bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aspects of the biology of Ehrharta erecta Lam.
Authors: McINTYRE S. , LADIGES P. Y. 
Published: July 2006

SummaryField and laboratory studies of the South African grass Ehrharta erecta Lam. are presented. Seasonal growth and the soil seed bank were monitored at Mornington, Victoria, where E. erecta is naturalized beneath native Leptospermum laevigatum F. Muell. scrub. Adult plant growth commenced in late autumn, following a severe reduction in green shoot material resulting from drought damage. Seedlings emerged in autumn and winter and coincided with a significant decline in the soil seed bank.Germination trials indicated dormancy in fresh seed, which could readily be broken by a period of after‐ripening. Germination was also found to be inhibited by the presence of seed covering structures, but this effect diminished with time.A growth experiment conducted at different light intensities demonstrated a high level of shade tolerance in E. erecta with the compensation point ranging from 0·82 to 0·98% of full daylight. In view of the speciese’ shade tolerance and other evidence, it is hypothesized that the availability of water restricts the ability of E. erecta to grow under very dense canopies and controls its seasonal growth and regeneration pattern in the field.
Allelopathic effect of Salvia syriaca L. (Syrian sage) in wheat
Authors: QASEM J. R. , ABU‐IRMAILEH B. E. 
Published: July 2006

SummaryThe allelopathic effect of Salvia syriaca L. (Syrian sage) was examined against wheat in glasshouse and laboratory experiments. The germination of wheat grains was delayed, and the development of wheat seedlings was decreased in laboratory experiments by both shoot and rhizome extract. The inhibitory effect of both extracts was most pronounced at 20°C compared with 10 or 15°C. Shoot extracts had more drastic effects than the rhizome extract on germination percentage, shoot and root lengths. In glasshouse experiments fresh and dried shoot of S. syriaca added to soil drastically decreased germination and development of wheat.
Use of wild Setaria viridis (L.) Beauv. to improve triazine resistance in cultivated S. italica (L.) by hybridization
Authors: DARMENCY H. , PERNES J. 
Published: July 2006

SummaryInterspecific hybrids were obtained between two triazine‐resistant forms of the wild species Setaria viridis and the triazine‐susceptible cultivated foxtail millet (Setaria italica). The main agronomic characteristics of the hybrids were generally intermediate between the parental forms, except for fertility which was low. Some differences were observed according to the wild parent used. Progeny analysis confirmed the cytoplasmic inheritance of the resistance. The creation of resistant cultivars would allow the use of triazines in foxtail millet cultivation.
Control of Achillea millefolium L. (yarrow) by rotary cultivation and glyphosate
Authors: BOURDÔT G. W. , BUTLER J. H. B. 
Published: July 2006

SummaryVarious control strategies for Achillea millefolium L. (yarrow) were investigated in a dense stand of the weed at Lincoln College in 1977–1978. In early spring plots were either rotary cultivated or left undisturbed. In late spring, plots of both previous treatments were either left undisturbed, rotary cultivated or sprayed with glyphosate at 1·5 kg ha−1. The whole experiment was rotary cultivated twice 1 week later and sown with Hordeum vulgure L. cv. Zephyr (barley) at 144 kg seed ha−1. MCPA + dicamba at 0·9+0·15 kg ha−1 was applied to half of each plot when the second node was detectable (Zadok 32).Rotary cultivation and glyphosate both substantially reduced the regrowth of A. millefolium but glyphosate reduced regrowth by a greater proportion when applied to undisturbed plants than when applied to plants regenerating after cultivation. Both gave a more than 95% reduction compared to the control (rotary cultivation only at sowing time) in the amount of A. millefolium present in the barley stubble in the autumn.MCPA + dicamba caused seedling mortality but did not affect the numbers of primary shoots from rhizome fragments.The grain yield of the barley increased from 2·91 t ha−1 when A. millefolium was not controlled to 4·23 t ha−1 with good control. The barley yield appeared to be restricted by competition from regenerating A. millefolium and by a nitrogen deficiency induced in some regimes by nitrogen immobilization in decaying rhizomes.
Uptake and phytotoxicity of chlorsulfuron in Zea mays L. in the presence of 1,8‐naphthalic anhydride
Authors: O'LEARY NORA F. , PRENDEVILLE G. N. 
Published: July 2006

