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Wang, Guangyao, Milton E. McGiffen y Jeff D. Ehlers. "Competition and growth of six cowpea (Vigna unguiculata) genotypes, sunflower (Helianthus annuus), and common purslane (Portulaca oleracea)". Weed Science 54, n.º 5 (octubre de 2006): 954–60. http://dx.doi.org/10.1614/we-06-045r.1.
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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.
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Marsh, Lurline E. y Mohsen Dkhili. "GERMINATION AND GROWTH OF COWPEA AND PIGEONPEAS AT CONTROLLED LOW TEMPERATURES". HortScience 27, n.º 6 (junio de 1992): 682f—682. http://dx.doi.org/10.21273/hortsci.27.6.682f.
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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.
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Sari, Lili Agustina. "GROWTH AND RESULTS OF CORN AND NUTS IN THE INTERCROPPING SYSTEM". JURNAL PERTANIAN 10, n.º 2 (22 de octubre de 2019): 102. http://dx.doi.org/10.30997/jp.v10i2.2023.
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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.
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Sebetha, E. T. y A. T. Modi. "Influence of Management Practices on Selected Cowpea Growth Attributes and Soil Organic Carbon". Journal of Agricultural Science 8, n.º 11 (11 de octubre de 2016): 20. http://dx.doi.org/10.5539/jas.v8n11p20.
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<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>
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Wang, Guangyao, Milton E. McGiffen, John L. Lindquist, Jeff D. Ehlers y Ivan Sartorato. "(316) Simulation Study of the Competitive Ability of Erect, Semi-erect, and Prostrate Cowpea Genotypes". HortScience 41, n.º 4 (julio de 2006): 1044C—1044. http://dx.doi.org/10.21273/hortsci.41.4.1044c.
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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.
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Xu, Nicole W., Shizhong Xu y Jeff Ehlers. "Estimating the Broad-Sense Heritability of Early Growth of Cowpea". International Journal of Plant Genomics 2009 (7 de junio de 2009): 1–4. http://dx.doi.org/10.1155/2009/984521.
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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.
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Wang, Guangyao, Milton E. McGiffen, Jeff D. Ehlers y Edilene C. S. Marchi. "Competitive ability of cowpea genotypes with different growth habit". Weed Science 54, n.º 4 (agosto de 2006): 775–82. http://dx.doi.org/10.1614/ws-06-011r.1.
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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.
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Akanji, AM, OE Fasina y AM Ogungbesan. "Effect of raw and processed cowpea on growth and heamatological profile of broiler chicken". Bangladesh Journal of Animal Science 45, n.º 1 (24 de abril de 2016): 62–68. http://dx.doi.org/10.3329/bjas.v45i1.27490.
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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
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IDERAWUMI, ABDULRAHEEM MUKHTAR. "Effect of cowpea on growth and yield parameter in a maize-cowpea intercrop". Journal of Management and Science 1, n.º 1 (30 de junio de 2014): 37–42. http://dx.doi.org/10.26524/jms.2014.5.
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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.
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OLIVEIRA, LEANDRO BARBOSA DE, RODRIGO LUIZ NEVES BARROS, WELLITON BARROS DE MAGALHÃES, LEONARDO OLIVEIRA MEDICI y CARLOS PIMENTEL. "COWPEA GROWTH AND YIELD IN SOLE CROP AND INTERCROPPED WITH MILLET". Revista Caatinga 30, n.º 1 (marzo de 2017): 53–58. http://dx.doi.org/10.1590/1983-21252017v30n106rc.
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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.
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SILVA, LANESSA VIEIRA DA, SILVIA BRAZ RODRIGUES DE OLIVEIRA, LEONARDO ARAÚJO DE AZEVEDO, ARTENISA CERQUEIRA RODRIGUES y AURENIVIA BONIFACIO. "COINOCULATION WITH Bradyrhizobium AND Trichoderma ALLEVIATES THE EFFECTS OF SALT STRESS IN COWPEA". Revista Caatinga 32, n.º 2 (junio de 2019): 336–44. http://dx.doi.org/10.1590/1983-21252019v32n206rc.
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ABSTRACT The deleterious effects of salt stress can be mitigated by the use of beneficial microorganisms. The aims of this study were to evaluate whether coinoculation with Bradyrhizobium and Trichoderma asperelloides alleviates salt stress in cowpea. The experiment was conducted in a greenhouse using pots filled with sterile soil. Seeds were sown and inoculated with Bradyrhizobium or coinoculated with Bradyrhizobium and T. asperelloides. At 15 days after sowing (DAS), the nitrogen-free nutritive solution was supplemented with 50 or 100 mmol L-1 sodium chloride (NaCl) to induce salinity. Uninoculated plants and irrigated with solution without NaCl were used as absolute control. At 35 DAS, plants were collected, and nodules were excised for use in the determinations. The absolute controls did not show root nodules. Salt stress decreased plant biomass and growth, especially in cowpea inoculated with Bradyrhizobium. The stem diameter increased in cowpea coinoculated with Bradyrhizobium and T. asperelloides, mainly in plants subjected to salt stress at 100 mmol L-1 NaCl. Cowpea coinoculated with Bradyrhizobium and T. asperelloides maintained a higher content of free ammonia and organic compounds in its nodules even under salt stress. We concluded that the coinoculation of cowpea with Bradyrhizobium and T. asperelloides induces an increase in the concentration of organic solutes in the root nodules, especially when cowpeas are cultivated under salinity. Therefore, the use of coinoculation with Bradyrhizobium and T. asperelloides alleviates the negative effects of salt stress in cowpea.
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OLASANTAN, F. O. "Effects of preceding maize (Zea mays) and cowpea (Vigna unguiculata) in sole cropping and intercropping on growth, yield and nitrogen requirement of okra (Abelmoschus esculentus)". Journal of Agricultural Science 131, n.º 3 (noviembre de 1998): 293–98. http://dx.doi.org/10.1017/s0021859698005711.
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Field experiments were conducted on Alfisols in Nigeria between 1991 and 1993 to determine the residual effect of maize (Zea mays) and cowpea (Vigna unguiculata) on the growth, pod yield and N response of a succeeding okra (Abelmoschus esculentus) crop. Cowpea and maize were grown alone with 30 and 60 kg/ha of N, P and K, respectively, or intercropped with 60 kg/ha as a basal dressing. The preceding crops had a significant effect on soil nutrient changes, okra growth and yield, and N response of okra. Cowpea increased the N, P and K status of the soil in both sole and mixed stands, compared with sole maize. Leaf area, pod weight and marketable pod yield of okra after sole cowpea or the maize/cowpea intercrop were all significantly higher than after sole maize. Although the application of nitrogen to succeeding okra promoted growth and increased pod yield, this was not accompanied by an increase in the pod yield of okra after sole cowpea or the maize/cowpea treatment beyond 45 kg N/ha. The beneficial effects of the preceding maize/cowpea intercrop on soil fertility, okra pod yield and amounts of N required for okra were partly due to the higher rate of basal nutrients applied as compared to the effects following sole cowpea.
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Jackai, L. E. N. y S. Oghiakhe. "Pod wall trichomes and resistance of two wild cowpea, Vigna vexillata, accessions to Maruca testualis (Geyer) (Lepidoptera: Pyralidae) and Clavigralla tomentosicollis Stål (Hemiptera: Coreidae)". Bulletin of Entomological Research 79, n.º 4 (noviembre de 1989): 595–605. http://dx.doi.org/10.1017/s0007485300018745.
