Stylosanthes Gracilis Research Articles

Effect of inhibitor concentration on the potency of stylosanthes gracilis extract as corrosion inhibitor for AISI 304l in sulphuric acid solution

Effect of inhibitor concentration on the potency of Stylosanthes gracilis extract as corrosion inhibitor for AISI 304l in sulphuric acid solution was purposefully undertaken in order to explore and unearth the worthiness of the extract as a potent green inhibitor. The study was accomplished using weight loss and potentiodynamic polarization methods. It was observed that the potency of the extract increased with increasing concentration up to an optimum concentration of 1.2g/L after which the inhibitor became negative in approach. Potentiodynamic polarization parameters behaved in such a manner that affirmed that the extract is a potent green inhibitor against the corrosion of alloys 304L in the stated sulphuric acid solution. Calculated value of the change in corrosion potential showed that the action of the inhibitor is a mixed type. Both the weight loss and potentiodynamic polarization methods identified 1.2g/L as the optimum concentration.

Composição florística de uma comunidade savânica no Rio Grande do Norte, Nordeste do Brasil

No município de Rio do Fogo foi registrada, em 1976, somente através de imagens de radar, uma comunidade de Cerrado para a qual, até então, não havia estudo in loco. Algumas questões foram elaboradas sobre essa comunidade: A região delimitada e descrita por meio de imagens de radar pode ser considerada Cerrado, do ponto de vista florístico? Qual a fitogeografia das espécies registradas nessa comunidade? Há ocorrência de espécies raras, endêmicas ou ameaçadas de extinção na composição florística dessa comunidade? Para responder a estas questões realizou-se o levantamento florístico em 400 ha, no período de agosto/2007 a setembro/2009. Os dados indicaram que das 94 espécies registradas em Rio do Fogo, 73 são associadas ao Cerrado, 69 também se distribuem na Caatinga, 60 na Floresta Atlântica, 47 na Floresta Amazônica, 14 no Pantanal e 11 no Pampa. Foram listadas pela primeira vez para o Rio Grande do Norte (RN) 39 espécies; Stylosanthes gracilis Kunth (Fabaceae) e Aristida laevis (Nees) Kunth (Poaceae) são citadas pela primeira vez para o Nordeste do Brasil. Aspilia procumbens Baker (Asteraceae) apresentou distribuição restrita ao estado e insere-se na categoria criticamente em perigo; já Stilpnopappus cearensis Hubber na categoria vulnerável à extinção. Concluiu-se que essa área pode ser classificada floristicamente como pertencente ao domínio do Cerrado, podendo ser apontada como área-chave para a conservação.

Evaluation of Biological Soil Fertility Management Practices for Corn Production in Oxisols

Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinica, Tithonia diversifolia, Stylosanthes gracilis and a mineral combination of nitrogen and phosphorus (NP) (115-63-0) along with a control (without fertilization) were evaluated for corn crop growth and production. The field trial was a completely randomized design with four replicates. Plant height, basal stem diameter, and yield components were assessed. Irrespective of fertilization treatments and variety, maize showed a similar growth up to 20 days after sowing (DAS), and then two distinct trends were observed. At 60 DAS, plant height and basal diameter were significantly bigger in plots treated with NP, T. diversifolia and E. abyssinica compared to S. gracilis treatment and control (NoF). This pattern was also confirmed with agronomic traits such as cob length, number of kernel per cob, and net grain yield. The local variety was the least productive under any treatment. In general, the response of corn crop to organic and inorganic fertilization showed that the mineral combination (NP) increased the most grain yield and other yield components compared to unfertilized trial, followed by T. divessifolia and E. abyssinica. NP and T. diversifolia treatments increased significantly and equally soil potassium content compared to control and other treatments. Application of T. diversifolia appears a more cost effective approach for small farmers to improving fertility of the oxisol prevailing in Central Africa compared to mineral fertilizers.

