Relevant bibliographies by topics / Cowpea – Growth

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Cowpea – Growth'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Cowpea – Growth.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Cowpea – Growth"

1

Wang, Guangyao, Milton E. McGiffen, and Jeff D. Ehlers. "Competition and growth of six cowpea (Vigna unguiculata) genotypes, sunflower (Helianthus annuus), and common purslane (Portulaca oleracea)." Weed Science 54, no. 5 (October 2006): 954–60. http://dx.doi.org/10.1614/we-06-045r.1.

Full text
Abstract:
Varietal growth habit could play a key role in the competitiveness of crop plants with weeds. The relative competitiveness of two erect, two semierect, and two prostrate cowpea genotypes with a tall-growing (common sunflower) or a low-growing (common purslane) species was evaluated in 12 replacement-series experiments conducted in 2003 and 2004. Growth analysis of the six cowpea genotypes and two weed species were also conducted to investigate the relationship of competitiveness and growth. Cowpea genotype and competitor biomass were used to calculate relative yield total (RYT) and aggressivity indices (AI). RYT and AI means of six cowpea genotypes were compared using ANOVA, and an isotonic regression was used to confirm the relative competitive superiority of the cowpea growth types. All cowpea genotypes had similar RYTs when grown with sunflower or common purslane, indicating that cowpea used the same resources as sunflower or purslane. When grown with sunflower, erect and semierect genotypes had higher AI than prostrate genotypes. When grown with purslane, erect and prostrate genotypes had higher AI than semierect genotypes. The results were confirmed by isotonic regression tests on the respective AI order. Correlation and regression between AI and growth parameters showed that the relative growth rate (RGR), leaf area ratio (LAR), and height growth rate (HGR) explained 92% of the variation of AI when cowpeas were grown with sunflower and that leaf weight ratio (LWR) and biomass explained 82% of the variation of AI when cowpeas were grown with purslane. These experiments indicate that cowpea genotypes differ in their ability to compete with purslane or sunflower. Erect genotypes were the most competitive, suggesting that an erect growth habit may be more effective in suppressing weeds than a semierect or prostrate growth habit. These results are consistent with field experiments on the competitiveness of erect, semierect, and prostrate cowpea genotypes.
APA, Harvard, Vancouver, ISO, and other styles
2

Marsh, Lurline E., and Mohsen Dkhili. "GERMINATION AND GROWTH OF COWPEA AND PIGEONPEAS AT CONTROLLED LOW TEMPERATURES." HortScience 27, no. 6 (June 1992): 682f—682. http://dx.doi.org/10.21273/hortsci.27.6.682f.

Full text
Abstract:
Twenty cowpea (Vigna unguiculata) and 10 early maturing pigeonpea (Cajanus cajan) genotypes were grown at 20/10 C, and 17/10 C day/night and 16 hr. photoperiod to assess their germination and growth. At 20/10 C eighteen cowpea genotypes including the line MN13, and the cultivar, Pinkeye Purple Hull commenced germination at 6 days after planting and showed at least 80% germination 21 days later. Generally, genotypes did not differ significantly in germination and seedling growth up to 45 days later. At 17/10 C two of the cowpea genotypes IT 82E-16 and IT 84E-124 attained at least 90% germination within 21 days after planting. Seedling, growth of these genotypes did not differ and plants began to die 70 days after planting. The pigeonpeas at 17/10 C commenced germination at 9-10 days like many of the cowpeas. Most had at least 50% germination and did not differ in shoot elongation and leaf production. All pigeonpeas flowered between 109 and 136 days after planting and produced pods with immature seeds.
APA, Harvard, Vancouver, ISO, and other styles
3

Sari, Lili Agustina. "GROWTH AND RESULTS OF CORN AND NUTS IN THE INTERCROPPING SYSTEM." JURNAL PERTANIAN 10, no. 2 (October 22, 2019): 102. http://dx.doi.org/10.30997/jp.v10i2.2023.

Full text
Abstract:
The purpose of this study was to determine the growth and yield of corn and cowpea after planting in the intercropping system. Conducting research at the Kalitirto Agricultural Research and Development (KP4) Educational Garden, Berbah, Yogyakarta friend. A Complete Randomized Block Design with 3 replications was used in the study. Experimental intercropping of corn and cowpea based on additive series system. The first factor is the population of cowpea is without cowpea, 1 row, 2 rows, and 3 rows of cowpea. The second factor is the spacing is 100 cm x 20 cm and 80 cm x 25 cm. Research on cowpea monoculture as a comparison.The results obtained (1) insertion of cowpea, and spacing of corn did not affect the yield of corn per hectare, but affect the yield of cowpea. (2) The combination of 100 cm x 20 cm corn spacing treatment with the insertion of 2 rows of cowpea gives the highest Land Equity Ratio value of 1.42.
APA, Harvard, Vancouver, ISO, and other styles
4

Sebetha, E. T., and A. T. Modi. "Influence of Management Practices on Selected Cowpea Growth Attributes and Soil Organic Carbon." Journal of Agricultural Science 8, no. 11 (October 11, 2016): 20. http://dx.doi.org/10.5539/jas.v8n11p20.