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AbstractExperiments were conducted to investigate the role of pubescence in the resistance of two wild cowpea varieties, TVNu 72 and TVNu 73, to feeding and damage caused by two cowpea pests, Maruca testulalis (Geyer) and Clavigralla tomentosicollis Stål. The fine structure of the trichomes was also studied by electron microscopy in order to try to determine the role played by trichomes in the resistance of these varieties to both pests. Feeding and development were deterred in both insects on pods of TVNu 72 and TVNu 73 with or without trichomes compared to the susceptible variety, IT84E-124. In M. testulalis, the same effect was observed on seeds and flowers. However, M. testulalis larvae fed and developed better, as indicated by the higher growth index values, when trichomes were removed. Growth index estimates showed a 13-fold decrease when trichomes were left intact on both TVNu 72 and TVNu 73 compared to the cultivated susceptible control. It was concluded that resistance to M. testulalis was based on trichomes in the first instance (as a first line of defence) and phytochemicals. Survival of C. tomentosicollis nymphs was not affected by trichome removal even though adult feeding damage was slightly increased. This is explained in line with previous reports which indicate that phytochemicals may be the principal factor in the resistance of TVNu 72 and TVNu 73 to this species. Glandular and non-glandular trichomes were found to be present on both the cultivated and wild cowpea. Trichomes in the two types of cowpea differ significantly only in trichome number (susceptible cultivated cowpeas have more) and non-glandular trichome length (those on wild cowpea are ca 20 times longer). Trichome length and angle to pod surface seemed to be more important than density per se.
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Adigun, Joseph Aremu, Olusegun Raphael Adeyemi, Olumide Samuel Daramola y Patience Mojibade Olorunmaiye. "Response of cowpea (Vigna unguiculata, L., Walp) to inter-row spacing and weed competition". Agricultura Tropica et Subtropica 53, n.º 2 (1 de junio de 2020): 73–79. http://dx.doi.org/10.2478/ats-2020-0008.
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AbstractWeed infestation is one of the major factors attributed for the poor yield of cowpea in Nigeria and other parts of sub-Sahara Africa (SSA). Field trials were therefore conducted to evaluate the effect of row spacing and different weeding levels on weed control, growth and yield of cowpea during the early and late wet seasons of 2009. In both seasons, the use of 60 cm row spacing resulted in significant (P < 0.05) reduction in weed density by 18 – 39% and weed biomass by 17 – 27% with subsequent increase in cowpea growth and grain yield than 75 and 90 cm row spacing. Cowpea grain yield increased by 67 – 109% in the early season and 24 – 56% in the late season at 60 compared to 75 and 90 cm row spacing. Hoe weeding reduced weed growth significantly in both seasons with the lowest weed density and biomass recorded in plots weeded thrice. However, this was not significantly different from weed density and biomass recorded with two weedings in both seasons. Hoe weeding twice resulted in optimum growth and grain yield of cowpea. An additional weeding, however, did not improve cowpea growth and yield in both seasons. The results of this study showed that narrow (60 cm) inter-row spacing and two hoe weedings at 3 and 6 weeks after sowing (WAS) will improve weed control and productivity of cowpea. Additional weeding is considered superfluous.
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Boe, A., E. K. Twidwell y K. D. Rephart. "Growth and forage yield of cowpea and mungbean in the northern Great Plains". Canadian Journal of Plant Science 71, n.º 3 (1 de julio de 1991): 709–15. http://dx.doi.org/10.4141/cjps91-104.
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Cowpea [Vigna unguiculata (L.) Walp.] and mungbean [Vigna radiata (L.) Wilczek] are summer-annual legumes which have potential as forages in the northern Great Plains region of the USA during late summer when cool-season grass pastures decline in productivity. The objective of this study was to evaluate forage yield and growth response of these species when grown under different row spacings and planting rates. Victor cowpea and Berken mungbean were planted at 500 000 pure live seeds (PLS) ha−1 in row spacings of 25, 50, and 75 cm at two South Dakota locations in 1987. In 1988 the two species were planted at rates of either 250 000 or 500 000 PLS ha−1 in the same row spacings at three locations. Cowpea produced higher forage yields than mungbean at all locations in both years. Yields of both species decreased with increased row spacing. Species did not differ in plant weight, but plant number per unit of harvested area was greater for cowpea than mungbean. Forage yield was not significantly affected by planting rate at any location in 1988; however, plant weight, leaflets plant−1, and leaf area plant−1 were significantly greater for the low rate, showing that forage yield remained relatively constant across wide variations in plant population. Results indicate that both cowpea and mungbean have potential as summer annual forage crops. However, the consistently higher yield performance of the cowpea cultivar suggests that it was better adapted than the mungbean cultivar to the northern Great Plains region and consequently should be a better forage crop. Key words: Vigna unguiculata (L.) Walp., Vigna radiata (L.) Wilczek, yield, plant density, cowpea, mungbean
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Adewale Osipitan, O. "Weed Interference and Control in Cowpea Production: A Review". Journal of Agricultural Science 9, n.º 12 (15 de noviembre de 2017): 11. http://dx.doi.org/10.5539/jas.v9n12p11.
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In spite of the great economic potential of cowpea as both domestic and commercial crop, a number of constraints, which include insect pests, diseases and weeds, limits its production in West and many parts of Africa. Weeds reduced cowpea yield and value by competing for light, water and nutrients. Cowpea suffers from weeds particularly when the crop is in the early growth stages before ground cover. Yield losses cause by weeds alone in cowpea production can be as high as 76% depending on the cowpea cultivar, environment and weed management practices. A timely weed removal at the critical period, which falls within the first 40 days of cowpea growth, would help to prevent an unacceptable yield. Weed management in cowpea has been with low technology. Hand weeding is the most widely used weed control method in cowpea but they are usually expensive and labour intensive. Cultural practices such as narrow row spacing and planting of early maturing varieties are also used for weed control in cowpea. Herbicides, which are relatively easy to use and less expensive, have not been widely adopted for weed control in cowpea. There are limited number of selective herbicides with wide spectrum for weed control in cowpea. However, an integrated practices that involved pre-emergence weed control using herbicides or physical weeding, and a supplementary weed removal that would ensure weed control up to 40 days after cowpea emergence could substantially prevent yield losses associated with weed interference.
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Sebetha, E. T. y A. T. Modi. "Influence of Crop Growth Stages and Management Practices on Soil Water Content at Different Soil Depths under Dryland Conditions". Journal of Agricultural Science 9, n.º 11 (16 de octubre de 2017): 88. http://dx.doi.org/10.5539/jas.v9n11p88.
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Soil water loss through evaporation plays a role on low crop productivity and this is due to poor cropping systems and soil surface coverage. The study was carried out at three locations of North-West province of South Africa, which were Potchefstroom, Taung and Rustenburg during 2011/12 and 2012/13 planting seasons. The experimental design was a factorial experiment laid out in a randomised complete block design (RCBD) with three replicates. The experiment consisted of five cropping systems, which were monocropping cowpea, monocropping maize, cowpea followed by maize in rotation, maize followed by cowpea in rotation and intercropping maize-cowpea. The three crop growth stages compared in this study were before tasselling/flowering, during tasselling/pod formation and during physiological maturity of maize and cowpea. Soil was sampled for the 0-0.15, 0.15-0.3, 0.3-0.6 and 0.6-0.9 m depth increments and soil water content determined using the Gravimetric method. The crop growth stage before tasselling/flowering in maize/cowpea had significantly (P < 0.05) higher water content of 10.2, 10.8, 12.5 and 13.3% at the depth of 0-0.15, 0.15-0.3, 0.3-0.6 and 0.6-0.9 m respectively. Soil collected at Rustenburg and Potchefstroom had significantly (P < 0.05) higher water content of 13.5 and 10.2; 15.9 and 10.9; 18.3 and 12.8; 18.4 and 14.5% at the depths of 0-0.15, 0.15-0.3, 0.3-0.6 and 0.6-0.9 m respectively. Monocropping cowpea plots had significantly (P < 0.05) higher water content of 12.4% than other cropping systems at the soil depth of 0.3-0.6 m. Monocropping plots of cowpea had the ability to hold soil water and this depends on the type of cowpea cultivar and canopy cover. The stage before tasselling/flowering of maize-cowpea (V10/Vn) was found to have high soil water content. Soil water content differs across locations due to different soil physical properties.
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Wang, Guangyao, Mathieu Ngouajio, Milton E. McGiffen y Chad M. Hutchinson. "Summer Cover Crop and In-season Management System Affect Growth and Yield of Lettuce and Cantaloupe". HortScience 43, n.º 5 (agosto de 2008): 1398–403. http://dx.doi.org/10.21273/hortsci.43.5.1398.