SummaryThe sites of uptake of chlorsulfuron in maize (Zea mays L.) were investigated at three different growth stages. Exposure of seedling roots, or shoots separately, to herbicide‐treated sand over 4 days resulted in inhibition of both roots and shoots. Exposure of seedling roots to chlorsulfuron‐treated soil over 21 days severely inhibited both roots and foliage, while separate shoot exposure also reduced both foliage and root growth. After plant emergence, exposure of the crown root node, growing point and lower stem to treated soil reduced foliage and root growth, but exposure of the shoot above the growing point caused only slight inhibition of foliage and had no effect on roots.The herbicide safener 1,8‐naphthalic anhydride (NA) applied as a dust (10 g kg−1 seed weight), or as a 50 mg 1−1 suspension in water to maize seeds, reduced the root inhibition by chlorsulfuron in 4‐day‐old seedlings. NA completely prevented both foliage and root injury when chlorsulfuron was placed in soil in the shoot zone before emergence, or in the shoot zone below the soil surface after plant emergence. NA slightly decreased injury to foliage, but not to roots when chlorsulfuron was placed in soil in the root zone before emergence. NA seed treatment protected both roots and foliage against injury from foliarly applied chlorsulfuron. Plants were also protected when a suspension of NA in water was sprayed on the foliage seven days before chlorsulfuron. When a mixture of NA and chlorsulfuron was applied to foliage, root injury was reduced more than foliage injury.
Effect of chlorsulfuron and 1, 8 naphthalic anhydride on uptake of 45Ca in maize
Authors: CROWLEY J. , PRENDEVILLE G. N. 
Published: July 2006

SummaryThe effect of chlorsulfuron on uptake of 45Ca was studied in maize (Zea mays L. cv. Earliking) plants grown from seeds dusted with 1, 8 naphthalic anhydride (NA). 45Ca absorption in sand‐grown maize was significantly decreased when chlorsulfuron was applied to the foliage but this was not so when seeds had been dusted with NA. Uptake of 45Ca was also reduced when either root or shoot soil zones were separately exposed to chlorsulfuron. When seeds had been dusted with NA, uptake of 45Ca from main roots was similar to that of untreated plants, but only when chlorsulfuron was localized in the shoot zone. NA did not counteract the severe reduction in 45Ca absorption when chlorsulfuron was localized in the root zone.
Behaviour of hard and permeable seeds of Abutilon theophrasti Medic. (velvetleaf)
Authors: HOROWITZ MENASHE , TAYLORSON R. B. 
Published: July 2006

SummaryExperiments were carried out on seeds of Abutilon theophrasti (velvetleaf) to examine the germination behaviour of hard (impermeable) and soft (permeable) seeds and to test various physical and chemical treatments against hardseededness. There was no evidence, in fresh or in old seeds, of leachable germination inhibitors or of leachable compounds affecting hardseededness.Marked differences were found between hard and soft seeds in respiration and leakage. Oxygen uptake was negligible in hard seeds. A rapid efflux of K+ ions from hard and soft seeds was detected during the first minutes of immersion. Subsequently, the rate of leakage of hard seeds decreased markedly. After 4 h of imbibition, conductivity measurements differentiated individual hard and soft seeds.Abrasion, percussion and immersion in sodium hypochlorite had no effect on hard seeds, but mechanical scarification and immersion in sulphuric acid reduced hardseededness. Gamma radiation did not affect the hard coat but damaged the embryo. A. theophrasti seeds were exposed to organic solvents such as acetone. ethanol and methanol, and to pesticides such as butylate, EPTC, metham‐sodium, vernolate and methyl bromide, in liquid or gaseous phase. Some of the treatments reduced germination of soft seeds, but none, even methyl bromide, had any significant effect on the number or viability of hard seeds, proving their complete impermeability.
Studies in the growth of Pteridium aquilinum (L.) Kuhn. (bracken) 1. Regeneration of rhizome segments
Authors: DANIELS R. E. 
Published: July 2006

SummaryThe patterns of regeneration of Pteridium aquilinum (L.) Kuhn. (bracken) rhizome segments grown in pot culture are described. The overall capacity for regeneration was unaffected by the rhizome type planted, i.e., whether it consisted of only a length of frond‐bearing ‘short shoote’ or whether this was attached to part of the main storage and exploratory ‘long shoot’. In all cases rhizomes extended, produced new lateral buds and developed fronds during the first summer. Regenerative capacity was also similar for segments with or without apical buds. Different patterns of growth were observed in plants grown from different types of segment: in particular, more new lateral buds were produced on rhizome segments originally lacking an apex. As rhizomes extended, the distance between successive lateral buds increased. The results are discussed in relation to the possible roles of correlative inhibition and patterns of translocation between fronds and rhizomes and to information on field populations.
Dégradation catalytique de carbamates et amides acétyléniques. Herbicides sur bentonites homoioniques: aspects particuliers
Authors: SABADIE J. , COSTE C. M. 
Published: July 2006