Comparative study of soil properties under various cultivation regimes of different crops

Establishment of cover crops is an effective way to reverse the soil fertility decline, which can be caused by a range of inappropriate traditional agriculture practices, particularly tillage and inorganic fertiliser application. In this study, soil properties were assessed under various cultivation regimes of different crops, including legumes, grass, and nursery natural rubber (NR) trees (Hevea brasiliensis Muell. Arg.), in southern Vietnam. The crops studied had all been growing for 7 years commencing in 1999, on light-textured Acrisols. Soils under the cultivation regime of creeping legumes including Calopogonium caeruleum, Pueraria phaseoloides, and Stylosanthes gracilis had significantly higher carbon (C) and nitrogen (N) concentrations and porosity than soils under the other management types studied. Soils under Brachiaria ruziziensis and P. phaseoloides had the highest aggregate stability. Cultivation regimes with tillage, field traffic, and inorganic fertilisers applied to nursery NR trees increased phosphorus (P) availability, but this was accompanied by increased soil compaction and reductions in most of the other soil properties analysed. Relative to the nursery NR cultivation, creeping-legume cultivation increased soil C concentration (by 95%), soil pHH2O (by 19%), macro-aggregates (by 29%), and porosity (by 8%). From principal component analysis, three soil properties—soil organic carbon (SOC), porosity, and P availability—were selected as key indicators suitable for the evaluation of the effects of cultivation on soils. Establishment of C. caeruleum and B. ruziziensis was most effective in improving soil C content, and soil porosity was significantly higher under C. caeruleum and P. phaseoloides. These findings suggest that each cover crop had its own dominant agro-characteristics and that selection of a cover crop to either improve soil fertility or reduce compaction should be considered by farmers in this region.

Re-establishment of Stylosanthes gracilis (Leguminosae) at species level

In most taxonomic revisions of Stylosanthes Sw., Stylosanthes gracilis Kunth has been regarded as a variety or even a synonym of S. guianensis (Aubl.) Sw. This has created considerable confusion among scientists working with the latter species which is an agriculturally important tropical forage and cover legume. This study collected taxonomically relevant evidence, for evaluating S. gracilis as a valid species. Since the type specimen is lost, a collection from the same location as the original type is proposed here as a neotype.

Influence of an Arbuscular Mycorrhizal Fungus on Competition for Phosphorus Between Sweet Orange and a Leguminous Herb

ABSTRACT Grass or herb intercropping with trees is widely practiced as an orchard-floor management strategy, but nutrient competition from grass species can inhibit the growth of intercropped fruit trees. Two experiments were conducted to investigate whether inoculation with the arbuscular mycorrhizal (AM) fungus Glomus versiforme can alleviate such competition and thus promote the growth of intercropped fruit trees by increasing soil nutrient exploitation. In the first experiment, intercropping was established in rhizoboxes containing sweet orange (Citrus sinensis) and the leguminous herb Stylosanthes gracilis inoculated with the AM fungus. Mycorrhizal inoculation did not appear to decrease competition, but increased the biomass of the herb much more than that of sweet orange. Inoculation had little effect on phosphorus (P) content of sweet orange, but significantly increased that of the legume roots. The AM fungal contribution to P uptake of the herb was twice that of sweet orange. Lateral roots of the herb tended to branch horizontally, with a large proportion entering the soil volume occupied by sweet orange; AM inoculation enhanced this effect. In Experiment 2, growth of the plants in monoculture revealed that the mycorrhizal dependency of the legume was much higher than that of sweet orange. It is suggested that mycorrhizal dependency can have a large influence on the role of the AM fungus in mediating competition in an intercropping system, and that fruit trees with high mycorrhizal dependency, together with a grass or herb with low mycorrhizal dependency, may be the optimum intercrop combination in orchards.

Rumen degradability characteristics of <I>Stylosanthes gracilis, Panicum maximum, Pennisetum purpureum</I> and <I>Centrosema pubescens</I> in sheep