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The effect of summer cover crop and management system on subsequent fall romaine lettuce (Lactuca sativa L.) and spring muskmelon (Cucumis melo L.) growth and yield was evaluated in the Coachella Valley of California from 1999 to 2003. Cover crop treatments included: 1) cowpea [Vigna unguiculata (L.) Walp.] incorporated into the soil in the fall (CPI), 2) cowpea used as mulch in the fall (CPM), 3) sudangrass [Sorghum bicolor (L) Moench] incorporated into the soil in the fall (SGI), and 4) a bare ground control (BG). Management system treatments included: 1) conventional system (CON), 2) integrated crop management (ICM), and 3) organic system (ORG). Cowpea cover crop, either incorporated or used as surface mulch, increased lettuce growth and yield by increasing biomass allocation to lettuce leaf and leaf area growth. Cowpea mulch decreased muskmelon leaf and biomass growth and reduced muskmelon yield. Sudangrass produced more biomass than cowpea and reduced lettuce growth and yield. However, in the following spring, the SGI treatment had the highest muskmelon yield. Lettuce growth was significantly affected by management system, while muskmelon growth at the early stage was unaffected. The organic system reduced both lettuce and muskmelon yield compared with CON and ICM management systems.
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Wilson, Clyde, Xuan Liu, Scott M. Lesch y Donald L. Suarez. "Growth response of major USA cowpea cultivars". Plant Science 170, n.º 6 (junio de 2006): 1095–101. http://dx.doi.org/10.1016/j.plantsci.2006.01.010.
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Barbosa, Inácio J., Henderson C. Sousa, Fernanda Schneider, Geocleber G. de Sousa, Carla I. N. Lessa y Lamine Sanó. "Mulch with sugarcane bagasse and bamboo straw attenuates salt stress in cowpea cultivation". Revista Brasileira de Engenharia Agrícola e Ambiental 25, n.º 7 (julio de 2021): 485–91. http://dx.doi.org/10.1590/1807-1929/agriambi.v25n7p485-491.
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HIGHLIGHTS Saline stress did not affect the initial growth of the cowpea crop. The use of mulch provides better morphological results in the cowpea crop. Vegetal mulches as soil protection (sugarcane bagasse and bamboo straw) attenuated effect of salts on gas exchange of cowpea.
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Booker, H. M., P. Umaharan y C. R. McDavid. "Effect of Cowpea severe mosaic virus on Crop Growth Characteristics and Yield of Cowpea". Plant Disease 89, n.º 5 (mayo de 2005): 515–20. http://dx.doi.org/10.1094/pd-89-0515.
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Field experiments were carried out in St. Augustine, Trinidad & Tobago, West Indies to determine the effects of time of inoculation of Cowpea severe mosaic virus (CPSMV) and cultivar on crop growth and yield in cowpea (Vigna unguiculata). Crop growth and yield loss were investigated through growth analysis and yield component analysis on three cultivars in two seasons (wet and dry). Time of inoculation had the most profound impact on yield. Inoculations during the early log phase (seedling stage), 12 days after seeding (DAS), consistently had the greatest impact (50 to 85% yield loss) compared with those inoculated during the exponential growth phase (24 DAS; 22 to 66% yield loss) or linear growth phase (35 DAS; 2 to 36% yield loss). The effects were particularly pronounced in the dry season and in the more determinate cultivar, H8-8-27. Reduction in maximum leaf area index, leaf area duration, or maximum vegetative dry matter explained reductions in yield. Yield reductions resulted primarily from reduced pod number per plant and, to a lesser extent, from reduced average pod dry weight. The results show that CPSMV control measures should be aimed at delaying infection by CPSMV to minimize the impact on cowpea yield.
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Kandel, Tanka P., Prasanna H. Gowda, Brian K. Northup y Alexandre C. Rocateli. "Winter wheat yield and nitrous oxide emissions in response to cowpea-based green manure and nitrogen fertilization". Experimental Agriculture 56, n.º 2 (11 de octubre de 2019): 239–54. http://dx.doi.org/10.1017/s0014479719000334.
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AbstractThe aim of this study was to compare the effects of cowpea green manure and inorganic nitrogen (N) fertilizers on yields of winter wheat and soil emissions of nitrous oxide (N2O). The comparisons included cowpea grown solely as green manure where all biomass was terminated at maturity by tillage, summer fallow treatments with 90 kg N ha−1 as urea (90-N), and no fertilization (control) at planting of winter wheat. Fluxes of N2O were measured by closed chamber methods after soil incorporation of cowpea in autumn (October–November) and harvesting of winter wheat in summer (June–August). Growth and yields of winter wheat and N concentrations in grain and straw were also measured. Cowpea produced 9.5 Mg ha−1 shoot biomass with 253 kg N ha−1 at termination. Although soil moisture was favorable for denitrification after soil incorporation of cowpea biomass, low concentrations of soil mineral N restricted emissions of N2O from cowpea treatment. However, increased concentrations of soil mineral N and large rainfall-induced emissions were recorded from the cowpea treatment during summer. Growth of winter wheat, yield, and grain N concentrations were lowest in response to cowpea treatment and highest in 90-N treatment. In conclusion, late terminated cowpea may reduce yield of winter wheat and increase emissions of N2O outside of wheat growing seasons due to poor synchronization of N mineralization from cowpea biomass with N-demand of winter wheat.
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Eduardo Melo Santiago, Franklin, Flávia Louzeiro de Aguiar Santiago, José Ferreira Lustosa Filho y Rafael Felippe Ratke. "Plant growth and symptomatology of macronutrient deficiencies in cowpea plants". Comunicata Scientiae 9, n.º 3 (4 de noviembre de 2018): 503–8. http://dx.doi.org/10.14295/cs.v9i3.2593.
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Cowpea is a widely grown annual legume in the North and Northeast regions of Brazil. It is one of the main sources of protein and income for the populations of these regions. However, few studies have shown the nutritional requirements, and symptomatology of nutritional deficiencies of cowpea cultivars. In this context, the objective of this work was to evaluate the initial growth and symptomatology of macronutrient deficiencies in cowpea plants of the BR17-Gurguéia cultivar. A randomized complete experimental design with three replications was used, with seven treatments consisted of nutrient solutions containing no N, P, K, Ca, Mg, or S, and a nutrient solution containing all macro and micronutrients as control, using one plant per plot. Plant height, stem diameter, number of leaves, leaf area, root volume, and shoot and root dry weights were evaluated, and visual symptoms of nutritional deficiencies were described at 30 days after planting. Nitrogen, phosphorus, potassium, calcium, and magnesium were the most limiting nutrients for the vegetative growth and biomass production of cowpea up to 30 days of cultivation. The absence of these elements in the nutrient solution caused morphological changes and visual symptoms that are characteristic of the nutritional deficiency of these nutrients.
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Stoilova, Tsvetelina y Malgozhata Berova. "Differences in growth and productivity between genotypes of common bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata L.) in the Sadovo region of Bulgaria". Folia Horticulturae 24, n.º 1 (1 de enero de 2012): 53–59. http://dx.doi.org/10.2478/v10245-012-0006-0.
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Differences in growth and productivity between genotypes of common bean (Phaseolus vulgarisL.) and cowpea (Vigna unguiculataL.) in the Sadovo region of BulgariaThe study examined the differences between 10 accessions of common bean and cowpea during the vegetation period. Different stages of development and elements of yield were analysed in the climatic conditions of Sadovo (Bulgaria), which is characterised by hot summers and insufficient rainfalls. All genotypes were planted in the second 10 days of April. They emerged 10-15 days after sowing. The flowering stage occurred after 28-34 days in common bean and 45-60 days in cowpea. The vegetation period duration was much longer in cowpea (over 98 days) than in the common bean (less then 80 days). The reproductive organs (number of pods and seeds per plant, size of pods and seeds, weight of pods and seeds per plant) were quite different for the two crops. The mean number of pods per plant was 8.84 in common beans and 13.22 for cowpea; the number of seeds per pod was 4.05 for beans 10.56 for cowpea; the number of seeds per plant was 25.65 for beans and 93.47 for cowpea. The bean seeds were larger than the cowpea seeds, with 100-seed weights of 41.86 g and 15.73 g, respectively. Under the climatic conditions of Sadovo, the cowpea accessions showed a more stable yield, resulting in more pods and seeds per plant and weight of seeds per plant, when compared with common bean accessions.