RásumáLa dégradation chimique d'herbicides acétyléniques (amides et carbamates) est étudiée en phase sèche sur diverses bentonites homoioniques (Fe3+, Mn2+, Cu2+, Zn2+). La bentonite Zn présente une activité intéressante vis à vis du propyzamide. L'influence de la dispersion du métal (ex: Cuivre) et de l'humidité de l'argile ont étéétudiées. La spectroscopie Infra Rouge a permis de préciser les groupes fonctionnels du substrat impliqués dans l'adsorption et de mettre qualitativement en évidence le phénomène de dégradation précédemment étudié.
Management of submerged aquatic macrophytes with terbutryne: availance, phytotoxicity and persistence
Authors: BOWMER K. H. , SHAW K. , ADENEY J. A. 
Published: July 2006

SummaryIn ideal conditions (static assay with long exposure time) several species of submerged weeds (Myriophyllum propinquum A. Cunn, Potamogeton tricarinatus F. Muell and A. Benn, and Vallisneria gigantea Graebner) were controlled by terbutryne at initial concentrations of <0·2 g m−3. However, since water management practices in irrigation systems limit the contact time which can be imposed, the availance (concentration‐time integral required for effectiveness) was further investigated, using Elodea canadensis Rich., which is dominant and widespread in the irrigation systems of south‐eastern Australia. In many experiments in irrigation channels, where control was poor, contact times were probably inadequate. Other factors may also contribute to inefficiency, including poor penetration of the weed beds after surface application, protection by high loadings of aufwuchs (periphyton, bacteria, detritus and associated particulate matter) on the leaves in the autumn, and inhibition of photosynthesis in an unfavourable light climate. Weed control was improved by injecting the herbicide into Mowing water, before ponding the treated water in the channels in spring or summer for at least 11 days. Terbutryne residues in the water decreased with a first order half‐life of about 9–20 days. Therefore, terbutryne is unsuitable for pulse injection treatment of flowing water in summer. Instead, effective control might be achieved by ponding the treated water in the channels in spring before the period of great water demand for summer crops. Contaminated water would be discarded onto tolerant crops or fallow land or retained in the system for about 7 weeks to ensure degradation of terbutryne before reuse.
Chemical weed control in transplanted onion (Allium cepa L.) in the Sudan Gezira
Authors: And A. G. T. BABIKER , AHMED M. K. 
Published: July 2006

Summary; Résumé; ZusammenfassungUnrestricted weed growth reduced the yield of transplanted onions (Allium cepa L.) by 26–48%. Hand‐weeding once, 42 days after transplanting reduced the yield loss to 15%. Application of oxadiazon (1.1–1.3 kg ai ha−1), pendimethalin (1.2–1.8 kg ai ha−1), oxyfluorfen (0.14–0.43 kg ai ha−1) and chlorthal‐dimethyl (8.3–13.1 kg ai ha−1) resulted in yields comparable to the hand‐weeded control (82–126%). When sprayed at transplanting these herbicides gave excellent and persistent control of grasses (86–100%). However, they were less effective on broad‐leaved weeds (38–94% control). Désherbage chimique de l'oignon repiqué (Allium cepa L.) dans la Gezireh soudanaiseLa croissance incontrôlée des mauvaises herbes réduit le rendement des oignons repiqués de 26–48%. Un désherbage manuel, 42 jours après le repiquage, ramène la baisse de rendement à 15%. L'application d'oxadiazon (1,1–1,3 kg ma ha−1), de pendiméthalin (1,2–1,8 ka ma ha1), d'oxyfluorfen (0,14–0,43 ka ma ha−1) et de chlortal‐diméthyle (8,3–13,1 kg ma ha−1), a permis d'atteindre des rendements comparables aux témoins désherbés manuellement (82–126%). Lorsqu'ils ont été administrés au moment du repiquage, ces herbicides ont permis un contrôle efficace et persistant des monocotylédones (86–100%). Toutefois, ils se sont montrés moins efficaces à l'égard des dicotylédones (38–94% du témoin). Chemische Unkrautbekämpfung in verpflanzten Zwiebeln (Allium cepa L.) in der Region Gezira (Sudan)Ungehinderte Unkrautentwicklung in verpflanzten Zwiebeln (Allium cepa L.) verringerte die Ernte um 26–48%. Eine Handjätung, 42 Tage nach dem Auspflanzen, reduzierte den Ernteverlust auf 15%. Die Applikation von Oxadiazon (1,1–1,3 kg ai ha−1), Pendimethalin (1,2–1,8 kg ai ha−1), Oxyfluorfen (0,14–0,43 kg ai ha−1) und Chlorthal‐ dimethyl (8,3–13,1 kg ai ha−1) erbrachte Ernten, die mit denjenigen, der von Hand gejäteten Kontrollparzellen vergleichbar waren (82–126%). Diese Herbizide, zur Ausflanzzeit ausgebracht, ergaben eine ausgezeichnete und andauernde Kontrolle von Gräsern (86–100%), während die Wirkung gegen breitblättrige Unkräuter geringer ausfiel (38–94%).
Studies of Salvia reflexa Hornem. IV. Effects of watering frequency, drought and nutrient supply on growth and development
Authors: WEERAKOON W. L. , LOVETT J. V. 
Published: July 2006