The rumen degradability of four common Nigeria forages namely, Stylosanthes gracilis, Panicum maximum, Pennisetum purpureum, Centrosema pubescens were studied. The rumen degradability of the crude protein (CP), dry matter (DM) and organic matter (OM) contents of these forages were measured in four rumen-fistulated sheep weighing 9.6±0.07kg and using the nylon bag technique. A 4 x 4 latin square experimental design was used where four replicates of each forage were put in nylon bags measuring 7.5 x 10cm and incubated in the rumen of four sheep. The percentage disappearance of crude protein, dry matter and organic matter were monitored by withdrawing each bag at different time internals of 4, 8, 24 and 48hrs. The percent potential degradability of the forages at 48hrs were as follows: S. gracilis , CP (67%); DM (75%); OM (63%-); P. maximum , CP (57%), DM (50.12%), OM (40.36%); P. purpureum , CP (66%), DM (62.13%), OM (58.36%); C. pubescens , CP (50.7%), DM(51.1%), OM(51.06%). The DM and OM potential degradability for S. gracilis was significantly (p C. pubescens and P. maximum . There was however no significant (p>0.05) difference in the OM degradability of S. gracilis and P. purpureum . There was an inverse relationship between the crude fiber content of forages (Legumes and Grasses) and their rumen degradability. The data obtained in this study will help in formulating forage based diets that provide adequate rumen degradable and by pass proteins for optimum growth and productivity KEY WORDS: Rumen, sheep, degradability Nigerian Veterinary Journal Vol.25(1) 2004: 14-20

Response of Soyabean Crops to Mucuna pruriens Green Manure in Symbiosis with Cowpea Bradyrhizobia in Congo

ABSTRACT The use of Mucuna pruriens as source of N for the succeeding poor N-fixing soyabean genotypes was tested during the 1991/92 rainy season at the IDR site. Field studies revealed that M. pruriens produced 31 nodules plant−1 with a nodule mass of 306 mg plant−1 and a crop N yield of 340 kg ha−1. This high nodulation was attributed to a wide range of indigenous rhizobia identified as strains of Bradyrhizobia isolated from nodules of Stylosanthes gracilis (two isolates G7, G71), Crotalaria juncea (two isolates C4, C41), M. pruriens (two isolates II, 13), Mimosa pudica (three isolates W3, W31, W32) and Phaseolus vulgaris (one isolate H51), which formed nodules with dark red interiors on M. pruriens as revealed by the plant-infection test. The antibiotic resistance profile differed among the various isolates, and among isolates of the same plant of origin. Consequently, the use of Mucuna as green manure for the succeeding soyabean crops is quantified as a fertilizer-N equivalent of as much as 95 and 80 kg N ha−1 for genotypes cv. FN3 and cv. IRAT 274 respectively. Our findings illustrate the high agronomic efficiency of M. pruriens for soyabean.

Genetic relationships and variation in the Stylosanthes guianensis species complex assessed by random amplified polymorphic DNA

Genetic variation in the five taxonomic groups of the Stylosanthes guianensis (Aubl.) Sw. complex was investigated using random amplified polymorphic DNA markers (RAPDs). DNA samples from four plants of each of 45 accessions within the S. guianensis species complex were analyzed using 20 oligonucleotides of random sequence. Little variation was found within each of the 18 accessions (1-7% of total RAPD bands in pairwise comparisons) and none within each of the other 27 accessions. However, higher levels of polymorphisms were observed both within (index of genetic distance = 1 - F = 0.16-0.248) and between (1 - F = 0.254-0.408) the five taxa. This level of differentiation at the DNA level supported an earlier classification of the taxa as distinct species. A phenogram based on band sharing was constructed to show genetic relationships among the taxa studied. This phenogram corroborated the description of relationships based on morphological-agronomic characteristics, seed protein patterns, rhizobial affinities, crossability, and pollen stainability of the hybrids. In this phenogram, the most similar species were S. grandiflora and S. hippocampoides (1 - F = 0.264), with S. acuminata also showing closest similarity to these two species (1 - F = 0.277 and 0.283, respectively). Stylosanthes gracilis accessions showed the closest similarity (1 - F = 0.296) to S. guianensis ssp. guianensis accessions. Lowest similarity values (1 - F = 0.335-0.411) were found between these two species and S. grandiflora, S. acuminata, and S. hippocampoides.

