibition was seen with R. capitata leaf water extracts. A linear decrease in the germination characteristics of mungbean was observed with the decrease in the concentration of leaf extract from 5% to 1%. The soil-incorporated residues (1-4% w/w) of R. capitata stimulated the growth of root and hypocotyl at low concentrations, while it inhibited their growth at higher concentrations. Rhynchosia capitata soil-incorporated residues (4% w/w) significantly reduced the seedling vigour index of mungbean in addition to their significant effect on total germination. A significant amount of water-soluble phenolic acids were found in R. capitata plant extracts. The content of total phenolic acids was higher in the leaf extract compared to that of the stem, fruit or root extracts. Two phenolic acids including vanillic acid and 4‑(hydroxymethyl) benzoic acid were found in R. capitata leaf extracts.

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Trianthema portulacastrum is a very problematic summer crop weed and a complete crop failure has been observed because of this weed at high density. The effect of different ecological factors on germination of T. portulacastrum seeds collected in two different years (2009 and 2005) was studied in laboratory experiments. An increase in temperature from 25 to 35 ºC increased germination percentage of T. portulacastrum from 65 to 85%, after which germination started to decrease, reducing to 71.25% at 45 ºC. Trianthema portulacastrum had maximum germination with distilled water compared with different salt solutions and drought stress levels. Germination was significantly minimum at salinity and drought stress level of 250 mM and -0.8 MPa, respectively. Emergence of T. portulacastrum was maximum (86.25%) at 100% field capacity level but decreased sharply as field capacity decreased thereafter, and minimum emergence (30%) was recorded at field capacity level of 25%. Germination of T. portulacastrum was lowest at pH 5 and any increase in pH resulted in increased germination. A pH range of 8 to 10 had statistically similar germination. Sowing depth of 6 cm reduced the emergence of T. portulacastrum to zero. Reduction in emergence was recorded with depth increase from zero to 5 cm. Maximum emergence was recorded from soil surface (0 cm). An increase in temperature, salinity, drought, sowing depth (up to 4 cm) and a decrease in field capacity increased time to start germination/emergence, time to 50% germination/emergence and mean germination/emergence time but decreased germination/emergence index. Seeds collected during 2009 gave higher germination than old seeds collected in 2005. This information might contribute to development of effective control of T. portulacastrum.

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The purpose of this study is to identify factors contributory to success or failure of a microenterprise. Microenterprise is an enterprise with less than10 employees. About 99 % of all Finnish enterprises fall in this category. Earlier studies do not provide a comprehensive view on microenterprise success and failure factors. The theoretical part discusses the definition of success and failure, previous research and results already established about the topic and categories of business environment. The empirical part is founded on quantitative survey results from 204 Finnish microenterprises. The questions of the survey were based on previous surveys, literature and intuition. Both success and failure factors were enquired. Summary of the results was made and the results were compared among successful and unsuccessful enterprises. In open-end questions, the most important factors mentioned to affect enterprise performance positively were "Employees", "Customers" and "Skills, knowledge, education and experience." The most important factors affecting enterprise performance negatively were "Economical situation", "Employees availability and attitudes" as well as "Political decisions and passed laws". In Likert-scale set of questions, the most significant factors from the point of view of enterprise performance were "Product and / or service good quality", "Good reputation of the company" and "Staff's strong skills". The least significant factors were "Effect of marketing and promotion", "Conflicts" and "Differences of points of views of different generations". By Likert-scale set of questions, it was also tested which operations the enterprises perform, and according to the results, successful enterprises found "Performing a market research", "Use of distribution channel in sales" and "Expanding to new markets" less important than unsuccessful enterprises. The tests proved that the age of the enterprise correlates with the level of success of the enterprise: The younger the enterprise, the more successful it is. In addition, the results show that if the enterprise is family based, the less successful it is. In addition, there was also slight correlation between success and the level of growth, indicating that higher the level of growth the more successful the enterprise is. From the business environment point of view, the key finding was that internal factors affect more on the success of an enterprise than external factors, and that external factors affect more on the failure of an enterprise than internal factors.