Summary: Résumé: ZusammenfassungPlants of Salvia reflexa Hornem. grown in pots of soil were subjected to drought treatments in glasshouse conditions. Quite short durations of water stress significantly decreased leaf area, top and root dry weight and the plants rapidly adjusted their water loss below potential evaporation rates. The plants survived and recovered from periods of drought for up to 30 days but plants dehydrated, even after short droughts, did not attain the growth rates of undroughted plants. In an infertile soil, S. reflexa plants demonstrated a large requirement for applications of phosphorus. With phosphorus applied, the species was also very responsive to nitrogen, and where both nitrogen and phosphorus were applied there were smaller responses to sulphur and potassium. Etudes sur Salvia reflexa Hornem. IV. Influence exercée sur la croissance et le développement de l'espèce par la fréquence des arrosages, la sécheresse et l'apport d'aliments Salvia reflexa Hornem., cultivé en vases de végétation, a été soumis à des régimes de sécheresse en conditions de serre. Une sécheresse, même de durée assez courte, a amené une diminution significative de la surface foliaire et du poids sec des parties aériennes ainsi que des racines; les plantes ont vite fait d'adapter leur perte d'eau à des niveaux inférieurs au taux potentiel d'évaporation. Elles ont survécu et se sont remises après des sécheresses de 30 jours maximum mais les plantes déshydratées, même pendant des sécheresses de courte durée, n'ont plus atteint le taux de croissance des plantes i indemnes de sécheresse. En terre pauvre, les plantes de S. reflexa ont exigé de grands apports de phosphore. Après les apports de phosphore, l'espéce a également fait preuve d'un grand besoin d'azote. En présence de phosphore et d'azote, la réponse aux apports de soufre et de potassium était moins forte. Untersuchungen an Salvia reflexa Hornem. IV. Einfluss von Wasserversorgung und Düngung auf das WachstumIn Gewächshausversuchen mit Salvia reflexa Hornem, nahmen bei relativ kurzzeitiger Trockkenperiode die Blattfläche und die Trockenmasse des Sprosses sowie der Wurzeln signifikant ab, so dass die Pflanzen die Transpiration schnell unter die potentielle Evaporationsrate senkten. Sie überlebten Trockenperioden von bis zu 30 Tagen und erholten sich wieder, erreichten aber, auch nach kurzem Wassermangel, nicht dieselben Wachstumsraten wie Pflanzen, die nicht dieser Belastung unterworfen waren. Auf einem nährstoffarmen Boden zeigten S.‐reflexa‐Pflanzen einen hohen Phosphatbedarf. Nach Phosphatdüngung braucht die Art auch viel Stickstoff. Bei N + P‐versorgten Pflanzen ist der Bedarf an Schwefel und Kalium gering.
Effects of temperature, light and certain growth regulating substances on sprouting, rooting and growth of single‐node rhizome and shoot segments of Paspalum distichum L.
Authors: HUANG W. Z. , HSIAO A. I. , JORDAN L. 
Published: July 2006