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Hawkins, C. D. B., M. I. Whitecross y M. J. Aston. "Long-term effects on cowpea plant growth of a short-term cowpea aphid infestation". Canadian Journal of Botany 64, n.º 8 (1 de agosto de 1986): 1727–32. http://dx.doi.org/10.1139/b86-231.
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Two-week-old cowpea seedlings (Vigna unguiculata (L.) Walp.) were infested with cowpea aphids (Aphis craccivora Koch (Homoptera: Aphididae)) for 5, 10, 15, and 20 days at which time the aphids were removed with a systemic insecticide. The seedlings were then allowed to grow for another 3 months. By day 10, plant dry weights, mean relative growth rates [Formula: see text], and mean unit leaf rates (Ē) were all significantly reduced in the infested plants, and these relationships still held at day 20. Apparent decreases in photosynthesis and (or) increases in respiration were the primary causes of these reductions. There were no significant differences between control and experimental treatments for [Formula: see text] calculated from day 0, and total number of seeds and seed pods produced at the end of the study. Control plants had significantly more mature seed pods and seeds, while formerly infested plants had significantly more mature and unripe seeds per pod, more unripe seed pods and seeds produced, and greater values for [Formula: see text] from the time of aphid removal until the end of the experiment. This latter increase in [Formula: see text] indicates a form of compensatory growth. It is proposed that the compensatory growth of previously infested plants and ultimate similarity in seed production, as compared with control plants, may have resulted from aphid-induced changes via nonhormonal compounds acting as phytohormone regulators. The different durations of aphid infestation used had no detectable effect on long-term growth.
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Santos, Joseany Andrade, Luís Alfredo Pinheiro Leal Nunes, Wanderley José de Melo, Marcia Barreto do Vale Figueiredo, Rajeev Pratap Singh, Antônio Aécio Carvalho Bezerra y Ademir Sérgio Ferreira de Araújo. "Growth, nodulation and nitrogen fixation of cowpea in soils amended with composted tannery sludge". Revista Brasileira de Ciência do Solo 35, n.º 6 (diciembre de 2011): 1865–71. http://dx.doi.org/10.1590/s0100-06832011000600003.
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Tannery wastes generation is increasing every year and a suitable method for tannery sludge management is necessary in order to decrease this environmental problem. The composting is recognized as a suitable method for sludge recycling.. The effect of tannery sludge compost (TSC) rates on growth, nodulation and N fixation of cowpea was investigated. Sandy and clayey soils were amended with TSC at rates of 0, 7.5, 15, 30, and 60 t ha-1. The shoot dry weight of cowpea plants 45 days after emergence (DAE) was greater in the TSC-amended than in the unamended soil. In the sandy soil, nodule dry weight increased with TSC application 45 DAE. In the clayey soil, 45 DAE, nodule dry weight decreased with TSC amendment levels greater than 7.5 t ha-1 compared to the unamended control. The application of TSC increased N accumulation in the cowpea plants. The results suggest that cowpea responds differently to TSC depending on the amendment rate and initial soil type.
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Nevhulaudzi, Thalukanyo, Khayalethu Ntushelo y Sheku Alfred Kanu. "Growth and Nutritional Responses of Cowpea (cv. Soronko) to Short-term Elevated Temperature". HortScience 55, n.º 9 (septiembre de 2020): 1495–99. http://dx.doi.org/10.21273/hortsci15132-20.
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Short-term variations in temperature associated with climate change have been noted to affect the physiological processes and metabolite profile of plants, including the nutritional status, ultimately affecting their growth and development. An evaluation of the effects of elevated temperatures on the growth and nutritional quality of cowpea was performed during this experiment. The main objective was to evaluate the effects of short-term elevated temperatures on the nutritional quality of cowpea at different growth stages. Surface-sterilized seeds of cowpea (cv. Soronko) were germinated in pots in the glasshouse. At different growth stages (preflowering, flowering, and postflowering), plants were incubated in growth chambers set at three different temperature regimes (25, 30, and 35 °C) for a period of 7 days. Compared with control (25 °C), exposure to both elevated temperatures (30 and 35 °C) reduced the whole plant fresh weight and dry weight by 30% and 52% and 42% and 29%, respectively, at the preflowering stage, and by 31 and 60% and 47 and 63%, respectively, at the flowering/anthesis stage. However, no significant difference in whole plant biomass was noted between elevated temperatures (35%) and the control temperature at the postflowering stage. Short-term exposure to an elevated temperature (35 °C) increased the shoot crude protein content (5.59 N%) of cowpea compared with control (3.77 N%) and preflowering stage. In contrast, at the flowering stage, an elevated temperature (35 °C) reduced the crude protein content (1.77%) of the shoot compared with control (5.59%). At an elevated temperature (35 °C), the preflowering and flowering stages of cowpea were most affected compared with control. These results suggest that the preflowering and flowering stages of cowpea compared with the postflowering stage are more susceptible to elevated temperatures (30 to 35 °C).
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Alghali, Aliyageen M. "Efficacy of insecticidal applications based on calendar intervals and plant growth stages for control of insect pests on cowpea". Insect Science and Its Application 16, n.º 1 (marzo de 1995): 109–12. http://dx.doi.org/10.1017/s1742758400018397.
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AbstractStudies were carried out to compare the efficacy of insecticide schedules based on calendar intervals with those based on plant growth stages for the control of cowpea insect pests. Spray schedules based on calendar intervals and plant growth stage gave reasonable control of the pest complex and increased grain yields significantly. However, spray schedules based on plant growth stages alone were more efficient for two of the three cowpea varieties tested. This was attributed to differences in maturity periods which made spraying by regular calendar intervals slightly out of phase with attack by key insect pests. Thus, spray schedules based on plant growth stages are recommended for the control of insect pests of cowpea.
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Baerg, Roger J. y Michael Barrett. "The Basis of Imazethapyr Tolerance in Cowpea (Vigna sinensis)". Weed Science 44, n.º 4 (diciembre de 1996): 769–75. http://dx.doi.org/10.1017/s0043174500094698.
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Greenhouse and laboratory experiments were conducted to determine the basis of imazethapyr tolerance in cowpea. Cowpea required more than 700 g ha−1imazethapyr to reduce shoot growth 50% while corn required 70 g ha−1to reduce growth 50% in greenhouse experiments. Extractable acetohydroxy acid synthase activity from cowpea 24 h after foliar imazethapyr treatment was only 20% of that of untreated cowpea but increased to control levels 72 h after treatment (HAT). The unifoliate leaves of cowpea absorbed 25% of the14C-imazethapyr applied 72 HAT. Movement of14C-imazethapyr out of the treated zone increased gradually to approximately 47% of the absorbed14C 168 HAT. Parent imazethapyr decreased from 41 to 27% of the recovered14C between 4 and 24 HAT, and continued to decrease to 14% by 168 HAT. Polar metabolites increased from 27 to 55% of the recovered14C from 24 to 168 HAT. The polar metabolites of imazethapyr included hydroxyimazethapyr and conjugates of hydroxyimazethapyr. Tolerance of cowpea to imazethapyr is based on the plants ability to metabolize the herbicide to nontoxic metabolites.
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Hulugalle, NR y P. Entwistle. "Effects of sowing cowpea on properties of an irrigated Vertisol and growth and yield of succeeding cotton". Soil Research 34, n.º 4 (1996): 529. http://dx.doi.org/10.1071/sr9960529.