Full text
Abstract:
<p>Cowpea is a multi-purpose nitrogen fixing crop that can be grown as a vegetable, grain legume and a fodder. The objectives of this study were to investigate the growth response of cowpea to different cropping systems at different locations and determine nitrogen fertilization on cowpea growth and soil organic carbon content. Three cropping systems were used, namely, maize-cowpea rotation, cowpea monocropping and maize-cowpea intercropping at three locations (Potchefstroom, Taung, and Rustenburg) in South Africa during 2011/12 and 2012/13 planting seasons. Nitrogen fertilizer was applied at two rates where no application was the control at all locations and application according to soil analysis recommendation for maize requirement was applied at each location. The variables measured for cowpea growth were days to 100% flowering and physiological maturity, number of leaves and nodules per cowpea plant. Soil organic carbon was determined for each treatment. The results showed that, maize-cowpea rotation and monocropping reached days to 100% flowering and maturity significantly earlier compared to intercropping. Cowpea planted at Potchefstroom and Rustenburg reached days to 100% flowering and physiological maturity significantly earlier than cowpea planted at Taung. Cowpea planted at Taung had significantly higher number of nodules per plant than cowpea planted at Potchefstroom and Rustenburg. There was also a positive correlation between soil organic carbon and cowpea growth. It is concluded that the positive effect of cowpea in agronomic systems is enhanced by the correct cropping system, although it is affected by location.</p>
APA, Harvard, Vancouver, ISO, and other styles
5

Wang, Guangyao, Milton E. McGiffen, John L. Lindquist, Jeff D. Ehlers, and Ivan Sartorato. "(316) Simulation Study of the Competitive Ability of Erect, Semi-erect, and Prostrate Cowpea Genotypes." HortScience 41, no. 4 (July 2006): 1044C—1044. http://dx.doi.org/10.21273/hortsci.41.4.1044c.

Full text
Abstract:
Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics, and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterized, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus), and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM did not simulate biomass production and leaf area index (LAI) of cowpea and purslane well, probably due to a lack of published data on purslane physiology. INTERCOM simulated the competition of cowpea genotypes and sunflower accurately. The simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habits on final biomass production of cowpea and sunflower. The model suggested that the erect growth habit was more competitive than the semi-erect and prostrate growth habits when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass.
APA, Harvard, Vancouver, ISO, and other styles
6

Xu, Nicole W., Shizhong Xu, and Jeff Ehlers. "Estimating the Broad-Sense Heritability of Early Growth of Cowpea." International Journal of Plant Genomics 2009 (June 7, 2009): 1–4. http://dx.doi.org/10.1155/2009/984521.

Full text
Abstract:
Cowpea is an important tropical crop. It provides a large proportion of the food resource for the African human population and their livestock. The yield and quality of cowpea have been dramatically improved through traditional breeding strategies for the past few decades. However, reports of heritability estimates for early growth of cowpea are rare. We designed a simple experiment to estimate the broad-sense heritability of early growth. We randomly selected 15 cowpea varieties among a total of 5000 cowpea accessions maintained in the cowpea breeding facility at the University of California, Riverside to examine the genetic determination of early growth of cowpea (measured as the height at day five after seeding). The estimated broad-sense heritability on the individual plant basis is 0.2190. However, the corresponding estimate on the plant mean basis (average of four plants) is 0.5198, which is very high for a quantitative trait. The high heritability may explain why traditional breeding for cowpea growth is so effective. Since the design of experiment and method of data analysis are novel, this report can serve as an educational note for students in the area of quantitative genetics and plant breeding.
APA, Harvard, Vancouver, ISO, and other styles
7

Wang, Guangyao, Milton E. McGiffen, Jeff D. Ehlers, and Edilene C. S. Marchi. "Competitive ability of cowpea genotypes with different growth habit." Weed Science 54, no. 4 (August 2006): 775–82. http://dx.doi.org/10.1614/ws-06-011r.1.

Full text
Abstract:
Growth habit is an important determinant of competitive ability in legume crops. Erect ‘Iron-Clay’ (IC), semi-erect ‘IT89KD-288’ (288), and prostrate ‘UCR 779’ (779) cowpea genotypes were planted with four densities of common sunflower or common purslane to determine which cowpea growth habit is more competitive to these weeds having markedly different statures. Both sunflower and purslane reduced cowpea relative growth rate (RGR) but at different phases of the growing season. Low-growing purslane had an effect in the earlier part of the season, and sunflower decreased cowpea RGR in the middle of growing season. RGR of genotype IC was the least affected and genotype 779 the most reduced by sunflower. Cowpea apparently compensated for early season purslane competition by increasing RGR after purslane flowering, with RGR for the IC genotype increasing the most and 779 increasing the least. All cowpea genotypes caused a similar reduction in sunflower biomass accumulation; but purslane biomass was most reduced by genotype IC and least affected by genotype 288. Erect genotype IC is more competitive due to its taller stature, greater height growth rate, and higher position of maximal leaf area density, despite a lower photosynthetic rate and light use efficiency than the other cowpea genotypes. Our results suggest that erect cowpea growth habit may be generally more competitive with weeds compared to semi-erect or prostrate growth habit.
APA, Harvard, Vancouver, ISO, and other styles
8

Akanji, AM, OE Fasina, and AM Ogungbesan. "Effect of raw and processed cowpea on growth and heamatological profile of broiler chicken." Bangladesh Journal of Animal Science 45, no. 1 (April 24, 2016): 62–68. http://dx.doi.org/10.3329/bjas.v45i1.27490.

Full text
Abstract:
A study was carried out to look at the utilization of cowpea based diets on performance characteristics and haematology of broiler chickens. Raw cowpea, dehulled cowpea, dehulled cooked cowpea and dehulled roasted cowpea grains were fed to broiler chickens in an eight week feeding trial. A total of two hundred (200) day old unsexed broiler chicks of Marshall strain were allotted into five dietary treatments.?Feed intake and growth were significantly (P < 0.05) reduced in birds fed raw cowpea and dehulled cowpea respectively. The feed conversion efficiency (FCE) and protein efficiency ratio (PER) also followed a similar pattern. Non significant (P > 0.05) differences were however obtained in weight gain, FCE and PER of birds fed control diet and those fed dehulled cooked cowpea in this study. Birds fed dehulled roasted cowpea also had marginal reductions in weight gain, FCE and PER when compared to those fed dehulled cooked cowpea based diet. The haematological studies showed lower (P < 0.05) values of haemoglobin, red blood cells, packed cell volume and white blood cells of birds fed raw cowpea and dehulled cowpea respectively. The best significant indices in this study were however obtained in birds fed dehulled cooked cowpea.Bang. J. Anim. Sci. 2016. 45 (1): 62-68
APA, Harvard, Vancouver, ISO, and other styles
9

IDERAWUMI, ABDULRAHEEM MUKHTAR. "Effect of cowpea on growth and yield parameter in a maize-cowpea intercrop." Journal of Management and Science 1, no. 1 (June 30, 2014): 37–42. http://dx.doi.org/10.26524/jms.2014.5.

