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Experimentos foram conduzidos em laboratório com o objetivo de determinar relações entre germinação de sementes de plantas daninhas e condutividade elétrica (CE). Foram usadas sementes de amendoim-bravo (Euphorbia heterophylla), carrapicho-de-carneiro (Acanthospermum hispidum), corda-de-viola (Ipomoea grandifolia), guanxuma (Sida rhombifolia), picão-preto (Bidens pilosa) e trapoeraba (Commelina benghalensis) recentemente colhidas. As sementes foram embebidas em água por períodos de 6 até 48 horas, na temperatura de 20 ºC, determinando-se a CE das sementes e os níveis de absorção de água. Depois disso, as sementes foram colocadas para germinar. Os maiores níveis de germinação, para sementes embebidas em água por 24 horas, foram obtidos para picão-preto (88%), amendoim-bravo (31%) e guanxuma (30%); e os menores, para corda-de-viola (5%), carrapicho-de-carneiro (4%) e trapoeraba (3%). As sementes das plantas daninhas avaliadas tendem a germinar totalmente com períodos de embebição a partir de seis horas, ao passo que a sua absorção tende a aumentar e a CE das sementes, a não acompanhar os níveis de absorção ao final de maiores períodos. O uso da condutividade elétrica merece maiores estudos, uma vez que pode contribuir para uma eficiente e mais rápida avaliação da dinâmica de bancos de sementes de plantas daninhas em lavouras. Experiments were carried out under laboratory conditions to determine relationships between weed seed germination and electrical conductivity (EC). Recently-picked seeds of Euphorbia heterophylla, Acanthospermum hispidum, Ipomoea grandifolia, Sida rhombifolia, Bidens pilosa and Commelina benghalensis were used. The seeds were soaked in water for periods of six up to 48 hours, at 20 ºC, to determine EC and water absorption levels and placed to germinate. The highest germination levels, for seeds soaked in water for 24 h, were obtained for B. pilosa(88%), E. heterophylla and S. rhombifolia (30%) and the lowest levels were obtained for I. grandifolia (5%), A. hispidum (4%) and C. benghalensis (3%). The weeds tested tend to germinate totally with a soaking periods > six hours, while water absorption tends to increase with CE tending not to accompany absorption levels at the end of longer periods. Further studies must be conducted on the use of electrical conductivity, what may provide an effective and faster evaluation of the dynamics of weed seed banks under a farming system.

The ethanolic extracts of the leaves and flowering tops of Acanthospermum hispidum showed varying degrees of activity against a wide range of pathogenic bacteria. The activity resided mostly in the polar fractions of the alcoholic extract, being only slight in the non-polar fractions. No activity was observed for the aqueous extract of the fresh plant material.