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The effects of sowing a break crop of cowpea on soil properties, nutrient uptake, growth, and yield of furrow-irrigated cotton were evaluated in a trial conducted from 1993 to 1995 in a Typic Haplustert (Vertisol) with high subsoil compaction in north-western New South Wales, Australia. The experimental treatments were cowpea (Vigna unguiculata Walp.)-cotton (Gossypium hirsutum L.), continuous cotton, and long-fallow cotton (cotton alternating annually with a bare fallow). Cotton was sown in all plots in 1994 with minimum tillage. Soil was sampled to a depth of 0.6 m in August 1993, May–June 1994, and April 1995. Soil properties evaluated were organic matter fractions, resilience (a measure of the self-mulching ability of the soil), plastic limit, strength (as cone resistance), shrinkage indices derived from shrinkage curves, exchangeable Ca, Mg, K, and Na, pH, nitrate-N, and electrical conductivity. Profile water content and water extraction, nutrient uptake, crop vegetative growth, cotton lint yield, and fibre quality were also quantified. Compared with fallowing, sowing either cotton or cowpea in 1993 decreased pH and aggregate size formed after puddling and drying, and increased soil organic matter and plastic limit. Cropping also increased exchangeable cations in the surface 0.3 m of the soil. Nitrate-N in the 0–0.15 m depth was 23% higher after cowpea than after fallow. Amelioration of soil compaction was quickest in the short-term where continuous cotton was sown, but was also observed with time in plots where cowpea was sown in 1993. In comparison with cowpea-cotton and long-fallow cotton, continuous cotton had the highest nutrient uptake. Growth of cotton sown after either fallow or cotton was greater than that of cotton sown after cowpea, with lint yield being highest in the previously fallowed plots. Lint fibre quality did not differ significantly between treatments. Overall, the benefits of sowing cowpea in terms of improvements in soil properties and crop yields were either small or negligible in comparison with fallowing or sowing cotton.
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Adigun, Joseph, A. O. Osipitan, Segun Toyosi Lagoke, Raphael Olusegun Adeyemi y Stephen Olaoluwa Afolami. "Growth and Yield Performance of Cowpea (Vigna Unguiculata (L.) Walp) as influenced by Row-Spacing and Period of Weed interference in South-West Nigeria". Journal of Agricultural Science 6, n.º 4 (15 de marzo de 2014): 188. http://dx.doi.org/10.5539/jas.v6n4p188.
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Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.
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Islam, Md Mozahidul, Md Sabibul Haque y AKM Golam Sarwar. "Salt tolerance of cowpea genotypes during seed germination and seedling growth". Journal of the Bangladesh Agricultural University 17, n.º 1 (28 de marzo de 2019): 39–44. http://dx.doi.org/10.3329/jbau.v17i1.40661.
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Cowpea (Vigna unguiculata (L.) Walp.) is one of the most important grain legumes worldwide and its production is affected by increasing soil salinity due to global climate change. An experiment was conducted at the Plant Physiology Laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh to evaluate the germination capability of seven cowpea genotypes under salt stress. The germination test was carried out in Petri dishes following two factorial CRD with three replications. Seven cowpea genotypes viz, Red Pine, Green Super, Hai Jiang San Hao, Kegornatki, Kegornatki Green, Kegornatki HYV & Kegornatki Red; and three salt levels viz, 0, 6 & 12 dSm-1, were used as experimental treatments. The germination percentage (GP), mean germination time (MGT), radicle and plumule length, radicle and plumule fresh and dry weight and different stress tolerance indices were recorded to screen the genotypes for salt tolerance. The study highlighted that salt concentrations drastically reduced seed germination and significantly delayed the process in all genotypes. The GP, length and biomass of radicle and plumule and salt tolerance indices were significantly decreased while the MGT was significantly increased with increasing salt stress in all cowpea genotypes. A significant variation among the genotypes in response to salt stress was also observed. Among the seven cowpea genotypes, Hai Jiang San Hao and Green Super showed higher salt tolerance in comparison to the other genotypes based on the measured traits; these genotypes can be used for further breeding program and/or cultivation in coastal saline prone areas with further investigation.
J. Bangladesh Agril. Univ. 17(1): 39–44, March 2019
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Bell, RW, DG Edwards y CJ Asher. "External calcium requirements for growth and nodulation of six tropical food legumes grown in flowing culture solution". Australian Journal of Agricultural Research 40, n.º 1 (1989): 85. http://dx.doi.org/10.1071/ar9890085.
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Six tropical food legumes, peanut cv. Red Spanish, pigeonpea cv. Royes, guar cv. Brooks, soybean cv. Fitzroy, and cowpea cv. Vita 4 and CPI 282 15, were grown for 20 days at six constant solution calcium concentrations (2, 12, 50, 100, 500 and 2500 8M ) in flowing solution culture with adequate inorganic nitrogen (500 8M NO3 and with controlled nutrient concentrations. Bradyrhizobium CB756 was added at a rate of approximately 105 cells/ml of nutrient solution. Growth of all genotypes except guar was satisfactory at >12 8M calcium, with 75-100% of maximum root and shoot yield being obtained. Solution calcium concentrations required for maximum top growth were 12 8M for cowpea CPI 28215, 50 8M for peanut, 100 8M for soybean, and 2500 8M for cowpea cv. Vita 4, guar and pigeonpea. Root growth responded to solution calcium concentrations in the same way as top growth, except for cowpea cv. Vita 4 and pigeonpea, which both produced maximum root dry matter at 12 8M calcium. External calcium requirements for unrestricted growth may have been overestimated in guar because phosphorus deficiency appeared to limit growth at <500 8M calcium. Effects of suboptimal calcium concentrations included prevention of nodulation, delays in nodule appearance and a reduction in both nodule numbers and the proportion of plants which nodulated. Guar and pigeonpea formed nodules only at a 50 8M calcium, whereas cowpea and peanut formed nodules at 2 8M calcium. Maximum nodule numbers were recorded at lower (peanut), higher (cowpea cv. Vita 4, CPI 28215 and pigeonpea) or the same (guar) solution calcium concentration as that required for maximum root growth. Nodule formation in peanut was satisfactory at solution calcium concentrations as low as 12 8M. The results are discussed in relation to reports on the adaptation of these legumes to highly weathered soils low in calcium.
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J.K., Sinchana y Sheeja K. Raj. "A review on integrated approach for the management of weeds in Cowpea (Vigna unguiculata)". Journal of Applied and Natural Science 12, n.º 4 (24 de noviembre de 2020): 504–10. http://dx.doi.org/10.31018/jans.v12i4.2386.
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Cowpea (Vigna unguiculata) is the most important leguminous crop raised as pulse as well as a vegetable crop in India. The slow initial growth and wider spacing necessitate weed control in the early stages of crop growth. The critical period of crop weed competition in cowpea was 20 to 30 DAS. Season-long crop weed competition resulted in a yield reduction of 40 to 90 per cent in cowpea depending on the intensity of weed infestation, weed flora, season, location, and the climatic condition prevailed. Mulching, manual weeding and stale seedbed are the different cultural methods which can be adopted for weed control in cowpea. Chemical method of weed control is the cheapest and economically viable option for weed control in cowpea. Both Pre-emergence herbicides viz., pendimethalin, diclosulam and imazethapyr and post-emergence herbicides viz., imazethapyr, quizalofop-p-ethyl can be used for weed control in cowpea. Studies revealed that pre-emergence application of herbicide (imazethapyr/pendimethalin or diclosulam) followed by manual weeding or post-emergence application of herbicides (quizalofop-p-ethyl or imazethapyr) or mulching followed by post-emergence application of herbicides (quizalofop-p-ethyl or imazethapyr) were found to be more effective for the broad-spectrum weed control in cowpea. The integrated approach of weed control has resulted in a higher yield, net returns and B: C ratio in cowpea.
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Olabiyi, Timothy I. y Oladiran J. Ojo. "Impact Assessment of Neem Compost and Trichoderma harzianum Solution in the Control of Root Knot Nematode Disease on Cowpea". International Journal of Phytopathology 5, n.º 2 (31 de agosto de 2016): 67–71. http://dx.doi.org/10.33687/phytopath.005.02.1475.