Full text
Abstract:
An experiment was carried out during the raining season of the year 2011 at the Teaching and Research Farm of Oyo State College of Education (Now Emmanuel Alayande College of Education, Oyo), Lanlate Campus, to investigate the effect of geometric row arrangement on the growth and yield of cowpea in a maize-cowpea intercrop. There were 1:1, 1:2 and 2:1 maize/cowpea row arrangement with a sole crop of cowpea as control. The experiment was laid on out in a Random Complete Block Design (RCBD) with three replicates, No significant difference among the growth parameter (plant height, number of leaves and number of branches) intercropped and the sole cowpea plants (p<0.05). However cowpea intercropped with maize at 1:1 row arrangement recorded highestgrain yield per plant and consequently per hectare than those of 1:2 and 2:1 row arrangement, through not significantly difference from them. It is hereby recommend that cowpea and maize should be planted at 1:1 row arrangement.
APA, Harvard, Vancouver, ISO, and other styles
10

OLIVEIRA, LEANDRO BARBOSA DE, RODRIGO LUIZ NEVES BARROS, WELLITON BARROS DE MAGALHÃES, LEONARDO OLIVEIRA MEDICI, and CARLOS PIMENTEL. "COWPEA GROWTH AND YIELD IN SOLE CROP AND INTERCROPPED WITH MILLET." Revista Caatinga 30, no. 1 (March 2017): 53–58. http://dx.doi.org/10.1590/1983-21252017v30n106rc.

Full text
Abstract:
ABSTRACT The objective of this work was to evaluate the growth and yield of cowpea grains in different intercropping systems with millet, in wet and dry seasons. The experiments were performed in the experimental field of the Department of Plant Science of the Federal Rural University of Rio de Janeiro, Brazil, using a randomized block design with three replications and five treatments: T1- sole crop of millet; T2- sole crop of cowpea; T3- intercrop of millet (1 row) and cowpea (1 row) with 0.5 m between rows (1Mx1C-0.50); T4 - intercrop of millet (1 row) and cowpea (1 row) with 0.75 m between rows (1Mx1C-0.75); and T5 - intercrop of millet (1 row) and cowpea (2 rows) with 0.5 m between rows (1Mx2C-0.50). The cowpea shoot dry weight, root dry weight, number and dry weight of nodules, grain yield and 1000-grain weight, and the millet fresh weight, shoot dry weight, grain yield and 1000-grain weight were evaluated. The land-use efficiency index (LUE) showed significant differences in yield between the sole crop of cowpea and the intercropping system, with greater grain weight in the intercrop 1Mx2C-0.50. On the other hand, the intercrop 1Mx1C-0.75 was not recommended for the study conditions.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Cowpea – Growth"

1

Nelson, Suzanne Cathleen. "Genotype and cropping system effects on cowpea growth and yield." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186596.

Full text
Abstract:
Genotype X cropping system interactions may complicate the plant breeders' task of increasing crop yields, since selection and improvement in one cropping system may not result in improved performance in a different cropping system. Field experiments were conducted in 1990 and 1991 to examine the effects of cowpea (Vigna unguiculata (L.) Walp.) genotypes and cropping systems on cowpea yield, yield components, biomass, and leaf area. When cowpea was grown in sole crop and in intercrop with pearl millet (Pennisetum americanum (L.) Leeke), a significant genotype X cropping system interaction for seed yield occurred in both years. In sole crop, 'California Blackeye 46' (CB46) yielded more than 'Tohono O'odham' (TOC). By contrast, in intercrop, there was no difference in yield between genotypes in 1990, but TOC outyielded CB46 in 1991. More vegetative biomass and leaf area was produced by TOC than CB46 and more was produced in sole crop than intercrop. In intercrop, TOC produced more leaf area in the furrow and higher in the intercrop canopy than CB46. TOC had a more negative effect on millet than CB46. In intercrops differing in row-spatial arrangement (within- and between-row intercrops), TOC outyielded CB46 in both the within- and between-row intercrops, and more yield was produced in the between-row than within-row intercrop. To identify plant traits associated with cowpea seed yield under intercropping, three F₂ cowpea populations were grown in intercrop with millet. All three yield components (pod number, seeds per pod, and mean seed weight) were significantly correlated with cowpea seed yield. The number of pods accounted for most of the variation in seed yield. There was a negative association between seeds per pod and mean seed weight. Plant length, number of nodes, and number of branches were also correlated with seed yield, as were the number of pods produced on basal and distal branches and from the longest (> 10 cm) internode category. Plant traits associated with yield in intercrop may differ from those associated with yield in sole crop. Hence, selection criteria for indirectly selecting yield will differ between cropping systems.
APA, Harvard, Vancouver, ISO, and other styles
2

Makoi, JHJR, SBM Chimphango, and FD Dakora. "Effect of legume plant density and mixed culture on symbiotic N2 fixation in five cowpea (Vigna unguiculata L. Walp.) genotypes in South Africa." Symbiosis, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001476.