Foram desenvolvidos estudos com colunas de solo (Ø = 4 cm; h = 25 cm) em condições de laboratório, em Londrina, durante os anos de 1999 e 2000, utilizando-se o horizonte Bw de um Latossolo Vermelho. As seguintes plantas foram testadas: agriãozinho das pastagens (Synedrellopsis grisebachii), carrapicho-de-carneiro (Acanthospermum hispidum ), caruru roxo (Amaranthus hybridus), ordão-de-frade (Leonotis nepetifolia: ), losna branca (Parthenium hysterophorus), mamona (Ricinus communis), picão branco (Galinsoga parviflora) e trapoeraba (Commelina benghalensis ). Extratos aquosos da parte aérea das plantas (3 g em 150 mL) foram aplicados na superfície do solo e lixiviados com três volumes de poros de água destilada, em tratamentos com calcário na superfície. Avaliaram-se as alterações no pH do solo e os teores de cátions trocáveis (Ca, Al, K e Mg) em camadas do solo de 5 cm e na solução efluente. A calagem superficial (sem extrato vegetal) aumentou o pH e o Ca e diminuiu o Al apenas no local de aplicação e, em menor intensidade, na camada de 5-10 cm. Os extratos de plantas e calagem superficial aumentaram o pH e reduziram Al até 20 cm de profundidade. A mamona foi a planta invasora que apresentou a maior capacidade de transportar Ca, elevando a concentração do nutriente até 15 cm de profundidade. As plantas de maior efeito na acidez foram: picão branco e trapoeraba, que também causaram a maior lixiviação de Al da coluna de solo. As de menor efeito foram: agriãozinho e carrapicho-de-carneiro. As plantas invasoras testadas apresentaram potencial para uso, objetivando o aumento da eficiência da calagem na correção da acidez da subsuperfície do solo. Studies with soil columns (Ø = 4 cm; h = 25 cm) were carried out under laboratory conditions in the years 1999 and 2000, in Londrina, using the Bw horizon of a Red Latosol. The following weed species were tested: Synedrellopsis grisebachii, Acanthospermum hispidum, Amaranthus hybridus, Leonotis nepetifolia, Parthenium hysterophorus, Ricinus communis, Galinsoga parviflora and Commelina benghalensis. Shoot extracts (3 g in 150 mL of water) were applied onto the soil surface with a lime top dressing and then leached with three pore volumes of deionized water. Alterations of soil pH and exchangeable cation contents were determined, taking samples from soil layers of 5 cm and leached solutions from the columns. Liming without plant extracts increased soil pH and Ca and decreased Al in the top layer, and, less intense, in the 5-10 cm layer. Liming with plant extracts increased soil pH and reduced Al down to 20 cm of depth. Ricinus communis presented the greatest capacity as Ca carrier, increasing its content down to 15 cm of depth. G. parviflora and C. benghalensis reduced soil acidity most effectively and also stimulated highest Al leaching, while least effective weeds were S. grisebachii and A. hispidum. The tested plant extracts present potential to transfer lime alkalinity to acid soil subsurface.

Objetivou-se verificar a eficácia e a seletividade de herbicidas aplicados isoladamente ou em mistura, no controle de plantas daninhas infestantes da cultura do amendoim Runner IAC 886. Para tanto, instalou-se um experimento a campo, em delineamento de blocos casualizados, com quatro repetições. Os tratamentos aplicados em pré-emergência foram: 1-imazapic, 3-imazapic + pendimetalina e 5-imazapic + trifluralina; os aplicados em pós-emergência foram: 2-imazapic, 4-imazapic + pendimetalina e 10-imazapic + (bentazon + paraquat); e os tratamentos com aplicação em pré seguido de pós, foram: 6-trifluralina e imazapic, 7-trifluralina e bentazon, 8-trifluralina e 2,4-D, 9-imazapic e bentazon + paraquat; além das testemunhas com e sem capina (tratamentos 11 e 12, respectivamente). Foram avaliados a eficácia dos herbicidas e os sintomas de intoxicação nas plantas de amendoim por avaliações visuais aos 7, 14, 21, 28, 45 e 90 dias após a aplicação, e após a colheita, a produtividade de vagens. Os tratamentos 2, 3, 4, 5, 6, 7 e 8 não tiveram redução significativa na produtividade. O tratamento 10 foi o menos eficiente no controle das plantas daninhas e apresentou produtividade 47,3% menor que o tratamento 3 e 51,2% menor que a testemunha capinada. Conclui-se que para uma comunidade infestante composta principalmente por capim-carrapicho, carrapicho-de-carneiro, caruru, losna-branca, apaga-fogo e capim-pé-de-galinha, o melhor controle das plantas daninhas foi obtido por imazapic em pós-emergência; já a aplicação de imazapic + (bentazon + paraquat) em pós-emergência, não foi efetivo no controle das plantas infestantes, resultando em perdas de produtividade.