Título en español

Un experimento en un suelo Ultisol de la región húmeda montañosa de Puerto Rico se realizó para evaluar el potencial de producción de forraje y proteína bruta de cinco selecciones de la leguminosa Stylosanthes guianensis, una de Stylosanthes gracilis y la gramínea Digitaria milanjiana USDA PI 299699. En el primer período experimental, las forrajeras se cortaron nueve y seis veces cada 45 y 65 días, respectivamente. Durante el segundo período, se cortaron 5 y 4 veces cada 65 y 79 días respectivamente. Las parcelas de leguminosas recibieron 112 kg por ha y año de fósforo y potasio en una sola aplicación. Las de la gramínea recibieron 3,360 kg por ha y año de un abono 15-5-10; se aplicó la cantidad indicada después de cada corte, según el intervalo asignado. Las parcelas no se regaron en ninguno de los períodos experimentales. La gramínea D. milanjiana sobrepasó significativamente en producción de forraje verde y seco las seis selecciones de Stylo a los 3 intervalos de 45, 65 y 79 días. La gramínea produjo 29,574 y 29,920 kg/ha en 13.5 meses cuando se cortó cada 45 y 65 días, respectivamente. A intervalos de 79 días, produjo 25,046 kg por ha en un período de 10.5 meses. Las leguminosas más productivas de forraje seco fueron la cultivar Fine Stem (IRFL-1416), S. guianensis USDA PI 361877 y las cultivares comerciales Endeavour y Schofield. La cultivar Fine Stem produjo rendimientos de 18,522 y 18,936 kg/ha en 13.5 meses, que pueden considerarse altos para una leguminosa tropical. Cuatro de las cultivares produjeron casi tanta proteína bruta como la D. milanjiana al cortarse cada 45 días, mientras que a intervalos de corte de 65 y 79 días todos se acercaron a la gramínea en este criterio. En la época lluviosa surgió un brote de antracnosis que redujo el crecimiento de las seis leguminosas, pero en menor grado a las cultivares Endeavour y Fine Stem. Se sugiere cortar la leguminosa cada 65 días. Al cortarse cada 45 días, los yerbajos tienden a invadirla despues del año. A intervalos de 79 días, la leguminosa tiende a producir menos forraje y proteína bruta que cuando se corta cada 65 días. Se presenta el contenido en nitrógeno, fósforo, potasio, calcio y magnesio de las leguminosas y la gramínea para los tres intervalos de corte estudiados. En general, las cultivares arrojaron marcadamente mayores contenidos en nitrógeno, calcio y magnesio que la gramínea D. milanjiana.

THE RHIZOBIUM REQUIREMENTS OF THE NON‐LEGUME PARASPONIA IN RELATIONSHIP TO THE CROSS‐INOCULATION GROUP CONCEPT OF LEGUMES

Summary Parasponia andersonii was nodulated by thirty four of thirty nine slow‐growing rhizobia isolated from tropical legumes and by R. japonicum and JR. lupini. The nitrogenase activity of nodulated plants within a rhizobial treatment varied widely. Effective associations were obtained with some but not all isolates from Cajanus cajan, Centrosema pubescens, Crotalaria anagyroides, Flemingia congesta, Inocarpus fragiferum, Macroptilium lathyroides, Phaseolus calcaratus, Stizolobium deeringianum and Stylosanthes gracilis. Little or no nitrogen was fixed with rhizobia from Albizia stipulata, Cassia mimosoides, Desmodium microphyllum, Pterocarpus indicus, Uraria lagopoides, and the wide‐host range cowpea Rhizobium strain CB 756. Fast‐growing rhizobia from Leucaena leucocephala, Mimosa invisa, M. pudica, Sesbania grandiflora and Lablab pur‐pur eus nodulated Parasponia with a low level of nitrogen fixation.Isolates from Parasponia failed to nodulate most of the legumes usually nodulated by slow‐growing rhizobia and when tropical legumes were nodulated, the association was either partially effective or ineffective; only isolate CP 283 was highly effective and promiscuous. Hosts normally nodulated with fast‐growing rhizobia, including Leucaena and Mimosa were not nodulated with isolates from Parasponia.It was concluded that the Parasponia‐Rhizobium symbiosis is best located in the ‘cowpea miscellany’.

Nitrogenase activity in rhizobium associated with leguminous and non-leguminous tissue cultures

Nitrogenase activity was observed in root-, stem- and leaf-tissue cultures of three genetic lines of Trifolium pratense infected with Rhizobium trifolii Rothamsted Strain 5, Stylosanthes gracilis with Rhizobium sp. Strain CB1552 and root-tissue cultures of carrot with Strains CB1552 and NGR99. Rhizobium (CB1552) previously associated with Stylosanthes tissues continued to show nitrogenase activity for 5 days after separation from the callus. Infected Trifolium callus differentiated to produce roots in 8 weeks on a medium free from NO 3 −, 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin, whereas the uninfected callus remained undifferentiated.

Pasture productivity in Nigeria: I. Dry matter production and chemical composition of herbage

SUMMARYThe yields of four tropical grass/legume pasture mixtures were studied over a 4-year period. These mixtures had the following composition: H, Cynodon nlemfuensis var. robustus, together with the legumes Centrosema pubescens (Benth.), and Stylosanthes gracilis (H.B.K.); J, Pennisetum purpureum (Schum.) plus the two legumes in H; K, treatment J mixture plus Panicum maximum (Jacq.); and L, a mixture of treatments H, J and K. Each treatment paddock was grazed in rotation between 19 April 1966 and 21 November 1969.The mean annual dry-matter yields over the 4 years of grazing were approximately 37 ± 5·7, 41 ± 2·6, 44 ± 10·2 and 47 ± 8·7 t/ha for treatments H, J, K and L respectively. The overall mean for the four treatments was 42 ± 5·1 t/ha/annum.It was observed that the dry-matter yield of the three mixtures in J, K and L, containing the tall grass species, was significantly superior to that of treatment H; however, they were not statistically different among themselves.After the second year of grazing Stylosanthes gracilis diminished gradually and it was almost absent from the swards by the final year of grazing, while Centrosema pubescens maintained its stand throughout the experimental period.With the exception of phosphorus and sodium, levels of mineral elements in the pastures were above the recommended allowances for various classes of livestock.The average level of zinc was only slightly below the recommended value.

Effect of phosphorus on the growth and mineral composition of four tropical forage legumes

AbstractThe effect of phosphorus on the growth and mineral composition of four tropical pasture legumes—Centrosema pubescens, Centrosema plumeris, Puereria phaseoloides and Stylosanthes gracilis—was investigated in the greenhouse. All the species except P. phaseoloides responded to phosphorus application. C. pubescens required more phosphorus for optimum growth than C. plumeris and S. gracilis which required about the same amount.In the species, the potassium, sodium and calcium concentrations in plants given phosphorus seemed higher than that of the control except in S. gracilis where the potassium, and in C.plumeris where the calcium, concentration appeared to be lowered by phosphorus. The concentration of magnesium of C. plumeris seemed to be increased but unaffected in other species by phosphorus addition. Phosphorus tended to depress plant sulphur but it had no effect on percent nitrogen.The percentages of phosphorus, in the species for maximum growth at 65 days from sowing were: C. pubescens, 0.293; P. phaseoloides, 0.228; C. plumeris, 0.280; and S. gracilis, 0.270.

Studies on Groundnut Mosaic Virus of Arachis hypogaea L. in West Malaysia

SUMMARYA previously undescribed mosaic disease was observed on groundnut plants in several districts of West Malaysia. The virus was transmissible through sap, grafting and the aphids Aphis craccivora, A. gossypi, Myzus persicae, Rhopalosiphum maidis and Toxoptera citricidus. A. craccivora, the principal vector, shows dual transmission. The host range of the virus included mostly leguminous plants such as Glycine max, Cassia occidentalis, Crotalaria anagyroides, Indigofera hirsuta, Stylosanthes gracilis and Phaseolus vulgaris, and a non-leguminous host Chenopodium amaranticolor. The longevity in vitro of the virus was between 40–48 hours, its thermal end-point between 63° and 65°C and the dilution end-point 10−4.

The production and management of Stylosanthes gracilis at Shika, Nigeria:I. In sown pastures

SUMMARYThe contribution of the legume Stylosanthes gracilis to the nitrogen economy of mixed swards was assessed under both cutting and grazing conditions. In a cutting experiment, carried out during two wet seasons, a S. gracilis/Chloris gayana sward gave the same yields of dry matter and crude protein as a C gayana sward receiving 75 lb N and 167 lb N/acre (84 kg, 187 kg/ha) respectively. Lower yields were obtained from mixed swards containing Centrosema pubescens and Desmodium scorpiurus.In a grazing experiment the mean live-weight production from a S. gracilis/Digitariasmutsii sward was equivalent to that produced from a pure grass sward receiving only 13 lb N per acre (5·9 kg/ha), although greater beneficial effects of the legume were apparent under high stocking conditions. In both experiments the legume tended to become dominant after 2 years.Herbage yields from a S. gracilis/C. gayana pasture were significantly increased by phosphorus and sulphur; S. gracilis was particularly responsive to these elements. Under lenient defoliation, nitrogen reduced the proportion of the legume in the mixed sward, although frequent defoliation reduced the harmful effect of the nitrogen.The results are compared with other published data and are discussed in terms of ways in which the grass/legume balance can be altered by different management practices.

The production and management of Stylosanthes gracilis at Shika, Nigeria:II. In savanna grassland

SUMMARYIn an 80 acres (32·4 ha) grazing trial carried out over a 2-year period significant increases in cattle live-weight gains were achieved following the oversowing of savanna grassland by 4 lb/acre (1·8 kg/ha) of Stylosanthes gracilis (stylo) seed. The beneficial effects of the stylo was particularly apparent during the early part of the dry season. The early growth and subsequent survival of the stylo was not outstanding.Better results were achieved in a second experiment where stylo was grown as a pure crop and ration-grazed in the dry season in association with unimproved savanna. The live-weight gain of cattle grazing the stylo only during the 12 h night period was the same as cattle receiving 1·8 lb (0·82 kg) whole cotton seed per day. In general, cattle live-weight gains were directly proportional to the time spent on the stylo.

Effect of pH on the growth, nodulation and nitrogen fixation of Centrosema pubescens and Stylosanthes gracilis

AbstractCentrosema pubescens and Stylosanthes gracilis were grown on two soils of different texture adjusted to pH values ranging from 5–7 to 8–0 by the addition of either dilute sulphuric acid or calcium carbonate. Centrosema grew best on a soil having final pH values of 6–1, while Stylosanthes grew best on a soil having a final pH value of 5–7. Nodulation followed a similar trend with dry matter yields but was increasingly suppressed by increases in pH, with complete suppression in some cases at pH8. Maximum nitrogen fixation in both cases occurred at a pH value of about 6.

The Biology and Behavior of Rhinocoris albopunctatus (Hemiptera: Reduviidae)

Rhinocoris albopunctatus Stål, a reduviid common in cotton plantations grown near pasture leys in which Stylosanthes gracilis is incorporated, was observed to be a predator of the larvae of Heliothis armigera (Hübner), Earias biplaga Walker, E. insulana Boisduval, and readily accepted larvae of Cryptophlebia leucotreta Meyrick, and the pink bollworm, Pectinophora gossypiella (Saunders), given to it. Its biology and behavior were studied in the laboratory and field. It was found to have 5 instars. Total duration of nymphal stages averaged 85.9 days. The common parasites recorded from its eggs were Hadronotus antestiae Dodd, Hadronotus sp., and Telenomus sp., all of the family Scelionidae. The reduviid was found to be polyphagous. It destroyed 40% of H. armigera larvae given to it.

Digestibility of tropical pasture mixtures using the indicator technique

SUMMARYChromic oxide was used to assess the herbage intake of three tropical pastures mixtures namely: Cynodon plectostachyum and Centrosema pubescens (E); E plus Stylosanthes gracilis; Digitaria decumbens plus Centrosema pubescens and Stylosanthes gracilis, by-White Fulani (Zebu) steers and the use of faecal nitrogen to estimate digestibility of grazed herbage.Chromic oxide recoveries in faecal organic matter ranged from 94·60% in treatment F to ca. 97·2 and 97·5% in treatments E and G respectively.Positive relationships were found to exist between faecal organic matter nitrogen and herbage organic matter digestibility. Correlation coefficients of the ‘local’ regression equations obtained were positive but of low magnitude in some instances. Estimated mean organic matter intake was comparable to, but slightly lower than, the figures for animals of corresponding live weights in temperate countries while digestible organic matter intake was much lower.The mean organic matter digestibility values were ca. 70·2 and 66·7% respectively for the two grazing seasons studied.