Full text
Abstract:
Abstract A field experiment involving two plant densities (83,333 and 166,666 plants per hectare), two cropping systems (monoculture and mixed culture) and five cowpea (Vigna unguiculata L. Walp.) genotypes (3 farmer-selected varieties: Bensogla, Sanzie and Omondaw, and 2 breeder-improved cultivars: ITH98-46 and TVuI509) was conducted for two years in 2005 and 2006 at Nietvoorbij (33°54S, 18°14E), Stellenbosch, South Africa, to evaluate the effect of these treatments on the growth and symbiotic performance of cowpea. The results showed that, of the five cowpea genotypes, plant growth and N2 fixation were significantly greater in the three farmer-selected varieties (Sanzie, Bensogla and Omondaw) relative to the two improved cultivars (ITH98-46 and TVuI509). Furthermore, plant growth and symbiotic performance (measured as tissue N concentration, plant N content, 15N natural abundance and N-fixed) were significantly (P:50.05) decreased by both high plant density and mixed culture (intercropping). However, the %Ndfa values were significantly (P:S0.05) increased by both high plant density and mixed culture compared to low plant density or monoculture (or monocropping). Whether under low or high plant density, the cv. Sanzie was found to accumulate significantly greater total N per plant in both 2005 and 2006, followed by the other two farmer varieties relative to the improved cultivars. Similarly, the actual amount ofN-fixed was much greater in cv. Sanzie, followed by the other farmer varieties, under both low and high plant density. The data also showed better growth and greater symbiotic N yield in cowpea plants cultivated in monoculture (or low plant density) relative to those in mixed culture (or high plant density). Our data suggest that optimising legume density in cropping systems could potentially increase N2 fixation in cowpea, and significantly contribute to the N economy of agricultural soils in Africa.
APA, Harvard, Vancouver, ISO, and other styles
3

Belane, AK, and FD Dakora. "Measurement of N, fixation in 30 cowpea (Vigna unguiculata L. Walp.) genotypes under field conditions in Ghana, using the 15N natural abundance technique." Balaban, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001672.

Full text
Abstract:
Abstract In 2005 and 2006, 30 and 15 cowpea genotypes were respectively evaluated for plant growth and symbiotic performance at Manga in Northern Ghana, in order to identify Nz-fixing potential of these cowpea genotypes as source of N for cropping systems. The results showed differences in biomass production by the 30 or 15 cowpea genotypes. In 2005, cultivars Fahari, Mchanganyiko, IT97K-499-39, IT93K-2045-29 and IT84S-2246 produced the most shoot biomass, while Apagbaala, Brown Eye, ITH98-46, Vita 7 and Iron Grey produced the least. Of the 15 genotypes tested in 2006, cv. TVu1l424 produced the largest amount of biomass, and ITH98-46, the least. Isotopic analysis of 15N in plant parts also revealed significant differences in 1)15N of the cowpea genotypes studied. As a result, the percent N derived from fixation (% Ndfa) also differed among the cowpea genotypes tested in 2005, with only 5 out of the 30 cultivars obtaining over 50% of their N from symbiotic fixation. Whether expressed as mg Nplant' or kg N.ha-I , the levels of Nz fixation by the cowpea genotypes varied considerably during 2005 and 2006, with values ofN contribution ranging from 14.1 kg N.ha-1 by cv. TVul509 to 157.0 kg N.ha-1by IT84S-2246 in 2005. The amounts ofN-fixed in 2006 ranged from 16.7 kg N.ha-1 by cv. ITH98-46 to 171.2 kg N.ha-1 by TVu11424, clearly indicating genotypic differences in symbiotic N yield. Re-evaluating 15 out of the 30 cowpea genotypes for Nz fixation in 2006, revealed higher % Ndfa values (>50%) in all (15 cowpea genotypes) relative to those tested in 2005, indicating greater dependence on Nz fixation for their N nutrition even though, the actual amounts of fixed-N were lower in 2006. This was due, in part, to reduced plant biomass as a result of very late sampling in 2006, close to physiological maturity (72 DAP in 2006 vs. 46 DAP in 2005) when considerable leaf matter was lost. The amount ofNfixed in 2006 can therefore be considered as being under-estimated.
APA, Harvard, Vancouver, ISO, and other styles
4

Kambonde, Lovisa Hinandyooteti. "Activation of oxidoreductases in millet and cowpea grains improves protein utilization for growth." Diss., Connect to online resource - MSU authorized users, 2006.

Find full text
Abstract:
Thesis (M. S.)--Michigan State University. Dept. of Food Science and Human Nutrition, 2006.
Title from PDF t.p. (viewed on June 19, 2009) Includes bibliographical references (p. 67-70). Also issued in print.
APA, Harvard, Vancouver, ISO, and other styles
5

Thobatsi, Jacob Thobatsi. "Growth and yield responses of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) in an intercropping system." Diss., Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-10122009-184005.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Makoi, Joachim HJR. "Seed flavonoid concentration in cowpea genotypes and the effect of plant density on growth, N₂ fixation and rhizosphere phosphatases and grain yield of cowpea intercropped with sorghum." Thesis, Cape Peninsula University of Technology, 2009. http://hdl.handle.net/20.500.11838/727.

Full text
Abstract:
Thesis (DTech (Faculty of Applied Sciences)--Cape Peninsula University of Technology, 2009
A 3-factorial experiment involving two cowpea densities (83,000 and 167,000 plants.ha-1), two cropping systems (i.e. monoculture and mixed culture) and five cowpea genotypes (i.e. three farmer-selected cultivars, Bensogla, Sanzie and Omondaw and two improved varieties, ITH98-46 and TVu1509) was conducted in the field for two consecutive years in 2005 and 2006. The aim was to assess the effect of plant density, cropping system and cowpea genotypes on: (i) chlorophyll and gas-exchange, (ii) rhizosphere mineral concentration and tissue uptake of nutrients, (iii) acid and alkaline phosphatase activities in the rhizosphere, (iv) plant growth and symbiotic performance, and (v) concentration of flavonoids and anthocyanins in seed extracts and plant organs and their effect on pest infestation and diseases. The results showed that high plant density (167,000 plants.ha-1) and mixed culture significantly decreased gas-exchange parameters, leaf chlorophyll content, 13C and %C in both cowpea and sorghum plants compared with low plant density (83,000 plants.ha-1) and monoculture. The data also showed significantly higher 13C and lower %C in ITH98-46 and TVu1509 compared with Bensogla, Omondaw and Sanzie genotypes with a significant correlation between 13C and water-use efficiency. At harvest, grain yield of cowpea and sorghum was significantly decreased by high plant density and mixed culture compared with low plant density and monoculture. Sanzie genotype was generally superior in grain yield (2,550 kg.ha-1) followed by cvs. Omondaw and Bensogla (2,250 and 2,150 kg.ha-1, respectively) compared with the improved cultivars. Sorghum plants in mixture with cv. TVu1509 or cv. ITH98-46 performed better (1,570 and 1,550 kg.ha-1, respectively) compared with those in mixture with other cultivars. The results also showed greater land equivalent ratio (LER = 1.42 to 1.52), suggesting that mixed culture produced greater total yields per unit land area compared with monoculture.
APA, Harvard, Vancouver, ISO, and other styles
7

Bock, Eva. "Deposition and growth of various nanomaterials at nanostructured interfaces." [S.l. : s.n.], 2009. http://nbn-resolving.de/urn:nbn:de:bsz:16-opus-89466.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Neves, AntÃnia Leila Rocha. "Irrigation of cowpea with saline water at different growth stages and their effects on the plant and soil." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5227.