The leaves and stems of Acanthospermum hispidium were extracted with distilled ethanol using cold extraction and concentrated using a rotary evaporator at 37 0 C. The crude extract was partitioned successively using hexane, benzene and methanol. Fractions 19, 20 and 21 purified on Sephadex LH-20 gave a compound elucidated to be 1, 3, 6, 8-tetrahydroxyl-9-anthracene carbonaldehyde, using the state-of-art tools of spectrometry. The results of the antimicrobial test on the isolated compound show activity against P. mirabilis, B. subtilis, P. aeruginosa, C. albican, S. typhi and B. cereus at minimum inhibitory concentration (MIC) value of 100ppm. Keywords : Acanthospermum hispidum, Anthracene Carbonaldehyde, Antimicrobial Test, Minimum Inhibitory Concentration.

Um experimento foi conduzido em campo no período de 1982 a 1998, em Londrina-PR, com o objetivo de avaliar o efeito de diferentes sistemas de manejo de solo nas reduções anuais de um banco de sementes de plantas daninhas e seus períodos de sobrevivência, sendo as plantas daninhas manejadas através de herbicidas, e a seqüência anual de cultivo soja após trigo. Os tratamentos de manejo de solos foram: 1) semeadura direta; 2) arado de discos e grade niveladora; 3) grade aradora e grade niveladora; 4) escarificação e grade niveladora. O delineamento experimental foi o de blocos ao acaso, com quatro repetições. A identificação e contagem das sementes presentes no solo foram feitas em 1990, 1995 e 1998. As estimativas de sobrevivência (a 1% da população inicial) das gramíneas capim-marmelada (Brachiaria plantaginea) e capim-colchão (Digitaria horizontalis ), nos quatro sistemas de manejo, foram de 5 a 10 anos e 5 a 7 anos, respectivamente; as das espécies de folhas largas, como caruru (Amaranthus spp.), de 5 a 9 anos, carrapicho-de-carneiro (Acanthospermum hispidum ), de 7 a 9 anos, de 10 a 20 anos, e picão-preto (Bidens pilosa), de 3 a 4 anos, e a comelinácea trapoeraba (Commelina benghalensis) de 10 a 20 anos. As sementes de espécies de plantas daninhas apresentaram características distintas de sobrevivência, em função do manejo do solo, do controle ao longo dos anos e das características morfológicas e fisiológicas das sementes. A field experiment was conducted from 1982 to 1998, in Londrina-PR, Brazil, to evaluate the effects of different soil management systems on the survival of a weed seedbank, with the weeds managed by herbicides, and the annual sequence of crops consisting of soybean - wheat. The soil management treatments were: 1) no-till; 2) mouldboard; 3) heavy disc, and 4) chisel. The experimental design was a randomized complete block, with four replications. Seed identification and counting were performed in 1990, 1995 and 1998. Estimates of seed survival in soil (at 1% of the initial population) of grasses Brachiaria plantaginea and Digitaria horizontalis, in the four soil management systems, were from 5 to 10 years and from 5 to 7 years, respectively; broadleaved weeds, such as Amaranthus spp., from 5 to 9 years; Acanthospermum hispidum, from 7 to 9 years; Commelina benghalensis from 10 to 20 years; Bidens pilosa, from 3 to 4 years; and the Commelinaceae Commelina benghalensis from 10 to 20 years. The weed species seeds present special features of survival in the soil as a function of soil management, control strategies along the years, and morphological and physiological characteristics of the seeds.

The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the 1D14,15D5 conformation. The structures were elucidated using extensive spectroscopic analysis. Fil: Cartagena, Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina Fil: Bardon, Alicia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina Fil: Catalan, Cesar Atilio Nazareno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina Fil: J. de Hernández, Zaida N.. Instituto Politécnico Nacional; México Fil: Hernández , Luis R.. Instituto Politécnico Nacional; México Fil: Joseph Nathan, Pedro. Instituto Politécnico Nacional; México