SummaryThe rate of sprouting, rooting and early growth of both single‐node stem and rhizome segments of Paspalum distichum L. increased as incubation temperatures increase to about 30°C and then declined at 40°C. There was little growth at 10°C. Single‐node shoots remained viable at cooler temperatures after 1 days’incubation at 45°C, and 35% remained viable after 2 days’incubation at 45°C. Both shoot and rhizome segments sprouted and rooted at alternating temperatures of 45°C/28°C and 45°C/22°C. Generally sprouting and rooting of shoot segments were faster than in rhizome segments, but the response to temperature was similar for both sprouting and rooting of single‐node shoot and rhizome segments. Single‐node shoot segments sprouted faster in 16‐h day lengths than in the dark. Rooting was better in the dark at 10°C, unaffected by light at 22 and 28°C, and faster in the light at 35 and 40°C. Sprouting, rooting and early growth were enhanced by gibberellin A3, kinetin and indole‐3‐acetic acid. Shoots collected at different seasons differed in their sprouting and rooting responses at various incubation temperatures. These patterns varying in response to seasonal temperature fluctuations may provide a survival mechanism for P. distichum.
Behaviour of the herbicide EL‐107 in wheat and rape grown under controlled conditions
Authors: CABANNE F. , LEFEBVRE A. , SCALLA R. 
Published: July 2006

SummaryThe behaviour of 14C‐EL‐107 has been evaluated in winter wheat and rape, which are tolerant and susceptible, respectively, under field conditions. After 10‐ to 13‐days’growth under controlled conditions, seedlings were allowed to absorb the herbicide through the roots. Two experiments were conducted to study the absorption and the metabolism of EL‐107. Absorption was estimated during a 5‐day treatment at the rate of 1–47 μM, and metabolism was studied after a 1‐day treatment at 14.7 μM. The results showed that (i) rape plants absorbed more herbicide than wheat, and translocated less radioactivity into their shoots, and (ii) the metabolism of EL‐107 proceeded actively only in the shoots, where EL‐107 disappeared at similar rates in the two species, giving rise to the same metabolites. In conclusion, the respective degrees of susceptibility of the two species could be partly related to differences in the concentration of the herbicide in the roots, where it can exert its phytotoxic effect.
Effect of sodium 2,2,3,3‐tetrafluoropropionate on the germination, emergence, growth and survival of pasture species
Authors: CAMPBELL M. H. , MURISON R. D. 
Published: July 2006

SummaryThe effect of sodium 2,2,3,3‐tetrafluoropropionate (tetrapion) on the germination, emergence, growth and survival of pasture species was ascertained in petri‐dishes (21 days) and in soil (114 days). Tetrapion was applied with the water in the petri‐dishes and to the soil surface prior to sowing seeds 2‐mm deep in plastic‐lined glasshouse trays. The rates applied in the petri‐dishes were 0,0.093, 0.187, 0.375, 0.75 and 1.5 kg a.i. ha−1; the same rates, except 0.093 kg a.i. ha−1, were applied in the glasshouse. In the petri‐dishes tetrapion did not affect germination rate nor germination capacity of any species. However, it severely reduced shoot growth (22–78% for the lowest and highest rate, respectively) and moderately reduced root growth per seedling (4–44% for lowest and highest rate). In the glasshouse trays, lower emergence, at 27 days, of five of the sown species on the 1.5 kg a.i. ha−1 treatment compared with the control, was explained by depression of shoot growth. Emergence was not affected at any other rate. Between day 27 and day 114 there was a progressive decline in the number of living seedlings of all species; the magnitude of deaths increased with time and rate of tetrapion. The rating of species for tolerance to tetrapion was: Medicago sativa > Festuca arundinacea > Dactylis glomerata > Phalaris aquatica > Eragrostis curvula. Although Trifolium subterraneum seedlings survived low rates of tetrapion they were still affected at day 114 whereas seedlings of other species were recovering. As tetrapion is readily leached from the soil profile, desirable species must be sown after sufficient rain has fallen to wash it from the soil. In this way it is possible to kill weed seedlings that germinate soon after spraying as well as to establish improved species.
Influence of soil moisture on activity and persistence of the strigol analogue GR 24
Authors: BABIKER A. G. T. , HAMDOUN A. M. , RUDWAN A. , MANSI N. G. , FAKI H. H. 
Published: July 2006

SummaryGermination of Striga hermonthica (Del.) Bentth seeds in response to the strigol analogue GR 24 was strongly influenced by soil moisture prior to, at, or after, stimulation. Exposure of seeds to excessive soil moisture contents (70% w/w) during conditioning resulted in a low response to GR 24. Transfer of Seeds from soil at 70% moisture to a lower moisture level (47%) for 2 days or more improved the response to GR 24 (37–58% germination), white air‐drying restored germination (88%). In Gezira soil the optimum soil moisture contents for maximum response to GR 24 were 44, 38 and 40% during conditioning, stimulation and germination, respectively. The corresponding figures for the sandy soil were 20, 22 and 22%, respectively. Persistence of GR 24 was similar in both soil types, but was strongly influenced by soil moisture content. The stimulant was stable in air‐dry soil, but a rapid loss was encountered in moist soil.