Full text
Abstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
A sensibilidade à salinidade varia com o estÃdio de desenvolvimento da cultura. O feijÃo-de-corda [Vigna unguiculata (L.) Walp.] constitui uma das principais culturas, em diversas regiÃes semi-Ãridas do mundo. Avaliou-se o efeito da irrigaÃÃo com Ãgua salina, aplicada em diferentes estÃdios de desenvolvimento de plantas de feijÃo-de-corda. O experimento foi conduzido no campo, e obedeceu ao delineamento em blocos ao acaso, com cinco tratamentos (T1, T2, T3, T4 e T5) e cinco repetiÃÃes. O feijÃo-de-corda foi cultivado no espaÃamento de 0,8 m entre linhas e 0,3 m entre plantas, com duas plantas por cova. Os tratamentos utilizados foram: T1 - plantas irrigadas com Ãgua do poÃo (CEa de 0,8 dS m-1) durante todo o ciclo; T2 - Ãgua salina com CEa de 5,0 dS m-1, com aplicaÃÃo iniciada apÃs a germinaÃÃo e permanecendo atà o final do ciclo; T3 - Ãgua salina com CEa de 5,0 dS m-1, da semeadura atà 22 dias apÃs o plantio (DAP), correspondendo Ãs fases de germinaÃÃo e crescimento inicial, e Ãgua do poÃo no restante do ciclo; T4 - Ãgua salina com CEa de 5,0 dS m-1, aplicada de 23 a 42 DAP (fase de intenso crescimento vegetativo atà a prÃ-floraÃÃo), e Ãgua do poÃo nas demais fases do ciclo; T5 - Ãgua do poÃo da semeadura atà 42 DAP e Ãgua salina (CEa de 5,0 dS m- 1) aplicada a partir dos 43 DAP (floraÃÃo e frutificaÃÃo). Foram avaliadas a cobertura vegetal do solo, crescimento vegetativo, fotossÃntese, transpiraÃÃo, condutÃncia estomÃtica, produtividade, partiÃÃo de matÃria seca, os teores, os totais extraÃdos e a distribuiÃÃo dos nutrientes na planta, a eficiÃncia nutricional, eficiÃncia no uso da Ãgua e o acÃmulo de sais no solo. A irrigaÃÃo com a combinaÃÃo de Ãgua do poÃo com Ãgua salina reduziu o acÃmulo de sais no solo, em relaÃÃo ao T2. O T2 reduziu as taxas de fotossÃntese e transpiraÃÃo, em relaÃÃo ao T1. O T3 provocou reduÃÃo das trocas gasosas somente na primeira mediÃÃo, enquanto, que similar aplicaÃÃo nos outros estÃdios (T4 e T5) nÃo provocou reduÃÃes significativas nas trocas gasosas das plantas. O T2 inibiu o crescimento vegetativo da planta, enquanto o T3 provocou retardo no desenvolvimento da planta. Os tratamentos T2 e T3 provocaram reduÃÃes significativas no nÃmero de vagens e na produÃÃo de sementes por planta, em relaÃÃo aos demais tratamentos. Por outro lado, os tratamentos T4 e T5 nÃo afetaram o crescimento e a produtividade da cultura, sendo que o T4 causou aceleraÃÃo no ciclo reprodutivo da cultura. Os minerais foram extraÃdos pelo feijÃo-de-corda na seguinte ordem decrescente: N > K > Cl > Ca > Na > P > Fe > Zn > Mn > Cu, no entanto, o T2 reduziu a extraÃÃo da maioria dos elementos analisados, com exceÃÃo do Na e Cl. Os minerais Na, Cl, K, Ca, Fe e Mn permaneceram preferencialmente nas partes vegetativas enquanto N e P foram exportados em maiores proporÃÃes pelos frutos. O T3 reduziu a eficiÃncia de utilizaÃÃo da maioria dos nutrientes. O T2 reduziu a eficiÃncia agronÃmica de utilizaÃÃo de N, P e K, entretanto nÃo afetou a eficiÃncia de utilizaÃÃo dos nutrientes extraÃdos pelas plantas.
The sensitivity of crops to salinity often changes from one growth stage to another. Cowpea [Vigna unguiculata (L.) Walp.] is an important crop specie cultivated in different semi-arid regions of the world. The objective of this work was to evaluate the effect of the irrigation with saline water, applied at different growth development stages of cowpea. The experiment was set up in the field, during the dry season. A completely randomized block design, with five treatments (T1, T2, T3, T4 and T5) and five repetitions, was adopted. The distance between lines and plants were 0.8 m and 0.3 m, respectively, with two plants per hole. The treatments studied were: T1 - Groundwater with electrical conductivity (ECw) of 0.8 dS m-1 during the whole crop cycle; T2 - Saline water (ECw = 5.0 dS m-1) during the whole crop cycle, starting after germination; T3 - Saline water (ECw = 5.0 dS m-1) from sowing until the 22th day after sowing (germination and initial growth) and groundwater in remaining stages of the crop cycle; T4 - Saline water (ECw = 5.0 dS m-1) from the 23th to the 42nd day after germination (intense growth and pre-flowering), and groundwater irrigation for the remaining growth stages. T5 - Groundwater from sowing to the 42nd day after sowing and saline water (ECw = 5.0 dS m-1) during flowering and pod-filling stages. Soil coverage, gas exchange, vegetative growth and crop yield were measured. The mineral concentration and quantity of nutrient removed from the soil, as well as the nutrient use efficiency and salt accumulation in soil were also determined. The irrigation with combination of groundwater and saline water reduced the salt accumulation in soil, in relation to continuous use of saline water. The continuous application of water with ECw of 5.0 dS m-1 (T2) reduced the rates of photosynthesis and transpiration, in relation to the well water (T1). Plants of the treatment 3 showed reduction in gas exchanges only in the first measurement, while the saline water application in other growth stages (T 4 and T5) did not provoke significant reductions in leaf in the gas exchanges of the plants. It was found that the continuous use of saline water inhibits plant growth, while the irrigation with saline water during germination and initial growth causes retardation in plant development. For treatments 2 and 3, reduction in the number of pods and in seed production was verified. Irrigation with saline water from the 23rd to the 42nd day (T4) and from the 43rd to the 63rd (T5) day after sowing did not affect reproductive and vegetative growth, but the saline water application in the pre-flowering (T4) caused anticipation of reproductive cycle. Cowpea plants removed the minerals analyzed in the following decreasing sequence: N > K > Cl > Ca > Na > P > Fe > Zn > Mn > Cu, but the continuous use of saline water (T2) reduced the total extracted for the most nutrients, except for Na e Cl. The minerals Na, Cl, K, Ca, Fe and Mn were distributed preferentially to vegetative plant parts, while the most of N and P were exported in the pods. The irrigation with saline water during germination and initial growth stage (T3) reduced the mineral use efficiency of most of analyzed nutrients. The continuous application of saline water (T2) reduced the agronomic efficiency of the fertilizer application (N, P and K), but it did not affect the nutrient use efficiency by the plants.
APA, Harvard, Vancouver, ISO, and other styles
9