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Efficacy of neem leaf based compost andTrichoderma harzianum solution were assessed on root knot nematode pest of two cowpea varieties at the screen house of the International Institute of Tropical Agriculture (IITA), Ibadan during 2012 planting season. The two cowpea varieties which have been confirmed to be susceptible to root knot nematode, IT96D-610 and IT84S-2246-4 were the test crops. The experimental pots (10kg soil) were inoculated with 5,000 root knot nematode eggs. The treatments were neem compost and T. harzianum solution with application rates of 2 ton/ha and 1x10-7 spores respectively. The pots that were not treated served as the control. Each treatment was replicated 4 times while the statistical design was complete randomized design. Data were collected on the growth and yield of cowpea, and also on the nematode populations in the soil and cowpea root. The results indicated that neem compost and T. harzianum solution significantly increased the growth and yield of IT96D-610 and IT84S-2246-4 cowpea varieties grown in the root knot nematode inoculated soil. The populations of root knot nematode in the soil and cowpea root were significantly reduced. The level of root damage (root gall) was significantly reduced in the neem compost and T. harzianum treated cowpea when compared with the untreated control.
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Fening, J. O., W. Dogbe y S. K. A. Danso. "Assessment of the potential to improve N fixation by cowpea(Vigna unguiculata (L.) Walp.) in Ghanaian soils". American Journal of Alternative Agriculture 16, n.º 2 (junio de 2001): 57–65. http://dx.doi.org/10.1017/s0889189300008924.
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AbstractThe potential to improve N fixation by cowpea in Ghanaian soils was examined through: (1) assessment of the natural nodulation of 45 cowpea cultivars in 20 soils sampled from 5 ecological zones; (2) determination of the numbers of cowpea bradyrhizobial isolates in the soils; and (3) determination of the response of cowpea to N fertilization. The ability of 45 cowpea cultivars to nodulate naturally in the various soils showed wide cultural adaptability. Counts of indigenous bradyrhizobia showed that most soils in Ghana contained large populations capable of nodulating cowpea. These ranged from 0.6 × 10 bradyrhizobia cells g soil−1to 3.1 × 104cells g soil−1, with 60% of the soils containing more than 103cells g soil−1. Response of cowpea to N fertilization differed according to soil type. In general all cowpea cultivars showed significant response to increasing N fertilizer applications, indicating that N fixation was not providing the plants with sufficient N for maximum growth and yield. This study suggests that inoculation of cowpea with effective indigenous strains of bradyrhizobial species has considerable potential to improve this situation.
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Worku, Mulumebet, Sarah Adjei-Fremah, Niki Whitley y Louis Jackai. "Effect of Cowpea (Vigna unguiculata) Pasture Grazing on Growth, Gastrointestinal Parasite Infection and Immune Response Biomarkers of Goat". Journal of Agricultural Science 10, n.º 1 (13 de diciembre de 2017): 27. http://dx.doi.org/10.5539/jas.v10n1p27.
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The objective of this study was to evaluate the effect of grazing cowpea pastures on growth, parasite egg count and biomarkers of immune response in goats. Spanish and Savannah goats (n = 48) stratified by initial body weight (42.0±7.0 kg) and fecal egg count (FEC), were randomly assigned to three pasture forages (Cowpea varieties: Mississippi silver (MS), or Iron and Clay (IC) or Pearl millet (PM) as control with 4 replicates, for a 28-day feeding trial. Forage samples collected at the start of the study were analyzed for nutrients, chemical and polyphenols content. Body weight, body condition score, and fecal egg count were measured weekly. Blood was collected from goats on days 0 and 28 for PCV and white blood cell differential counts. The concentration of total proteins, prostaglandin E2 (PGE2) and total antioxidant capacity (TAC) were evaluated in blood serum. Concentration of DNA isolated from fecal samples was used as a measure of gut health. Goats grazed on cowpea forage (MS and IC) had higher body weight (p = 0.01) compared to goats grazed on PM. Percent lymphocyte (p = 0.008) and neutrophil (p = 0.013) increased in MS fed goats. Goats grazed on MS pasture had decreased FEC (p = 0.03) also. Cowpea pasture grazing had no effect on serum protein concentration, PCV and BCS (p > 0.05), but decreased PGE2 concentration in serum. The concentration of TAC in serum, increased at day 28 (p < 0.05). The concentration of fecal microbial DNA decreased in all the treatment groups at day 28. Cowpea forage grazing had an impact on body weight, FEC, and blood serum parameters (PGE2, TAC) in goats. These results demonstrate that freshly grazed cowpea forage has potential impact and benefits on growth and health of goats. Integrating cowpea diet in goat feeding system may enhance growth performance, stimulate and prime the immune system for defense against gastrointestinal parasites.
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Blache, D., DW Miller, JTB Milton y GB Martin. "The secretion of gonadotrophins, insulin and insulin-like growth factor 1 by Merino rams supplemented with different legume seeds". Australian Journal of Agricultural Research 47, n.º 6 (1996): 843. http://dx.doi.org/10.1071/ar9960843.
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Supplementing mature rams with lupin seed (Lupinus angustifolius, a highly digestible source of energy and protein) increases gonadotrophin secretion within 5-10 days. When sheep receive a post-ruminal supplement of protein and energy equivalent to that in the lupin supplement, LH secretion is increased but not to the same extent as with lupin seed itself. This suggests that lupin seed contains a specific mixture of nutrients or an unknown component that exerts effects on the brain centres that control gonadotrophin secretion. This hypothesis was tested by comparing the responses to isonitrogenous and isoenergetic supplements of 3 legumes: lupins, cowpeas, and soybeans. Rams were fed the supplements for 10 days and blood was sampled every 20 min for 24 h on days -1, 5, and 10 relative to the start of supplementation. The plasma was assayed for LH, FSH, and the metabolic hormones insulin and insulin-like growth factor 1 (IGF-1). Both the cowpea and the lupin supplements increased LH pulse frequency and the mean concentrations of insulin and IGF-1 on days 5 and 10 compared with day -1 (P < 0.05). The soybean supplement did not affect LH pulse frequency or the concentrations of insulin or IGF-1. Only the cowpea supplement increased the mean concentration of FSH. The nutritional stimulation of the reproductive centres of the brain appears not to be specific to lupins, because the diet supplemented with cowpeas evoked similar responses. The lack of response to soybean seed suggests that the effects of diet on secretion of metabolic and gonadotrophic hormones are not due simply to the total energy and protein content of the diets, but to subtle differences in their chemical constituents.
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Ahmad, M. H. y V. Morgan. "Characterization of a cowpea (Vigna unguiculata) rhizobiophage and its effect on cowpea nodulation and growth". Biology and Fertility of Soils 18, n.º 4 (1994): 297–301. http://dx.doi.org/10.1007/bf00570632.
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Kapravelou, Garyfallia, Rosario Martínez, Jole Martino, Jesus M. Porres y Ignacio Fernández-Fígares. "Natural Fermentation of Cowpea (Vigna unguiculata) Flour Improves the Nutritive Utilization of Indispensable Amino Acids and Phosphorus by Growing Rats". Nutrients 12, n.º 8 (23 de julio de 2020): 2186. http://dx.doi.org/10.3390/nu12082186.
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Cowpea (Vigna unguiculata) is among the most cultivated legumes, with interesting agronomic and environmental properties, and great potential as a nutritious food. The nutritional value of cowpea can be improved by technological processing. In this study, we showed that natural fermentation improved bioavailability of protein, amino acids, and dietary essential minerals from cowpea in growing rats, thus strengthening its potential value as functional food or food supplement. Forty Wistar albino rats (48 ± 1.8 g), were fed one of four experimental diets (n = 10 rats per diet): casein, raw cowpea, fermented cowpea or fermented and autoclaved cowpea. Despite lower growth indices of raw and fermented cowpea protein (PER, FTI) than casein, fermentation enhanced apparent digestibility of arginine, leucine, lysine, methionine, phenylalanine, tyrosine, and valine, and true digestibility of essential amino acids, except for tyrosine and valine, compared to raw cowpea. On the other hand, autoclaving of fermented cowpea flour decreased apparent, as did true digestibility of sulfur amino acids. Regarding the nutritive utilization of dietary essential minerals, Vigna unguiculata was a good source of available P, Mg, and K, while fermentation significantly improved the availability of P. Overall, cowpea was a good source of digestible essential amino acids and minerals and fermentation significantly improved its nutritional value that was not further enhanced by autoclaving.