Incubation of the alphaherpesviruses pseudorabiesvirus (PRV) and bovine herpesvirus 1 during infection of cell cultures with an extract prepared from the leaves of Acanthospermum hispidum impaired productive replication of these viruses in a concentration-dependent manner whereas propagation of classical swine fever virus, foot-and-mouth disease virus and vaccinia virus was not affected. The 50% inhibitory concentration for cell growth (IC50) was 107 +/- 5 microliters/ml, and the concentration reducing PRV yield by 1 log10 (90% effective concentration, EC90) was 8 +/- 3 microliters/ml. The selectivity index calculated as the IC50/EC90 ration was 13 +/- 4. Delineation of the mechanism of the antiviral activity demonstrated inhibition of alphaherpesvirus attachment to and, to a lesser extent, penetration into the cells. In contrast, viral gene expression was not inhibited by the extract when added after entry of virions into the target cells. Reduced antiviral activity of A.h. against PRV deletion mutants lacking glycoprotein C (gC) or glycoproteins gC, gE, gG and gI altogether indicated that gC alone and/or viral attachment complexes of which gC is a component constitute the target structures for A. hispidum.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:51:16Z No. of bitstreams: 1 S0100-83581995000100007.pdf: 587730 bytes, checksum: a9856d3b938e9048ab8120bfd608bcd9 (MD5) Made available in DSpace on 2013-08-22T18:51:16Z (GMT). No. of bitstreams: 1 S0100-83581995000100007.pdf: 587730 bytes, checksum: a9856d3b938e9048ab8120bfd608bcd9 (MD5) Previous issue date: 1995-01-01 Made available in DSpace on 2013-09-30T19:42:19Z (GMT). No. of bitstreams: 2 S0100-83581995000100007.pdf: 587730 bytes, checksum: a9856d3b938e9048ab8120bfd608bcd9 (MD5) S0100-83581995000100007.pdf.txt: 17754 bytes, checksum: a7658f8a679a00fc67d7356cdda4ede7 (MD5) Previous issue date: 1995-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:13:09Z No. of bitstreams: 2 S0100-83581995000100007.pdf: 587730 bytes, checksum: a9856d3b938e9048ab8120bfd608bcd9 (MD5) S0100-83581995000100007.pdf.txt: 17754 bytes, checksum: a7658f8a679a00fc67d7356cdda4ede7 (MD5) Made available in DSpace on 2014-05-20T13:13:09Z (GMT). No. of bitstreams: 2 S0100-83581995000100007.pdf: 587730 bytes, checksum: a9856d3b938e9048ab8120bfd608bcd9 (MD5) S0100-83581995000100007.pdf.txt: 17754 bytes, checksum: a7658f8a679a00fc67d7356cdda4ede7 (MD5) Previous issue date: 1995-01-01 Com o objetivo de encontrar um método alternativo de aplicação de herbicidas, estudou-se a eficiência do oxyfluorfen aplicado em três doses (0, 480 e 960g/ha) sob duas formas (pulverizado e veiculado em folha de papel) no controle em pré-emergência de Bidens pilosa, Desmodium tortuosum, Eleusine indica, Sida rhombifolia Amaranthus retroflexus, Acanthospermum hispidum e Digitaria horizontalis. A pulverização do oxyfluorfen foi realizada com o auxílio de um pulverizador, e sua veiculação foi feita através da determinação prévia da capacidade de embebição do papel. Obteve-se a concentração necessária da calda quando o papel atingiu completa embebição e então, escorrido o excesso, foi posto a secar na sombra. O delineamento experimental foi o inteiramente casualizado, com cinco repetições. Foram realizadas avaliações aos 30, 45 e 60 dias após a aplicação (DAA), e os resultados indicaram que os métodos de aplicação utilizados, assim como as doses, apresentaram excelente controle de B. pilosa, D. tortuosum, E. indica S. rhombifolia, D. horizontalis e A. retroflexus até 60 DAA, reduzindo tanto a densidade como o acúmulo de matéria seca. Quanto ao A. hispidum, ambos os métodos e doses não proporcionaram bom controle. Foi observado também que o papel utilizado como veículo do oxyfluorfen proporcionou redução na densidade de B. pilosa, E. indica, D. horizontalis e A. retroflexus e promoveu a germinação de S. rhombifolia e A. hispidum quando da avaliação aos DAA. Estes resultados demonstram a viabilidade de utilização de papel como veículo de aplicação do oxyfluorfen. A greenhouse assay was conducted to evaluate na alternative method for applying oxyfluorfen to control annual weeds. The experiment was in 3 x 2 factorial, in a completely randomized design, with three replications. The factors were: three doses of oxyfluorfen (0, 480 and 960g/ha) and two methods to apply the herbicide to the soil surface (sprayed or soaked in paper sheet). The weeds studied were Bidens pilosa, Desmodium tortuosum, Eleusine indica, Sida rhombifolia, Amaranthus retroflexus, Acanthospermum hispidum and Digitaria horizontalis. Weed control was evaluated at 30, 45 and 60 days after the herbicide application (DAA). The application methods, as well as the doses showed excellent control of B. pilosa, D. tortuosum, E. indica, S. rhombifolia, D. horizontalis and A. retroflexus up to 60 DAA, reducing the density as well as the dry matter surplus. on A. hispidum, both methods and doses did not show good control. It was also observed that the paper utilized as the oxyfluorfen vehicle produced density reduction in B. pilosa, E. indica, D. horizontalis and A. retroflexus and induced the germination of S. rhombifolia and A. hispidum when evaluated at 60 DAA. These results demonstrated the viability of paper as the oxyfluorfen application vehicle. UNESP FCAVJ UNESP FCAVJ

The essential oil of an Argentine collection of the annual herb Acanthospermum hispidum DC. (Asteraceae), which contains the sesquiterpenoids β-caryophyllene (35.2%), α-bisabolol (11.4%), and germacrene D (11.1%) as major constituents, displayed molluscicidal effects on an adult population of Biomphalaria peregrina Orbigny (LD50 37.8 μg/mL) and produced alteration of the feeding and oviposition behavior of the polyphagous insect Spodoptera frugiperda Smith when incorporated in the larval diet at 250 μg/g. In addition, a selective antibacterial activity was observed against pathogenic strains of Staphylococcus aureus and Enterococcus faecalis (MICs 62.5 and 125 μg/mL), but was inactive at 125 μg/mL against three beneficial lactic acid bacteria. Synergistic interactions were further validated by FIC index determination of the combination of the antibiotics oxacillin and gentamicin and the essential oil on the four pathogenic strains evaluated.

The essential oils from two members of the Asteraceae ( Acanthospermum hispidum DC. aerial parts, and leaves of Tithonia diversifolia (Hemsley) A. Gray), growing wild in Osun State, Nigeria, have been characterised by combined gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. Twenty-nine components have been fully identified and grouped into monoterpene hydrocarbons (22.2%), oxygenated monoterpenes (4.6%), sesquiterpenes hydrocarbons (58.2%) and oxygenated sesquiterpenes (10.8%) in A. hispidum. The main constituents of the oil were β-caryophyllene (28.0%), α-pinene (15.9%) and bicyclogermacrene (11.0%) among the hydrocarbon compounds, and bisabolol (8.9%) and carvacrol methyl ether (4.1%) among the oxygenated components. Tithonia diversifolia essential oil comprised seventeen components and was characterised by a predominant content of monoterpene hydrocarbons (87.9%), cis-β-ocimene (43.7%), α-pinene (28.6%) and limonene (12.0%) being the main compounds. Sesquiterpenes represented ca. 10% oil, as sum of hydrocarbons and oxygenated components. A new chemotype is established for T. diversifolia, while the Nigerian A. hispidum is being reported for the first time as a new source of essential oil with some distinction in composition from those of other sources.

Acanthospermum hispidum DC. exhibits several anatomical characters commonly met with in the family Asteraceae,e.g., (i) variety of trichomes, (ii) a ring of discrete vascular bundles, heterogenecus pericycle and resin ducts in the stem, and (iii) anomocytic stomata and absence of hypoderm in the leaf. These with some others can serve as a diagnostic combination of characters for the species. Among the latter, mention may be made of (i) absence of root-pith, (ii) trichome complement made up of glandular and non-glandular uniseriate hairs, (iii) resin ducts present in root, stem and leaf, (iv) collenchymatous stem hypodermis interrupted by chlorenchyma below the stomata, (v) trilacunar node, (vi) foliar supply disposed as a crescentic arc of three discrete vascular bundles, (vii) dorsiventral mesophyll, (viii) absence of hypoderm in the leaf, and (ix) superficial origin of cork cambium in root and stem.

Shade tolerance of 7 common weeds of the semiarid tropics was studied in the 1978-9 wet seasons using 4 or 5 shading levels in the range 0-10% of incident sunlight. Shading at the highest rate reduced plant ht. of Celosia argentea and Tridax procumbens, LAI of Digitaria ciliaris and Dactyloctenium aegyptium and DM production of D. ciliaris, D. aegyptium and Acanthospermum hispidum to 30, 20-30 and 20%, resp., of those of unshaded plants. Plant ht. of Cyperus rotundus and Amaranthus viridis was little affected, but shading markedly reduced LAI and DM production. Shading markedly reduced seed production in annual weeds and tuber production in C. rotundus. In general, dicotyledonous weeds were less sensitive to shading than were monocotyledonous weeds. It weas concluded that substantial weed suppression could be achieved by manipulating crop canopies. The agronomic significance of these results is discussed

The effects of bristly starbur interference with peanuts were studied from 1980 through 1983 on a Dothan sandy loam (Plinthic Paleudults). Peanut seed yields, which included kernels plus hulls, were reduced as bristly starbur densities increased from 2 to 64 plants/7.5 m of row. Full-season interference from 8, 16, 32, and 64 bristly starbur plants/7.5 m of row reduced peanut seed yields 14, 26, 43, and 50%, respectively. The seed yield of peanuts maintained weed free for 6 weeks after crop emergence was reduced by no more than 3% compared to peanuts maintained weed free for the entire season. Weed interference for 2 weeks after crop emergence reduced seed yield by an average of 4% over the 3-yr period, based on prediction equations. Bristly starbur interference for 13 weeks after crop emergence reduced peanut forage dry weight yield by 54%. Similarly, peanut interference for 13 weeks after emergence reduced bristly starbur forage dry weight yield by 32%. Bristly starbur density in the forage dry weight studies averaged 35/7.5 m of row. These bristly starbur were confined to a 35-cm band over the drill. Peanut density averaged 72/7.5 m of drill.

Field experiments were conducted from 1981 through 1983 on a Dothan sandy loam (Plinthic Paleudults) at Headland, Alabama, to investigate the effects of row patterns and weed management systems on weed control, peanut yield, and net returns to land and management. Treatments consisted of three row patterns, a) conventional 91-cm rows, b) dual twin 18-cm rows, and c) triple twin 18-cm rows, and six weed management systems ranging from none to various combinations of herbicide and mechanical inputs. The experimental area was naturally infested with bristly starbur (Acanthospermum hispidum DC), sicklepod (Cassia obtusifolia L.), Florida beggarweed [Desmodium tortuosum (Sw.) DC.], large crabgrass [Digitaria sanguinalis (L.) Scop.], and Texas panicum (Panicum texanum Buckl.). Results showed that weed control was affected somewhat by row patterns with broadleaf weeds being more responsive to row pattern manipulation than grass weeds. Weed fresh weights were generally lower as row patterns narrowed from conventional 91-cm spacing, however exceptions did occur. Highest yields and net returns were obtained when peanuts were planted in the dual twin 18-cm rows and weed management included benefin applied preplant incorporated, plus alachlor applied preemergence, and two timely cultivations.