Belane, AK, and FD Dakora. "Symbiotic N2 fixation in 30 field-grown cowpea (Vigna unguiculata L. Walp.) genotypes in the Upper West Region of Ghana measured using 15N natural abundance." Springer, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001434.

Full text
Abstract:
Abstract In this study, 30 cowpea genotypes were assessed for symbiotic N2 fixation in 2005, and 15 of them were reevaluated in 2006 using the 15N natural abundance technique. Shoot dry matter yield of cowpea genotypes increased significantly in cvs. Vuli-1, Glenda, IT93K-2045- 29, IT90K-59, Omondaw, Apagbaala, and IT84S-2246 in 2005 producing about 3.0 to 3.6-fold more biomass relative to cv. Vallenga. In 2006, seven out of the 15 cowpea genotypes tested (namely, IT97K-499-39, TVu11424, Botswana White, IT84S-2246, Sanzie, Brown Eye, and Glenda) also produced more dry matter than cv. CH14. Shoot δ15N values ranged from −0.58‰ to 1.49‰ in 2005, and −1.51‰ to 1.40‰ in 2006, and these resulted in %Ndfa values of 63.5–86.7% and 56.2–96.3%, respectively. The amount of N-fixed was 49–178 kg N ha−1 in 2005 and 62–198 kg N ha−1 in 2006. Furthermore, there was a direct relationship between the level of symbiotic N nutrition and plant growth, and between grain yield and amount of N-fixed in 2005 and 2006. As a result, genotypes that fixed the most N also produced the largest biomass and the greatest amount of grain yield. The observed relationship between N2 fixation and biomass confirmed our view that cowpea (and other grain legumes) can be concurrently selected for higher N2 fixation, superior plant growth, and greater grain yield. The high levels of N-fixed by many of the cowpea genotypes in this study suggest that they can contribute large amounts of N to cropping systems in African agriculture.
APA, Harvard, Vancouver, ISO, and other styles
10

Dookie, Edris Kamal. "Effects of limestone applications and tillage on Cowpea (Vigna unguiculata L. Walp.) growth in acid soils of the intermediate savannahs of Guyana." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72837.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Cowpea – Growth"

1

Riding for the brand: 150 years of Cowden Ranching : being an account of the adventures and growth in Texas and New Mexico of the Cowden Land & Cattle Company. Norman: University of Oklahoma Press, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Maua, James Odhiambo. Establishment and early growth of Prosopis juliflora and Azadirachta indica interplanted with greengrams, cowpeas, and lab-lab beans under irrigated conditions at Bura. Nairobi, Kenya: Kenya Forestry Research Institute, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Riding For The Brand 150 Years Of Cowden Ranching Being An Account Of The Adventures And Growth In Texas And New Mexico Of The Cowden Land Cattle Company. University of Oklahoma Press, 2009.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Cowpea – Growth"

1

Liu, R., and E. L. Schmidt. "Isolation and characterization of cowpea (Vigna unguiculata) lectin." In The Rhizosphere and Plant Growth, 187. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3336-4_38.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Martínez-García, J. F., and J. L. García-Martínez. "Phytochrome modulation of gibberellin metabolism in cowpea epicotyls." In Progress in Plant Growth Regulation, 585–90. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2458-4_70.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Maia, Josemir Moura, Cristiane E. C. Macedo, Ivanice da Silva Santos, Yuri Lima Melo, and Joaquim A. G. Silveira. "Antioxidant Mechanisms Involved in the Control of Cowpea Root Growth Under Salinity." In Saline and Alkaline Soils in Latin America, 415–30. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-52592-7_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Buerkert, Barbara, Joachim Banzhaf, Andreas Buerkert, and Dietrich E. Leihner. "Effects of Natural Savannah Windbreaks and Soil Ridging on Wind Erosion and Growth of Cowpea and Millet." In Wind Erosion in Niger, 87–104. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1618-0_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Nakanishi, Tomoko M. "Real-Time Water Movement in a Plant." In Novel Plant Imaging and Analysis, 39–72. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4992-6_2.