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SURESH, G. y J. V. RAO. "THE INFLUENCE OF NITROGEN-FIXING TREES AND FERTILIZER NITROGEN LEVELS ON THE GROWTH, YIELD AND NITROGEN UPTAKE OF COWPEA ON A RAINFED ALFISOL". Experimental Agriculture 36, n.º 1 (enero de 2000): 41–50. http://dx.doi.org/10.1017/s001447970036104x.
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A field experiment was conducted to study the influence of 8- to 9-year-old nitrogen-fixing tree species (Faidherbia albida, Acacia ferruginea, Albizia lebbeck) and fertilizer nitrogen levels on yield and nitrogen uptake of intercropped cowpea (Vigna unguiculata). Grain and dry fodder yields of cowpea were reduced by 9% to 27% and by 11% to 35% respectively compared with the sole crop. Application of fertilizer nitrogen produced significantly higher yields. Nitrogen uptakes by leaves, stems and grain of cowpea were significantly reduced under A. ferruginea and A. lebbeck, but cowpea as sole crop and under F. albida showed no differences. Nitrogen uptake in different plant parts increased with increase in fertilizer nitrogen level.
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Sá, Francisco Vanies da Silva, Miguel Ferreira Neto, Yuri Bezerra de Lima, Emanoela Pereira de Paiva, Rômulo Costa Prata, Claudivan Feitosa Lacerda y Marcos Eric Baborsa Brito. "Growth, gas exchange and photochemical efficiency of the cowpea bean under salt stress and phosphorus fertilization". Comunicata Scientiae 9, n.º 4 (4 de enero de 2019): 668–79. http://dx.doi.org/10.14295/cs.v9i4.2763.
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Cowpea is widely cultivated in semiarid regions; however, these regions face serious problems with salinity of water and soil, thus constituting an abiotic stress that limits the development of this species. The objective of this study was to study the influence of phosphate fertilization on the morphophysiological components of cowpea plants irrigated with salinized water during the vegetative and reproductive phase. The research was carried out in a greenhouse from September to December 2015. A randomized complete block design with treatments arranged in a 5 x 3 factorial scheme with five replications was used. The factors consisted of the use of five levels of electrical conductivity of irrigation water: 0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1 and three doses of phosphorus corresponding to 60%, 100% and 140% of the dose recommended for the culture that was 60 kg ha-1. The plants of cowpea cv. Paulistinha were cultivated in lysimeters with a capacity of 8 dm3. At 30 and 49 days after sowing, periods corresponding to the vegetative (V4) and reproductive (V8 / R1) phases of the culture were evaluated gas exchange, chlorophyll fluorescence and growth. The increase in the electrical conductivity of the water reduced the growth, the photochemical activity and the phytomass accumulation of the cowpea plants, independent of the phenological phase. The higher dose of simple superphosphate increased the growth and photosynthetic activity of cowpea, mainly in the reproductive phase; Independent of the salinity of irrigation water.
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Ojo, V. O. A., S. J. Olufemi, G. A. Adetokunbo, B. T. Odunaye, B. A. Bakare y T. A. Adeyemi. "Growth components and chemical composition of some improved dual-purpose cowpea (Vigna unguiculata L. Walp) varieties as influenced by manure application". Nigerian Journal of Animal Production 44, n.º 2 (26 de diciembre de 2020): 299–310. http://dx.doi.org/10.51791/njap.v44i2.1122.
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Field experiment was conducted to determine the effect of swine manure application on the growth components and chemical composition of nine varieties of improved dual-purpose cowpea (Vigna unguiculata L. Walp). The experiment was laid out as a 2 x 9 factorial design with two levels of manure application (0kg ha-1 and 5kg ha-1) and nine varieties of improved dual-purpose cowpea at three replicates. Agronomy parameters and dry matter yield of the cowpea were determined six weeks after sowing. Results showed that unfertilized variety IT- 332 recorded highest leaf proportion (57.27) above others. Varieties IT-193 with manure (80.00 cm) and IT-297 without manure (30) recorded significantly higher (P<0.05) values for plant height and leaf number respectively. Dry matter yield of cowpea ranged significantly higher (P<0.05) from 7.20 t ha-1 in variety IT-817 without manure to 14.85 t ha-1 in variety IT-321 with manure. The average crude protein content of improved cowpea varieties ranged significantly (P < 0.05) from 97.69 g kg-1 dry matter in unfertilized IT-817 and IT-834 to 141.17 g kg-1 dry matter in fertilized IT-819. The study showed that application of swine manure into cowpea increased the dry matter yield and chemical composition which is necessary to provide sufficient feed for ruminants that can be used as a supplement during the dry season.
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Dagari, M. S. y Mohammed Salisu Musa. "EFFECTS OF CALCIUM HYDROGEN PHOSPHATE ON LEAD UPTAKE BY COWPEA (VIGNA UNGUICULATA)". FUDMA JOURNAL OF SCIENCES 4, n.º 3 (11 de septiembre de 2020): 36–42. http://dx.doi.org/10.33003/fjs-2020-0403-349.
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The effects of calcium hydrogen phosphate on lead (Pb) uptake by cowpea (Vigna unguiculata) were investigated in a growth chamber experiment coupled with atomic absorption spectrophotometry (AAS) and colorimetry analyses. Cowpea seeds were planted and harvested in soil samples treated with Pb+2 added as lead nitrate at the rates of 0, 1000 and 3000 mg/kg followed by calcium hydrogen phosphate (CaHPO4) at 0, 10, 50 and 250 mg/kg. Increases in shoot yield brought about by phosphate fertilization were observed to oppress the shoot lead concentration as a result of growth dilution, where the actual amount of lead in shoots was unaffected by phosphate treatment. This work revealed that there is no substantial effect on lead uptake by cowpea, as a result of phosphate fertilization. Therefore, phosphate fertilization is a good means of cowpea production with minimal lead uptake and hence safe for human consumption
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Ravelombola, Waltram, Ainong Shi, Jun Qin, Yuejin Weng, Gehendra Bhattarai, Bazgha Zia, Wei Zhou y Beiquan Mou. "Investigation on Various Aboveground Traits to Identify Drought Tolerance in Cowpea Seedlings". HortScience 53, n.º 12 (diciembre de 2018): 1757–65. http://dx.doi.org/10.21273/hortsci13278-18.
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Impacts of drought stress on crop production can significantly impair farmer’s revenue, hence adversely impacting the gross national product growth. For cowpea [Vigna unguiculata (L.) Walp.], which is a legume of economic importance, effects of drought at early vegetative growth could lead to substantial yield losses. However, little has been done with respect to breeding for cowpea cultivars withstanding drought at early vegetative growth. In addition, previous investigations have focused on how plant morphology and root architecture can confer drought tolerance in cowpea, which is not sufficient in efforts to unravel unknown drought tolerance–related genetic mechanisms, potentially of great importance in breeding, and not pertaining to either plant morphology or root architecture. Therefore, the objective of this study was to evaluate aboveground drought-related traits of cowpea genotypes at seedling stage. A total of 30 cowpea genotypes were greenhouse grown within boxes and the experimental design was completely randomized with three replicates. Drought stress was imposed for 28 days. Data on a total of 17 aboveground-related traits were collected. Results showed the following: 1) a large variation in these traits was found among the genotypes; 2) more trifoliate wilt/chlorosis tolerance but more unifoliate wilt/chlorosis susceptible were observed; 3) delayed senescence was related to the ability of maintaining a balanced chlorophyll content in both unifoliate and trifoliate leaves; and 4) the genotypes PI293469, PI349674, and PI293568 were found to be slow wilting and drought tolerant. These results could contribute to advancing breeding programs for drought tolerance in cowpea.
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Maduwanthi, A. K. M. R. B. y Brintha Karunarathna. "Growth and Dry Matter Accumulation of Okra (Abelmoschus esculentus L.) as Influenced by Different Plating Pattern Under Okra - Cowpea (Vigna unguiculata L.) Intercropping". Journal of Horticulture and Plant Research 7 (agosto de 2019): 81–96. http://dx.doi.org/10.18052/www.scipress.com/jhpr.7.81.