It is well known that the accidental introduction of some plants into certain parts of the world has later led to noxious weed problems of varying degrees of acuteness. Concrol of such alien plants by cultural or chemical methods may be unsatisfactory or economically impracticable and recourse is made to biological methods in the form of insect enemies etc. It was in circumstances of this nature that the Government of Nigeria requested the C.I.B.C. to investigate the possibilities of the biological control of the weed Acanthospermum hispidum D.C. Despite the discouraging facts that the weed is an annual and related to plants of economic importance in the family Compositae, and that the entomological method is appropriately regarded as being of very restricted application in these instances, the nature of thc problem for Nigerian agriculture was such that a preliminary investigation of the status of the plant in its native South American home seemed warranted.

The results are presented of digestibility trials on silage samples made from the following materials: Andropogon gay anus, Chloris gayana (Rhodes grass), Hyparrhenia rufa (Jaragua grass), Panicum maximum (Guinea grass), Pennisetum pedicellatum, P. purpureum (Elephant grass). Sorghum vulgare (sorghum), Acanthospermum hispidum, Helianthus annuus (sunflower), Stizolobium sp. (velvet bean), Zea mays (maize) and mixtures of A. gayanus/P. pedicellatum, Arachis hypogoea (groundnut haulms)/P, pedicellatum. Sorghum vtdgare/Stizolobium sp., Z. mays/Vigna sinensis (cowpea). The results obtained, also the agronomic aspects of the subject and the use of the materials as fodder for cattle during the dry season are discussed.

The "Espinho-de-cigano" plant (Acanthospermum hispidum DC) is used throughout northeastern (NE) Brazil as a folk medicine for asthma. Although little is actually known about the effectiveness and safety of this plant extract product, it is possible to find numerous medicines prepared from it in public health services or in stores selling natural products. This study aimed to undertake a literature review relative to Acanthospermum hispidum covering the period between 1926-2006 within the areas of ethnobotany, phytochemistry and pharmacology. The objective was to contribute to a better knowledge of this species and its uses, as well as to aid in improving its performance as a natural medicine. The species is easily identifiable and grows abundantly during the rainy seasons in NE Brazil; is amenable to cultivation without lose of its phytochemical profile, and toxicological studies have showed its safety as a medicine (although more studies will be required in that direction). As such, the compilation of the accumulated knowledge concerning this species will aid in evaluating its pharmacological value, guaranteeing quality control of the final product, and in preparing recommendations for usages and dosages that offer both safety and efficiency to the user.

Goats were fed with fresh or dry A. hispidum at the rates of 5 and 10 g per kg per day for periods up to 38 days. The main signs of poisoning were jaundice, diarrhoea, weakness of the hind limbs and debility. The lesions consisted of necrosis and portal fibroplasia in the liver, dilatation and degeneration of the kidney tubules, atrophy of the testes, pulmonary haemorrhage and oedema and splenic haemosiderosis. These changes were accompanied by increases in the concentrations of aspartate aminotransferase, ammonia and bilirubin and decrease in the levels of total protein and calcium in the serum. Haematological changes indicated the development of haemolytic anaemia.

Fifty albino mice were fed with the shoots of Acanthospermum hispidum as 50, 30, 10, 5 and 1 per cent and seeds as 50 per cent of the diet. All dose levels were toxic and caused death within 9 to 172 days. The outstanding signs of poisoning included diarrhoea, dyspnoea, alopecia and loss of condition. The lesions consisted of fatty change and necrosis in the liver, shrinkage of the renal glomerular tufts, haemorrhage and congestion in the spleen, lungs and heart and catarrhal enteritis.

The investigation of the aerial parts from ACANTHOSPERMUM HISPIDUM collected in Malawi afforded in addition to sesquiterpene lactones isolated previously from a collection in Bolivia three new ones. The structures were elucidated by highfield 1 H NMR.

Experiments were conducted on fallow tobacco ground in North Queensland to observe changes in volunteer fallow weed communities following the use of the chemicals pebulate, trifluralin, and benefin for weed control. Trifluralin and benefin repressed grasses and most broad-leaved weeds, resulting in almost complete pre-dominance of star burr (Acanthospermum hispidum), which is a noxious weed in Queensland. Pebulate showed good control of this weed and permitted a fallow dominated by green summer grass (Prachiaria miliiformis).