Full text
Abstract:
AbstractThe next approach to research on water was to measure the small amount of water actually moving within a plant. The best method is to utilize radioisotope (RI)-labeled water and measure the radiation from outside of the plant. However, it is rather difficult to label water, since there are only limited kinds of RI for tracing water.When utilizing 18F to trace water movement, another fundamental question to consider was the features that characterize drought-tolerant and drought-sensitive plants. It is natural to suppose that drought-tolerant plants have strong water absorption; therefore, by analyzing the water absorption mechanism of tolerant plants and by introducing this function to sensitive plants, it might be possible to make the sensitive plants more tolerant.However, when water uptake was studied in naturally developed drought-tolerant and drought-sensitive cowpea, selected from 2000 cowpea plants grown in the field of Africa, the result was unexpected. Under normal conditions, the amount of water absorbed by the drought-tolerant strain was much lower than that absorbed by the sensitive strain, as if showing the low capability of water absorption. When a drought condition was introduced, the tolerant strain began to absorb much more water than usual, whereas the sensitive strain could not absorb as much water as before. This result provided us with an important lesson. Analyzing the mechanism of drought tolerance only by comparing the water absorption of tolerant and sensitive plants might not readily reveal the reason for drought tolerance. The features of the naturally produced plants showed us different mechanisms that might not match our expectations developed in the laboratory.Next, we performed water measurements using 15O-labeled water, which has an extremely short half-life of 2 minutes. Here, we found another astonishing result, which was “water circulation” in the plant internode. A tremendous amount of water was always leaking from xylem cells, which had been regarded as a mere pipe to transfer water from the root to the aboveground parts. In another subsequent study, it was shown that the water flowing out from the xylem was pushing out the water already present in the stem and then returning to the xylem again to move upward. The water velocity in the internode was kept constant, and through simulation, it took less than 20 minutes to exchange the water already present in the stem with newly absorbed water.
APA, Harvard, Vancouver, ISO, and other styles
6

"Common Bean and Cowpea." In Growth and Mineral Nutrition of Field Crops, Third Edition, 391–424. CRC Press, 2010. http://dx.doi.org/10.1201/b10160-14.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Souza, Marcelo Ferreira de, José Ivo Soares, Ana Cristina Macedo de Oliveira, Sebastião Erailson de Sousa Santos, Maíres Alves Cordeiro, Jeyce Layse Bezerra Silva, Maria Regina de Oliveira Cassundé, et al. "TOBACCO MIXTURE IN THE FIGHT AGAINST COWPEA APHID DURING THE GROWTH AND DEVELOPMENT OF V. unguiculata." In Ciências Biológicas: Campo Promissor em Pesquisa 4, 67–73. Atena Editora, 2020. http://dx.doi.org/10.22533/at.ed.4042024066.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Kloeppel, Brian D., and Barton D. Clinton. "Drought Impacts on Tree Growth and Mortality of Southern Appalachian Forests." In Climate Variability and Ecosystem Response in Long-Term Ecological Research Sites. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195150599.003.0009.

Full text
Abstract:
The Coweeta LTER Program represents the eastern deciduous forests of the southern Appalachian Mountains in the United States. Coweeta Hydrologic Laboratory was established in 1934 and hence has a long record of climate measurement and vegetation response to both natural and human disturbance (Swank and Crossley 1988). The general climate of the area is classified as marine humid temperate because of high moisture and mild temperatures (Critchfield 1966; Swift et al. 1988). These conditions have favored the evolution of high species diversity in organisms in the southern Appalachians at many levels. In recent years, however, Coweeta has experienced several droughts that have caused significant tree growth reduction and increased mortality rates (Swift et al. 1990; Clinton et al. 1993; Vose and Swank 1994; McNulty and Swank 1995). In this chapter, we describe the general climate and features of Coweeta as well as the impact of droughts on tree growth and mortality. The timescale of this climate variability is annual, with the potential for preexisting soil moisture conditions either providing a buffer or further exacerbating the drought conditions. Mean annual precipitation at Coweeta Hydrologic Laboratory (latitude 35º14' N, longitude 83º26' W) varies from 1798 mm at the base climate station (686 m) to 2373 mm at the high-elevation Mooney Gap climate station (1364 m). Mean annual growing season precipitation, defined as May to October, is 782 mm at the base climate station (figure 3.1). Mean annual streamflow from watershed 18, a low-elevation reference watershed, is 1011 mm or 56% of precipitation (figure 3.1). Short-duration thundershowers at Coweeta are typical for midsummer and fall with occurrences of large rainfalls stimulated by tropical disturbances near the Atlantic or Gulf coasts. Forty-nine percent of the 133 storms each year have a total precipitation amount less than 5 mm, and 69% of the annual precipitation falls with an intensity less than 10 mm per hour. Snow is a minor part of the annual precipitation, averaging 2–5% depending on elevation. Snow cover rarely lasts for more than 3 or 4 days, even on the upper slopes.
APA, Harvard, Vancouver, ISO, and other styles
9

Juo, Anthony S. R., and Kathrin Franzluebbers. "Soils and Sustainable Agriculture : Ecological Considerations." In Tropical Soils. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195115987.003.0018.

Full text
Abstract:
Sustainable agriculture can be defined in many different ways. In industrial nations, sustainable agriculture means improving energy use efficiency, reducing environmental pollution, and increasing and sustaining profitability. For millions of small-holder farmers throughout the tropics, sustainable agriculture means providing basic food needs for the farming family, improving the farmer’s ability to replenish soil nutrients and control soil degradation, and optimizing crop yield per unit area of land. Soil utilization for agricultural production in the tropics during the past two centuries, to a large extent, has been influenced by the technological and economic changes in temperate regions. Research and development for agriculture during the colonial era were mainly focused on the needs of industrial nations, while the production of food crops for the indigenous inhabitants was largely left in the hands of the traditional slash-and-burn cultivators. Large and small cash crop plantations were developed on fertile, high-base-status allophanic and oxidic soils for coffee, cocoa, banana, and sugarcane production throughout the humid and subhumid tropics. Cotton was cultivated on smectitic soils and high-base-status kaolinitic soils in the subhumid and semiarid regions of Africa for the textile industries in temperate regions. In tropical America, cattle ranching, a production system introduced by European immigrants, still occupies most of the fertile flat land today, while food grains are usually cultivated on less fertile land or in shallow soils on steep slopes. In tropical Africa and Latin America, a wide range of food crops, such as maize and beans, potato, cowpea, sorghum, millet, cassava, and yam are mostly produced under the traditional slash-and-burn system of cultivation on less fertile kaolinitic soils. In tropical Asia, the indigenous intensive rice-based agriculture on wet smectitic soil has been practiced over many centuries and has been able to meet the basic food needs for the increasing population in the region. Generally, upland food crop production in the tropics has not kept pace with human population growth in the tropics during the past century. It was not until the 1950s and 1960s, following the independence of many nations in tropical Asia and Africa, that more attention was given to the research and development of food crop production.
APA, Harvard, Vancouver, ISO, and other styles
10