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Compared to sole cropping, intercropping systems can more efficiently use the existing resources which ultimately lead to improved plant growth and dry matter accumulation. So, most of the farmers in developing countries can follow the intercropping systems with high yielding crop combinations. The experiment was carried out at the Crop Farm of Eastern University, Sri Lanka in 2018 to investigate the growth and dry matter accumulation in okra (Abelmoschus esculentus L.) as influenced by different planting patterns under okra-cowpea (Vigna unguiculata L. Walp) intercropping in sandy regosol. The experiment was laid out in a Randomized Complete Block Design (RCBD). Treatments were okra as a sole crop (T1), cowpea as a sole crop (T2), alternative planting of okra and cowpea (T3), 60/150 cm paired row planting of okra with two rows and three rows of cowpea in between paired rows (T4 and T5) and 75/120 cm paired row planting of okra with two rows and three rows of cowpea in between paired rows (T6 and T7). Plant height, root length, fresh and dry weights of plant, leaf area, leaf area index, canopy width and cumulative yield of okra were higher in T5, while chlorophyll content showed no significant difference (P>0.05) with different planting patterns. The present study concluded that 60/150 cm paired row planting of okra with three rows of cowpea in between paired rows (T5) would be the most suitable planting system in sandy regosol to achieve better growth and dry matter in okra.
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WARDROP, Alison J., Ronald E. WICKS y Barrie ENTSCH. "Occurrence and expression of members of the ferritin gene family in cowpeas". Biochemical Journal 337, n.º 3 (25 de enero de 1999): 523–30. http://dx.doi.org/10.1042/bj3370523.
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Ferritin gene expression has been demonstrated in a variety of plants including maize, Arabidopsis, cowpeas, soybeans, beans and peas. Most available evidence shows that the mature protein is located in plastids and its production is under gene transcriptional control. In maize, two different ferritin genes have been identified; they were found to express protein under different physiological conditions. Only single gene products have been found until now in the other plants, with the exception of cowpeas (Vigna unguiculata). Our previous work with cowpeas [Wicks and Entsch (1993) Biochem. Biophys. Res. Commun. 192, 813–819] showed the existence of a family of at least three ferritin genes, each coding for a protein subunit with a unique amino acid sequence. Here we report the discovery of a fourth active gene in cowpeas and present the full cDNA sequences for two of the four known members of the cowpea gene family. We also provide preliminary evidence for a family of ferritin genes in soybeans (Glycine max) related to that in cowpeas. We conclude that a family of genes is probably present in all higher plants. We have used quantitative reverse transcriptase-mediated PCR to show that each of the four members of the cowpea ferritin gene family expresses mRNA in leaves and roots under normal growth with a complete nutrient supply. The results clearly show a marked differential pattern of mRNA levels formed during development from the four genes. We conclude that the composition of plant ferritin molecules from plant leaf extracts is probably a complex mixture of subunits, which might be different in roots and in leaves.
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Miranda, Rafael de Souza, Fabricio Bonfim Suderio, Elton Camelo Marques y Eneas Gomes-Filho. "ACCUMULATION AND PARTITION OF Fe, Zn, Cu, Mn AND Na IN MACRO AND MICRONUTRIENT-DEFICIENT COWPEA PLANTS". JOURNAL OF ADVANCES IN AGRICULTURE 7, n.º 2 (22 de julio de 2017): 1036–43. http://dx.doi.org/10.24297/jaa.v7i2.6237.
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Cowpea (Vigna unguiculata) is an important crop for people living in the semi-arid tropics where it is used as food, animal feed and forage. Researches related to nutritional status of plants are important, principally in crops commonly grown in nutrient-poor soils. This study aimed to analyze the growth and accumulation/distribution of some micronutrients in cowpea plants submitted to macro and micronutrient deficiency. Cowpea seeds were germinated in grit and after five days, ten uniform seedlings were transferred to complete nutrient solution for an acclimatization period. After three days, the plants were grown in nutrient solution containing all macro and micronutrients or in nutrient solution without N, Ca, K, Mg, P, S, Fe, B or aeration. In all case, omission of mineral nutrients and the aeration caused reductions in the dry mass of cowpea plants, except for B; however, the absence of Ca was the most limiting for plant growth. Interestingly, the root Fe content significantly increased in Mg-, P- and S-deficient plants. Yet, Fe-deficient plants displayed a significant increase in Cu and Mn content, regardless of plant organ. Our data clearly demonstrate that the Ca is the most important nutrient for V. unguiculata growth, followed by N and Fe. The accumulation and partition of Fe, Zn, Cu and Mn in cowpea vary differentially in root, stem and leaf as affected by nutritional deficiency.
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Wilson, Clyde, Xuan Liu, Scott M. Lesch y Donald L. Suarez. "Growth Response of Major U.S. Cowpea Cultivars. I. Biomass Accumulation and Salt Tolerance". HortScience 41, n.º 1 (febrero de 2006): 225–30. http://dx.doi.org/10.21273/hortsci.41.1.225.
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Over the last several years, there has been increasing interest in amending the soil using cover crops, especially in desert agriculture. One cover crop of interest in the desert Coachella Valley of California is cowpea [Vigna unguiculata (L.) Walp.]. Cowpea is particularly useful in that as an excellent cover crop, fixing abundant amounts of nitrogen which can reduce fertilizer costs. However, soil salinity problems are of increasing concern in the Coachella Valley of California where the Colorado River water is a major source of irrigation water. Unfortunately, little information is available on the response of cowpea growth to salt stress. Thus, we investigated the growth response of 12 major cowpea cultivars (`CB5', `CB27', `CB46', `IT89KD-288', `IT93K-503-1', `Iron Clay', `Speckled Purple Hall', `UCR 134', `UCR 671', `UCR 730', `8517', and `7964') to increasing salinity levels. The experiment was set up as a standard Split Plot design. Seven salinity levels ranging from 2.6 to 20.1 dS·m–1 were constructed, based on Colorado River water salt composition, to have NaCl, CaCl2 and MgSO4 as the salinization salts. The osmotic potential ranged from –0.075 to –0.82 MPa. Salt stress began 7 days after planting by adding the salts into irrigating nutrient solution and ended after 5 consecutive days. The plants were harvested during flowering period for biomass measurement (53 days after planting). Data analysis using SAS analysis of variance indicated that the salinity in the range between 2.6 and 20.1 dS·m–1 significantly reduced leaf area, leaf dry weight, stem dry weight and root dry weight (P ≤ 0.05). We applied the data to a salt-tolerance model, log(Y) = a1 + a2X + a3X2, where Y represents biomass, a1, a2 and a3 are empirical constants, and X represents salinity, and found that the model accounted for 99%, 97%, 96%, 99%, and 96% of salt effect for cowpea shoot, leaf area, leaf dry weight, stem dry weight and root dry weight, respectively. We also found significant differences (P ≤ 0.05) of each biomass parameter among the 12 cultivars and obtained different sets of the empirical constants to quantitatively describe the response of each biomass parameter to salinity for individual cowpea cultivars. Since a significant salt × cultivar interaction effect (P ≤ 0.05) was found on leaf area and leaf dry weight, we concluded that salt tolerance differences exist among the tested cultivars.
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Maria Simões de Siqueira, Kércya y Mário Massayuki Inomoto. "Pathogenicity and reproductive fitness of Pratylenchus brachyurus on cowpea". Nematology 10, n.º 4 (2008): 495–500. http://dx.doi.org/10.1163/156854108784513897.
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AbstractThe lesion nematode Pratylenchus brachyurus is widespread in cowpea plantations throughout the tropics and sub-tropics. However, the pathogenicity of P. brachyurus on cowpea has been scarcely studied. In this work, it was demonstrated in two glasshouse experiments that an isolate (Pb20) of P. brachyurus was pathogenic to cowpea cv. IPA-206, adversely affecting the plant growth and pod formation and filling. Initial population levels of 5000 and 15 000 nematodes per plant caused reduction of root growth and typical decay of root tissue. The third experiment demonstrated that all six cowpea cultivars selected for evaluation supported reproduction of three isolates of P. brachyurus (Pb20, Pb21 and Pb23) in their roots, although the reproduction factor values obtained indicated that they were dissimilar in their reproductive fitness. Low resistance to P. brachyurus was reported for at least one tested cultivar, but apparently of an insufficient degree to be effective for field management of the nematode.