Yehia, Lamis, Joanne Ngeow, and Charis Eng. "PTEN-Related Overgrowth Syndromes." In Overgrowth Syndromes, 163–86. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190944896.003.0009.

Full text
Abstract:
Individuals carrying germline mutations in the tumor suppressor gene phosphatase and tensin homolog (PTEN) may present with diverse clinical phenotypes, grouped under the term of PTEN hamartoma tumor syndrome (PHTS). This chapter will focus on two PHTS conditions: Bannayan-Riley-Ruvalcaba syndrome and Cowden syndrome. The first condition is an autosomal dominant disorder characterized by macrocephaly, intestinal hamartomatous polyposis, vascular malformations, lipomas, hemangiomas, and genital freckling. Other features include developmental delay, hypotonia, and scoliosis. Cowden syndrome is also an autosomal dominant disorder, mainly characterized by multiple hamartomas and high risk of breast, thyroid, and other cancers. PTEN encodes the main inhibitor of the PI3K-AKT pathway, regulating cell growth and proliferation, and protein synthesis. Therefore, germline loss-of-function mutations in this gene lead to excessive growth, particularly affecting connective tissues. Detection of PTEN mutations is critical for clinical management and treatment strategies.
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Cowpea – Growth"

1

"Genetic mechanisms associated with determinate growth habit in cowpea (Vigna unguiculata (L.) Walp.)." In SYSTEMS BIOLOGY AND BIOINFORMATICS. Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 2019. http://dx.doi.org/10.18699/sbb-2019-19.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Ntatsi, Georgia, Christina Vrontani, Maria Vlachou, Eleni Rizopoulou, Christos Fotiadis, Andreas Ropokis, Anastasia Tampakaki, and Dimitrios Savvas. "Impact of different rhizobial strains and reduced N supply on growth and biological N2-fixation in cowpea grown hydroponically." In VII South-Eastern Europe Syposium on Vegetables & Potatoes. University of Maribor Press, 2017. http://dx.doi.org/10.18690/978-961-286-045-5.41.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

"Differential Response of Cowpea Genotypes to Sowing Depth in Relation to Growth Parameters (Vigna unquiculata L. Walp)." In International Conference on Advances in Agricultural, Biological & Environmental Sciences. International Institute of Chemical, Biological & Environmental Engineering, 2015. http://dx.doi.org/10.15242/iicbe.c0715042.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

SILVA, P. C. C., R. M. ARAGÃO, E. A. GUILHERME, R. T. SOUSA, and J. A. G. SILVEIRA. "GROWTH REDUCTION INDUCED BY SALT INHIBIT NITRATE INFLUX IN COWPEA ROOTS BY LOW N-DEMAND (SIGNAL FEEDBACK REGULATION)." In IV Inovagri International Meeting. Fortaleza, Ceará, Brasil: INOVAGRI/ESALQ-USP/ABID/UFRB/INCT-EI/INCTSal/INSTITUTO FUTURE, 2017. http://dx.doi.org/10.7127/iv-inovagri-meeting-2017-res3210531.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

C, AGBALA C., ITELIMA J U, NWADIARO P O, NYAM M A, OGBONNA A I, and ONYIMBA I A. "Growth and yield response of cowpea Vigna unguiculata to bio fertilizers produced from Aspergillus niger and animal waste materials." In Third International Conference on Advances in Bio-Informatics, Bio-Technology and Environmental Engineering- ABBE 2015. Institute of Research Engineers and Doctors, 2015. http://dx.doi.org/10.15224/978-1-63248-060-6-51.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Prabel, B., S. Marie, and A. Combescure. "Dynamic Crack Propagation and Arrest in PWR Pressure Vessel Steel: Interpretation of Experiment With the X-FEM Method." In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26315.

Full text
Abstract:
In the frame of analysis of the pressure thermal shock in a PWR RVP and the associated R&D activities, some developments are performed at CEA on the dynamic brittle propagation and crack arrest. This paper presents a PhD work on the modeling of the dynamic brittle crack growth. For the analyses, an important experimental work is performed on different geometries using a French RPV ferritic steel: Compact Tension specimens with different thickness, isothermal rings under compression with different positions of the initial defect to study a mixed mode configuration, and a ring submitted to thermal shock. The first part of this paper details the test conditions and main results. To propose an accurate interpretation of the crack growth, a viscous-elastic-plastic dynamic model is used. The strain rate influence is taken into account based on Cowper-Symond’s law (characterization was made from Split Hopkinson Pressure Bar tests). To model the crack propagation in the Finite Element calculation, eXtended Finite Element Method (X-FEM) is used. The implementation of these specific elements in the CEA F.E. software CAST3M is described in the second part of this paper. This numerical technique avoids re-meshing, because the crack progress is directly incorporated in the degrees of freedom of the elements crossed by the crack. The last part of this paper compares the F.E. predictions to the experimental measurements using different criteria. In particular, we focused on a RKR (Ritchie-Knott-Rice) like criterion using a critical principal stress in the front of the crack tip during the dynamic crack extension. Critical stress is found to depend on crack speed, or equivalently on strain rate. Good results are reported concerning predictive simulations.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Cowpea – Growth' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography